Registration Dossier

Administrative data

Description of key information

Repeated Dose Oral 90d – NOAEL 5000 mg/kg for rats (similar to OECD TG 408)
Repeated Dose Dermal 90d – NOAEL 495 mg/kg for rats, highest dose tested (similar to OECD TG 410)

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
short-term repeated dose toxicity: oral
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
a short-term toxicity study does not need to be conducted because a reliable sub-chronic (90 days) or chronic toxicity study is available, conducted with an appropriate species, dosage, solvent and route of administration
Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
June 1995 - October 1996
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to or similar to guideline study OECD 408: no data on GLP.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Deviations:
yes
Remarks:
Only female rats were used
GLP compliance:
not specified
Limit test:
no
Species:
rat
Strain:
Fischer 344
Sex:
female
Details on test animals and environmental conditions:
Source - Charles River Breeding Laboratories, Raleigh, NC
Age at purchase - Approximately 6 weeks
Age at study initiation - Approximately 9 weeks
Feed - Ad libitum (Purina Formulab #5002 - powdered)
Water - Ad libitum
Temperatures 21-25 deg C
Humidity - 40-60%
Light/dark cycle - 12/12 hours
Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
Neat n-nonane was administered orally (via gavage) on a daily basis throughout the study. Dosages were administered on the basis of weight of test substance (using a density correction of 0.72 g/mL for n-nonane) per animal body weight (not to exceed a volume of 1.0 mL/100 g body weight). Control animals received an equivalent volume (1 ml_/100 g body weight) of distilled water. Animals were not fasted prior to dosing, but dosing was scheduled towards midday (approximately 11:00 A.M.) since rodents eat, in general, during the night. Using a glass syringe, the test substance or distilled water was administered by stomach intubation through a commercial 18-gauge ball-end stainless steel needle.
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
90 days
Frequency of treatment:
7 days/week
Remarks:
Doses / Concentrations:
0, 100, 1000, 5000 mg/kg
Basis:
actual ingested
No. of animals per sex per dose:
10 female rats/dose group
Control animals:
yes, concurrent vehicle
Details on study design:
A range-finding 7-day study was used to select doses for the 90-day study. Rats were randomly stratified 10-each by body weight into 4 dose groups (0, 100, 1000 and 5000 mg/kg bw/day). Due to unexpected mortality during the first 4 days of dosing, 2 additional rats were assigned to group 4.
Observations and examinations performed and frequency:
Clinical observations - Yes. Twice daily.

Neurobehavioral tests - Two neurobehavioral tests were used to measure integrity of the motor system in rodents treated with nonane. Specifically, animals were tested forforelimb grip strength and overall locomotor activity. All animals of each dose group were tested pre-exposure (week -1), 4 weeks into the exposure period, and near the conclusion of the exposure period (week 12).

Grip strength - Animals were tested on a Columbus Instruments Automated Grip Strength Meter. The experimenter held individual animals such that the rear quarter was gently grasped and the forelimbs were unrestrained. The animal was placed over the dynamometer with the forehmbs in contact with the gripping screen. As the animal grasped the screen, the experimenter gently pulled the animal away from the meter until the animal released its grip. The force exerted by the grip was displayed on the grip meter and subsequently recorded by the experimenter. On each test day, individual animals completed five consecutive trials on the grip strength test. Scores from the five trials were averaged to produce one score per animal each test day.

Locomotor activity - Animals were individually placed in Columbus Instruments Opto-Vanmex Plexiglas open field measuring 30 cm2. Each 20 minute test session was divided into 10 two-minute blocks for the purpose of statistical analyses. Along the perimeter of the field are infrared photocells spaced one inch apart that detect quantity, size and direction of movement. In addition, there are infrared detectors at a second level used to detect vertical movements (rears). The apparatus automatically records the following types of motor movement: distance traveled, time spent resting, time spent in ambulatory movement, time spent in Stereotypie movement, number of Stereotypie movements and number of rears. The apparatus also analyzes rotational behavior by calculating the number of clockwise turns, number of counterclockwise turns and a ratio of clockwise to counterclockwise turns.

Body weights and food consumption - Body weights were determined and recorded immediately prior to the initiation of the study and weekly thereafter. Body weight gains were computed. Food consumption was determined and recorded weekly on an individual animal basis.
Sacrifice and pathology:
Hematology - following determinations were performed: hematocrit (HCT), hemoglobin (HGB) concentration, erythrocyte (red blood cell, RBC) count,
mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), total and differential leukocyte (white blood cell, WBC) count, and a measure of clotting potential (platelet count).

Serum chemistry - following determinations also were performed: calcium, phosphorous, chloride, sodium, potassium, glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), y-glutamyl transpeptidase, alkaline phosphatase, blood urea nitrogen (BUN), albumin, globulin, total protein, creatinine, and total bilirubin. A few additional measurements (e.g., cholesterol, triglycerides, magnesium) were performed on rat sera.

Necropsy - Examination of external surface of the body, all orifices and the cranial, thoracic and abdominal cavities were performed.

Organ weights - Kidneys, adrenals, gonads (all pairs), spleen, lungs and brain
Other examinations:
Histopathology - Tissues and organs (listed below) were collected from all study animals. Tissues and organs from animals of the control and high-dose groups, "target" tissues from animals of the lower nonane dose groups, and gross lesions (identified at necropsy) were subjected to histopathologic examination.
liver
kidneys
adrenals
pancreas
spleen
pituitary
thyroid/parathyroid
thymus
testes
ovaries
heart
trachea
nasopharyngeal tissues
esophagus
stomach
duodenum
jejunum
ileum
cecum
colon
rectum
urinary bladder
uterus
lungs
sternum with bone marrow
salivary glands
accessory genital organs (epididymis, prostate, seminal vesicles)
representative (ascending or descending) aorta
brain, including sections of medulla/pons, cerebellar cortex and cerebral cortex
spinal cord at three levels (cervical, midthoracic, and lumbar)
peripheral nerve
representative (submandibular or mesenteric) lymph nodes
Statistics:
Body weights and food consumption were intercompared using a repeated measures analysis of variance. Other continuous variables (e.g., organ weights, hematology and serum chemistry) were intercompared using an analysis of variance. Homogeneity of variance was tested using Levene's test. For significant F-values, multiple comparisons were conducted using a Bonferroni correction of t-tests. Nonparametric data were transformed and, if normal in distribution, parametric tests were performed. If the transformed data were not normal, appropriate nonparametric tests were carried out. Frequency data were compared using chi-squared tests and multiple comparisons were made using Bonferroni-corrected Fisher's Exact Test. The fiducial limit of 0.05 (two-tailed) was used as the criterion for significance when assumptions for homoscedasticity and normality were not violated.

Grip strength scores from the five trials were averaged to produce one score per animal each test day. The scores were subsequently analyzed in a repeated measures ANOVA. In the locomotor activity test, each 20 minute session was divided into 10 two-minute blocks for the purpose of statistical analyses. The different measures of motor activity were separately analyzed in repeated measures ANOVAs. Since the data were highly variable and not normally distributed, a Kruskal-Wallis analysis of variance was used for each test session, time block and dependent measure.
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
Clinical findings of irritancy in rats (wet urogenital areas, matted fur, alopecia etc). Mortality was due to oral gavage trauma
Mortality:
mortality observed, treatment-related
Description (incidence):
Clinical findings of irritancy in rats (wet urogenital areas, matted fur, alopecia etc). Mortality was due to oral gavage trauma
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
Mild to moderate perianal alopecia and inflammation in rats of the 5000 mg/kg dose group.Orally administered nonane was also irritating to the nonglandular stomach in rats at all dose levels with no apparent dose response.
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
There were statistically significant increases in mean liver and lung weights in the 5000 mg/kg dose group. Spleen weights were statistically significantly decreased in the 5000 mg/kg dose group while ovary weights were statistically significantly decreased in the 1000 and 5000 mg/kg groups. Changes in mean relative organ weights mentioned above were similar including a statistically significant increase in adrenal weights for the 1000 and 5000 mg/kg dose groups. Mean relative ovary weights were not changed in the 1000 mg/kg dose groups compared to mean organ weights. Though the decrease in ovarian weights were noted, there were no patholigical correlates and hence not considered adverse and likely incidental.
Dose descriptor:
NOAEL
Effect level:
ca. 100 mg/kg bw/day (actual dose received)
Sex:
female
Basis for effect level:
other: Small but significant changes in lung and adrenal weights
Critical effects observed:
not specified
Conclusions:
NOAEL was = 100 mg/kg bw/day on the basis of increased adrenal and lung weights
Executive summary:

In oral studies female rats and male mice were given n-nonane by gavage at 100, 1000 or 5000 mg/kg/day, 5 days/week for 12 weeks. There were no significant effects on body weight gain. There were small but statistically significant effects in some hematology parameters and serum chemistry values in rats from the high dose group. There were small but statistically significant increases in liver and lung weights and reductions in spleen and ovarian weights in the high dose group. Ovarian weights were also significantly below control values in the 1000 mg/kg/day group but were not significant when expressed relative to body weight. The only pathological findings that were reported were lesions of the forestomach, most likely due to repeated irritation associated with the high bolus doses of solvent. The ovarian weight effects in this study are an unusual observation, but, in the absence of any pathological findings, were most likely incidental.

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 408: GLP
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Principles of method if other than guideline:
According to EPA guideline 82-1
GLP compliance:
yes
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Sprague Dawley Inc.
- Age at study initiation: ca. 8 weeks
- Weight at study initiation: 238-295g (males); 180-236g (females)
- Housing: individual
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum):ad libitum
- Acclimation period: 16 days


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-76
- Humidity (%): 40-70
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 1990-12-17 To:1991-07-13
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Test material was mixed with corn oil to ensure a 10ml/kg dose volume at all dose levels.

Test material mixtures were administered by oral gavage at a dose volume of 10ml/kg. The control animals received carrier at a dose of 10ml/kg. The satellite group was dosed at the high dose level for the same duration as main test and allowed to recover for 28 days post-treatment.

VEHICLE
- Amount of vehicle (if gavage): 10ml/kg

Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
7 days/week
Remarks:
Doses / Concentrations:
5000 mg/kg
Basis:
actual ingested
Remarks:
Doses / Concentrations:
2500 mg/kg
Basis:
actual ingested
Remarks:
Doses / Concentrations:
500 mg/kg
Basis:
actual ingested
No. of animals per sex per dose:
10 animals/sex/dose
Control animals:
yes, concurrent vehicle
Details on study design:
Test material mixtures were administered by oral gavage at three different doses at a dose volume of 10ml/kg. The control animals received carrier at a dose of 10ml/kg. The satellite group was dosed at the high dose level for the same duration as the main test and allowed to recover for 28 days post-treatment.

- Post-exposure recovery period in satellite groups: 28 days post-treatment
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily monday-friday and once daily on weekends and holidays

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: prior to dosing, the day of dose initiation, and weekly thereafter

OPHTHALMOSCOPIC EXAMINATION: Yes
at study initiation and during the final week of the main study

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at main study termination and on satellite animals on the day of recovery sacrifice
- Anaesthetic used for blood collection: No
- Animals fasted: Yes
- How many animals:all

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at main study termination and on satellite animals on the day of recovery sacrifice
- Animals fasted: Yes
- How many animals: all

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Statistics:
The following parameters were statistically analyzed for significant differences: mean hematology parameters, serum chemistry parameters, organ weights, organ to body weight ratios, body weights, mean food consumption. Comparisons were limited to within sex analysis. Statistical evaluation of equality of means was done by an appropriate one way analysis of variance and a test of ordered response in the dose groups. First, Bartlett’s test was performed to determine if the dose groups have equal variance. If the variances were equal, the testing was done using parametric methods, otherwise nonparametric techniques were used.

For the parametric procedures, a standard one way ANOVA using the F distribution to assess significance was used. If significant differences among the means were indicated, Dunnett’s test was used to determine which treatment groups differ significantly from control. In addition to ANOVA, a standard regression analysis for liner response in the dose groups and linear lack of fit were preformed.

For the nonparametric procedure the test of equality of means was performed using the Kruskal-Wallis test. If significant differences among the means was indicated, Dunn’s Summed Rank test was used to determine which treatment group differ significantly from control. In addition, Jonckheere’s test for monotonic trend in the dose response was performed.

The statistical t-test was used to compare the satellite group’s main study termination and recovery termination hematology and clinical chemistry values. In addition, the t-test was used to compare the satellite group's and the control group's relative organ weights. The t-test was also used to compare the high dose and satellite groups to ensure similar results in order to accurately evaluate the recovery effects.
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
One male and 1 female died in the control group, 2 females died in the 2500 mg/kg dose group, 4 females died in the 5000 mg/kg dose group, 2 males and 3 females died in the satellite group. With the exception of one 2500 mg/kg female, all of the other 13 listed spontaneous deaths appear to be a result of dosing trauma and/or aspiration of test material (due to physical characteristics of test material and the high dosage volume).

The majority of animals in the control, low and mid dose groups displayed no observable abnormal clinical signs. Observations included but are not limited to scabs, maloccluded incisors, alopecia and staining of fur, dry/wet rales, dyspnea, nasal discharge. The type and incidence of abnormal clinical signs were similar between the high dose and satellite groups with a dramatic increase in incidence when compared to mid dose group. Clinical signs most frequently noted included swollen anus, ano-genital staining, emaciation, and alopecia. During the satellite recovery period, the incidence of abnormal signs decreased over time with an increase in the number of animals exhibiting no observable abnormalities.

BODY WEIGHT AND WEIGHT GAIN
Statistically significant decreases from controls at the p<=0.05 level of significance were noted for mid dose males on days 77, 84, 91 and termination and for the high dose males on Day 42. A statistically significant decrease (p<=0.01) was noted for the high dose group males on Day 49 and continued through the end of the treatment period. Statistically significant decreases were noted for mid dose females (p<=0.05) on day 91 and for high dose females on days 77 and 91. At termination both mid and high dose females displayed a statistically significant decrease in body weight.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Statistically significant increases in food consumption which were linearly related to dose were noted for males on Days 28 through 56 and Day 70 through termination. Significance levels were noted for both the mid and high dose males during these periods. These trends were also evident in the females where statistically significant increases in food consumption were noted on Days 21, 42, 49, and 63 through 95.

OPHTHALMOSCOPIC EXAMINATION
No treatment-related findings.

HAEMATOLOGY
A statistically significant increase in platelets which was linearly related to dose in both the males and females was observed. In addition the male animals displayed a linear dose related increase in white blood cells. The mid dose male values were noted to differ significantly from those of controls for hematocrit and hemoglobin at the p<=0.01 level of significance and mean corpuscular volume and mean corpuscular hemoglobin at the p<=0.05 level of significance.

CLINICAL CHEMISTRY
Statistically significant increases in males (p<=0.01) for urea nitrogen and gamma glutamyl transpeptidase for the high dose males and also the mid dose males for urea nitrogen. An increase for cholesterol was noted for the mid and high dose groups of both sexes (p<=0.01). An increase in alanine aminotransferase was also noted for the mid and high dose males (p<=0.01). Glucose levels were significantly lower than the control values (p<=0.01) for both sexes in the mid and high dose and for the male low dose (P<=0.05). A statistically significant increase in bilirubin in the high dose of both sexes was observed. Other parameters showing statistically significant differences from controls included creatinine, chloride, tryglycerides.

ORGAN WEIGHTS
Liver weights were elevated in male and female rats at 2500 and 5000 mg/kg/day. Adrenal weights were significantly increased in male and female rats at 5000 mg/kg and in female rats at 2500 and 5000 mg/kg. Testes weights were elevated in male rats at 5000 mg/kg. Both the male and female relative kidney weights for all treated groups were significantly different from the control value (p<=0.01).

GROSS PATHOLOGY
Most frequently observed abnormalities include small and large intestine distension (mid and high dose groups); swollen anus (high dose groups), staining of the fur (mid and high dose groups).
Dose descriptor:
NOAEL
Effect level:
>= 5 000 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: No treatment-related mortality or significant adverse clinical effects occurred.
Critical effects observed:
not specified
Conclusions:
The No Observed Adverse Effect Level (NOAEL) for following oral exposure to MRD-89-582 for 90-days is greater than or equal to 5000 mg/kg/day.
Executive summary:

MRD-89-582 was administered by oral gavage to rats at concentrations of 500, 2500 and 5000 mg/kg, 7 days a week for 13 weeks to assess the subchronic toxicity.  An additional group of animals, dosed at 5000 mg/kg/day, was held for 4 weeks to assess reversibility.  No treatment-related mortality was observed; however, male body weights were decreased while food consumption increased in the 2500 and 5000 mg/kg dose groups.  Liver weights were elevated in male and female rats at 2500 and 5000 mg/kg/day.  Adrenal weights were significantly increased in male and female rats at 5000 mg/kg and in female rats at 2500 and 5000 mg/kg.  Testes weights were elevated in male rats at 5000 mg/kg.  Kidney effects occurred in males at all dose levels, and are indicative of alpha-2u-globulin nephropathy.  Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats.  These complexes can accumulate in the proximal renal tubule and may produce species-specific histopathological changes.  These kidney effects are specific to male rats and are not considered to be of biological relevance to humans.

Dose-related changes in hematology or serum chemistry parameters were observed and were consistent with the changes seen in the liver.  Histological findings of hepatocellular hypertrophy (liver cell enlargement) were seen in livers of both sexes in all dose groups.  These findings are believed to have been a compensatory response and not an indication of toxicity.  Additionally, these liver effects were reversible and occurred only at high doses that are not typical of hydrocarbon exposures for humans.  Other treatment-related effects were mucosal thickening and other signs of irritation of the stomach and anus which appear to be the direct result of high dose intubation of a the locally irritating test substance.  These effects are believed to have been a compensatory response to local irritation and not an indication of toxicity.  All treatment-related effects were reversible within the 4-week recovery period.  Based on the results, the No Observed Adverse Effect Level (NOAEL) for the 90-day study was greater than 5000 mg/kg/day.

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
October 24, 1990 - September 27, 1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to or similar to guideline study OECD 408: no data on GLP.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
GLP compliance:
not specified
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
Source - Harlan Sprague Dawley Inc., Indianapolis, Indiana
Age at initiation of dosing - Approximately 6 weeks
Weight at dosing initiation - 156.2 - 223.2 g (males); 136.2 - 170.9 g (females)
Acclimation period - 16 days
Feed - ad libitum (purina certified rodent chow 5002)
Water - Ad libitum
Temperature - 68 - 76 deg F
Humidity - 40-70%
Lighting - 12/12 hours light/dark cycle
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
The test material mixtures were administered by oral gavage at a dose volume of 5 ml/kg, 7 days per week for a period of 13 weeks. The control animals received carrier at a volume of 5 ml/kg. The satellite group was dosed at the high dose level 7 days per week for 13 weeks and was then observed for reversibility, persistence or delayed occurence of toxic effects for 28 days post-treatment. The amount of test material administered t o each animal was recalculated weekly, based on the most recent body weight.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Aliquots of samples were diluted with toluene to a final analytical concentration of approximately 0.16 mg/ml. Standardization and quantitation was achieved by a one-point calibration of the neat material diluted in toluene to a concentration comparable to that of the samples. Reported concentrations are generally means of duplicate injections. Concentration verification analyses showed values to be within 7% of the target levels.
Samples of the 2% and 20% nominal concentration levels were kept in conditions of room temperature and refridgeration. Aliquots of these samples were analyzed on Day 0, Day 5 or Day 6, and Day 8. Stability was demonstrated for up to 9 days under conditions of both refrigeration and room temperature.
Aliquots of the 2% and 20% nominal concentration levels were analyzed in triplicate for uniformity. Uniformity was demonstrated at both dose levels.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
7 days/week
Remarks:
Doses / Concentrations:
0, 100, 500 and 1000 mg/kg day
Basis:
actual ingested
No. of animals per sex per dose:
10/sex/dose group
Control animals:
yes, concurrent vehicle
Details on study design:
Animals were randomly distributed to 5 dose groups. 0, 100, 500 and 1000 mg/kg day. The fifth group was dosed at 100 mg/kg day for 13 weeks and then sacrificed after a 28-day recovery (no treatment) period.
Observations and examinations performed and frequency:
The animals were checked for viability twice daily on Monday through Friday, and once daily on Saturdays, Sundays and holidays.
Clinical observations were made daily for the nature, onset and duration of toxicological signs. Body weights were recorded prior to dosing (pretest), on the day of dose initiation (Day 0 ) , and weekly thereafter. Body weights were also recorded at the scheduled sacrifice and at death for animals which succumbed prior to study termination.
Sacrifice and pathology:
clinical laboratory studies were performed for hematological and serum chemistry parameters pre-dose, interim (day 32 for males and day 33 for females) and at main study termination. Same parameters were performed on satellite animals on day of recovery sacrifice.
Other examinations:
Ophthalmoscopic examination was performed prior to study initiation and during final week of main study. Satellite animals were not examined during the final week of recovery. Gross necropsy was performed on animals at study termination and satellite animals (28-days post recovery period). Kidneys, ovaries, adrenals, liver, testes and brain were weighed prior to fixation. Other organs were fixed in 10% neutral buffered formalin.
Preserved tissues were processed, sectioned, stained (hematoxylin and eosin) and examined microscopically. Gross lesions, tissue masses, liver, lungs and kidney from the low and mid dose groups were also processed, sectioned, stained and examined microscopically.
Statistics:
The following parameters were statistically analyzed for significant differences:
mean hematology parameters
mean serum chemistry parameters
mean organ weights
mean organ to body weight ratios
mean body weights, by weighing period
mean food consumption

Comparisons were limited to within sex analysis. Statistical evaluation of equality of means was done by an appropriate one way analysis of variance and a test for ordered response in the dose groups. First, Bartlett' s test was performed to determine if the dose groups have equal variance. If the variances were equal, thetesting was done using parametric methods, otherwise nonparametric techniques were used.
For the parametric procedures, a standard one way ANOVA using the F distribution to assess significance was used. If significant differences among the means were indicated, Dunnett's test was used to determine which treatment groups ddiffer significantly from control. In addition to the ANOVA, a standard regression analysis for linear response in the dose groups and linear lack of fit were performed. For the nonparametric procedures the test of equality of means was performed using the Kruskal-Wallis test . If significant differences among the means were indicated, Dunn's Summed Rank test was used to determine which treatment group differ significantly from control. In addition to the Kruskal-Wallis test , Jonckheere's test for monotonic trend in the dose response was performed. The test for equal variance (Bartlett) was conducted at the 1% level of significance. All other tests were conducted at the 5% and 1% level of significance. The statistical t-test was used to compare the satellite group's main study termination and recovery termination hematology and clinical chemistry values. t-test was used to compare the satellite group's and the control groups relative organ weights. t-test was also used to compare the high dose and satellite groups to ensure similar results in order to evaluate recovery effects
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
Effects noted were within normal physiological range
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
no effects observed
Details on results:
Relative kidney and relative liver weights was statistically significantly increased for mid and high dose males. Relative testes weights were increased for high dose males but was not associated with histological or morphological changes. Relative liver weights was increasd for mid and high dose females. Rats showed a recovery trend in liver weights in satellite group rats indicating liver weight increases are a normal adaptive physiological response in the absence of pathophysiological correlates. Changes in kidney weights for recovery rats was not as notable. Histological changes in male rat kidneys included accumulation of hyaline droplets in cytoplasm of proximal tubules of the cortex, increased incidence of multifocal cortical tubular basophilia of tubular epithelium and dilated medullary tubules with granular casts. Changes were only observed in male rat kidneys and are typical of an alpha-2-u globulin-associated nephropathy.
Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: No adverse effects noted that are relevant to humans
Critical effects observed:
not specified
Conclusions:
Based on the data recorded in this study, the NOAEL for Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics is 1000 mg/kg.
Executive summary:

A 90-day subchronic study (similar to OECD TG 408) was conducted in Sprague-Dawley rats to assess the toxicity of Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics (CAS RN 64742-47-8) following OECD 408 guideline. The test substance was administered by oral gavage at a dose of 0, 100, 500, or 1000 mg/kg 7 days per week for a period of 13 weeks. The control animals received a carrier (corn oil) dose and a satellite group was dosed at 1000 mg/kg, 7 days/week for 13 weeks and was then observed for reversibility, persistence or delayed occurrence of toxic effects for 28 days post-treatment. Observations were made as to the nature, onset, severity, and duration of toxicological signs. There were no deaths attributed to the oral administration of Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics (two control group females died prior to termination. Kidney weights were elevated in male rats from the mid- and high dose groups, and liver weights were significantly elevated in female rats from the high dose group. The organ weight differences were not significant in animals held for 28 days without treatment. Pathological findings in kidneys from male rats were described as accumulations of hyaline droplets in the cytoplasm of the proximal tubules of the cortex, an increased incidence of multifocal cortical tubular basophilia with changes consistent with both degeneration and regeneration of the tubular epithelium and dilated medullary tubules with granular casts. The microscopic changes in the liver were described as minimal to slight centrilobular hepatocellular hypertrophy.   In the satellite group animals there was still evidence of changes in the kidneys but the liver weights had returned to control values. . There were no differences in weights of reproductive organs and no pathological changes. Based on the data recorded in this study, the NOAEL for Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics is 1000 mg/kg.

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
October 29, 1990 to October 29, 1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to or similar to guideline study OECD 408: no data on GLP.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
GLP compliance:
not specified
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
Supplier - Harlan Sprague Dawley Inc. Indianapolis, Indiana
Age at initiation of dosing - Approximately 8 weeks
Weight at initiation of dosing - 253.0 - 328.4 g (males); 172.3 - 229.1 g (females)
Acclimation period - 28 days
Feed - ad libitum (Purina certified rodent chow 5002 mash)
Water - Ad libitum
Temperature -
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
The test material mixtures were administered by oral gavage at a dose volume of 2.4 ml/kg, 7 days per week for a period of at least 13 weeks. The.control animals received carrier at a 2.4 ml/kg.. The satellite group was dosed at the high dose l e v e l seven days a week for approximately 13 weeks and was then observed for reversibility , persistence or delayed occurence of toxic effects for 28 days post-treatment. The amount of test material administered to each animal was recalculated weekly, based on the most recent body weight.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The stability , uniformity and the concentration verification of the test substance mixtures were determined by the testing laboratory. Stability was determined during the first week of study and concentration verification was performed every four weeks during the study.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
7 days per week
Remarks:
Doses / Concentrations:
0, 300, 600, 1000, 1000 mg/kg body weight
Basis:
actual ingested
No. of animals per sex per dose:
10 rats/sex/group
Control animals:
yes, concurrent vehicle
Details on study design:
10 rats/sex/group were randomized into 5 different dose groups: control group (0 mg/kg), 300, 600 and 1000 mg/kg bw. A fifth group (satellite) was also included with rats dosed at 1000 mg/kg bw for 13 weeks and then sacrificed 28 days post last treatment. Rats in group 4 and 5 were dosed at 1200 mg/kg on days 0-3 before doses were adjusted to 1000 mg/kg due to response displayed by the animals (ano-genital staining, emaciation and hypoactivity). Test material was mixed with corn oil vehicle to ensure a 2.4 ml/kg dose volume at all dose levels.
Observations and examinations performed and frequency:
The animals were checked for viabilit y twice daily on Monday through Friday, and once daily on Saturdays, Sundays and holidays.
clinical observations were made d a i l y for the nature, onset and duration of toxicological signs. Body weights were recorded prior to dosing (pretest), on the day of dose initiation (Day 0), and weekly thereafter , on the same day of the week. Body weights were also recorded at the scheduled sacrifice and at death for animals which succumbed prior to study termination.
Sacrifice and pathology:
Clinical laboratory studies (hematology and serum chemistry) were performed on all animals at main study termination. In addition, hematology and serum chemistry were also performed on the satellite animals on the day of recovery sacrifice. Blood samples were collected under methoxyflurane anesthesia from the orbital sinus of the animals which had been fasted overnight prior to blood collection.

Parameters evaluated:
Hematology:
erythrocyte count
hematocrit
hemoglobin
leukocyte count (total and differential)
mean corpuscular volume
mean corpuscular hemoglobin
mean corpuscular hemoglobin (concentration)
platelets
reticulocyte count

Serum Chemistry:
total bilirubin
albumin
blood urea nitrogen .
calcium
cholesterol
creatinine
electrolytes(Na+,K+,Cl-)
glucose
total protein
triglycerides
phosphorous
gamma glutamyl transferase
serum aspartate aminotransferase
serum alanine aminotransferase
Other examinations:
Opthalmoscopic examination - conducted prior to study initiation and during final week of main study. Satellite rats were examined in final week of recovery period.

A gross necropsy was performed on animals that succumbed during the study, those sacrificed at termination and those sacrificed after 28 days post-exposure ( satellite group). The necropsy included an examination of the external surface of the body, all orifices , and the cranial , thoracic, and abdominal cavities and their contents.
The. following organs were weighed prior to fixation for all animals sacrificed at termination:
kidneys
ovaries
adrenals
liver
testes

The following tissues and organs were taken and preserved i n 10% neutral buffered formalin for all animals:
adrenals
aorta
brain(3 levels)
epididymides
esophagus
eyes
femoris muscle with sciatic nerve
femur
heart
kidneys
large intestine (colon, cecum)
liver
lungs
mammary gland (female)
mesenteric lymph nodes
exorbital lacrimal gland
ovaries
pancreas
pituitary
prostate
rectum
salivary glands/cervical lymph node
seminal vesicles
small intestine (duodenum, jejunum, ileum)
spinal cord (cervical, midthoracic, lumbar)
spleen
sternum with marrow
stomach
testes
thymus(if present)
thyroid/parathyroids
trachea
urinary bladder
uterus (corpus/cervix)
all gross lesions

Preserved tissues from the control and high dose groups, as well as from all animals that were sacrificed moribund or succumbed during the study, were processed, sectioned, stained (hematoxylin and eosin) and examined microscopically. Gross lesions , tissue masses, and liver , lungs and kidney from the low and mid dose groups were also processed, sectioned, stained and examined microscopically. The stomach, spleen, urinary bladder and the thyroid of the low and mid-dose animals were also processed, sectioned, stained and examined microscopically due to changes seen in high dose group.
Statistics:
The following parameters were statistically analyzed for significant differences:
mean hematology parameters
mean serum chemistry parameters
mean organ weights
mean organ to body weight ratios
mean body weights, by weighing period
mean food consumption

Comparisons were limited to within sex analysis.. Statistical evaluation of equality of means was done by an appropriate one way analysis of variance and a test for ordered response in the dose groups. First, Bartlett' s test was performed to determine if the dose groups have equal variance. If the variances were equal, the testing was done using parametric methods, otherwise nonparametric techniques were used. For the parametric procedures, a standard one way ANOVA using the F distribution to assess significance was used. If significant differences among the means were indicated, Dunnett's test was used to determine which treatment groups ddiffer significantly from control. In addition to the ANOVA, a standard regression analysis for linear response in the dose groups and linear lack of fit were performed. For the nonparametric procedures the test of equality of means was performed using the Kruskal-Wallis test . If significant differences among the means were indicated, Dunn's Summed Rank test was used to determine which treatment group differ significantly from control. In addition to the Kruskal-Wallis test , Jonckheere's test for monotonic trend in the dose response was performed. The test for equal variance (Bartlett) was conducted at the 1% level of significance. All other tests were conducted at the 5% and 1% level of significance. The statistical t-test was used to compare the satellite group's main study termination and recovery termination hematology and clinical chemistry values. t-test was used to compare the satellite group's and the control groups relative organ weights. t-test was also used to compare the high dose and satellite groups to ensure similar results in order to evaluate recovery effects.
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
4 apparent treatment-related deaths in group 4 rats (high dose). Only 1 death was noted in group 5 rats (satellite) which was related to dosing trauma or aspiration similar to 1 group 3 female and 2 group 4 males. Most frequent abnormal clinical signs in high and satellite dose groups were ano-genital staining, alopecia and emaciation (primarily occurred in the first week when rats were dosed at 1200 mg/kg bw).
Mortality:
mortality observed, treatment-related
Description (incidence):
4 apparent treatment-related deaths in group 4 rats (high dose). Only 1 death was noted in group 5 rats (satellite) which was related to dosing trauma or aspiration similar to 1 group 3 female and 2 group 4 males. Most frequent abnormal clinical signs in high and satellite dose groups were ano-genital staining, alopecia and emaciation (primarily occurred in the first week when rats were dosed at 1200 mg/kg bw).
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Statistically significant decreases in terminal body weights for high dose males noted from day 7 to study termination (mostly reflective of the initial 1200 mg/kg bw dosing in days 0-3). No change observed in females.
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
Statistically significant decrease in RBC, HCT, Hb and MCHC. All within physiological range.
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
Significant increase in mean and mean relative kidney weights but not associated with pathological lesions
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
Increased hemosiderosis in red pulp of spleen in male and female rats at mid and high dose
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
centrilobular hypertrophy of the liver seen in the females at all dose levels and sporadically in the males along with a low incidence of periportal hepatocellular hypertrophy in the high dose males and/or female rats.
Histopathological findings: neoplastic:
no effects observed
Details on results:
For the recovery group, the relative organ weight, clinical chemistry and hematology data indicated recovery during the 28 day period after dosing. The satellite group's values for the recovery termination were similar to the control values seen at the main study termination. The liver changes seen at termination appeared to be reversible as they were not observed in the satellite group after the 28 day recovery period. The changes seen in the spleen, urinary bladder, thyroid and stomach at main study termination were observed at a lower incidence and/or severity in the satellite group after the 28 day recovery period also indicating reversibility . The hematology, serum chemistry, and the relative organ weights also indicated the reversibility of the effects.
Hyperplasia of the urinary bladder mucosa was most prevelant in the male rats and was noted in all dosage groups. This change was also noted in the mid and high dose females. There were no other changes noted during the study which would correlate with these changes.
Dose descriptor:
NOAEL
Effect level:
< 300 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: Urinary bladder effects noted in all males and mid and high dose females
Critical effects observed:
not specified
Conclusions:
BAsed on the changes noted in the urinary bladder, NOAEL for this test substance was less than 300 mg/kg bw/day
Executive summary:

A 90-day subchronic, repeated-dose, oral gavage study conducted on a C10-C13 Aromatic Hydrocarbon Solvents Category substance (CAS RN. 64742-94-5) showed a low order of systemic toxicity.

Animals (10/sex/dose group) were dosed with 0, 300, 600, or 1200 mg/kg/day (including a 28-day satellite recovery high-dose group) for three days. The doses for the satellite and high-dose animals were adjusted to 1000 mg/kg bw/day from the 4th day on due to the clinical response displayed in the first 3 days (ano-genital staining, emaciation and hypoactivity) in several animals. The majority of animals in the 300 and 600 mg/kg bw/day groups displayed no observable abnormalities during the test period. 

Changes in the liver were noted and include hypertrophy – predominantly centrilobular seen in the females at all dose levels and sporadically in the males along with a low incidence of periportal hepatocellular hypertrophy was seen in the high dose males and/or female rats. The changes corresponded to the significant increase in the mean liver weights (absolute and relative). A significant increase in the mean kidney weights (absolute and relative) was noted at termination but no corresponding changes in the kidneys were observed by the pathologist. Although the absolute testes weights at the highest dose level were not statistically different from control weights, the relative testes weights (relative to final body weight) were significantly increased only in the highest dose level due to the significantly decreased final body weights. These effects are considered to be an adaptive in response. There were no treatment-related histopathological changes in any testes examined.

The changes seen in the spleen, at the main study termination were at lower incidence and/or severity in the satellite recovery group also indicating a trend towards reversibility. Based on the results of this study, the LOAEL for this test material is 600 mg/kg bw/day and the NOAEL for this test material is less than 300 mg/kg bw/day.

Endpoint conclusion
Dose descriptor:
NOAEL
5 000 mg/kg bw/day
Study duration:
subchronic
Species:
rat

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
short-term repeated dose toxicity: inhalation
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
a short-term toxicity study does not need to be conducted because a reliable sub-chronic (90 days) or chronic toxicity study is available, conducted with an appropriate species, dosage, solvent and route of administration
Endpoint:
sub-chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study is classified as reliable without restriction because it is in compliance with OECD guidelines, as well as U.S. EPA/FIFRA, U.S. EPA/TSCA, and EU guidelines.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
according to
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
Qualifier:
according to
Guideline:
other: U.S. EPA/FIFRA Guidelines §82-4
Qualifier:
according to
Guideline:
EPA OTS 798.2450 (90-Day Inhalation Toxicity)
Qualifier:
according to
Guideline:
other: U.S. EPA/TSCA Guidelines 40 CFR §798.6059, and §798.6059, 798.6200, 798.6400
Qualifier:
according to
Guideline:
other: EU Guideline 87/302/EEC
GLP compliance:
not specified
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
not reported
Route of administration:
inhalation: vapour
Type of inhalation exposure:
not specified
Vehicle:
other: no data
Details on inhalation exposure:
not reported
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Concentrations were determined by gas chromatography.
Duration of treatment / exposure:
Rats were exposed to vapours of cyclopentane for 90 days.
Frequency of treatment:
6 hours per workday
Remarks:
Doses / Concentrations:
5, 10, 30 (pure), 30 (technical) mg/L
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
5.0±0.2, 10.0±0.3, 29.8±1.5 (pure), 29.8±1.8 mg/L
Basis:
analytical conc.
No. of animals per sex per dose:
15 males and 15 females per dose group
Control animals:
yes, concurrent no treatment
Details on study design:
not reported
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: yes
- Time schedule: General observation were made twice on weekdays and once on weekends and holidays.
- Cage side observations were not included in a table.

DETAILED CLINICAL OBSERVATIONS: yes
- Time schedule: Clinical examinations were made once per weekday during preflow and the on the day following exposure.

BODY WEIGHT: yes
- Time schedule for examinations: measured weekly

FOOD CONSUMPTION: not reported

FOOD EFFICIENCY: not reported

WATER CONSUMPTION: not reported
- Time schedule for examinations:

OPHTHALMOSCOPIC EXAMINATION: yes
- Time schedule for examinations: Examinations were carried out prior to and following exposure.
- Dose groups that were examined: not reported

HAEMATOLOGY: Yes / No / No data: yes
- Time schedule for collection of blood: Examinations of numerous parameters were preformed at the end of the exposure period.
- Anaesthetic used for blood collection: not reported
- Animals fasted: not reported
- How many animals: 10 males and 10 females

CLINICAL CHEMISTRY: yes
- Time schedule for collection of blood: Examinations of numerous parameters were preformed at the end of the exposure period.
- Animals fasted: not reported
- How many animals: 10 males and 10 females

URINALYSIS: not reported

NEUROBEHAVIOURAL EXAMINATION: yes (neurofunctional tests)
- Time schedule for examinations: performed three times during the exposure period (approximately once per month)
- Dose groups that were examined: not reported
- Battery of functions tested: not reported
Sacrifice and pathology:
A complete necropsy was performed on 15 animals per sex, which included weighing of selected organs and gross pathological evaluation.

5 animals per sex, of those subject to neurofunctional testing, were sacrificed by perfusion fixation and examined neuropathologically.
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not specified
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
No abnormalities were detected during clinical, neurofunctional, and clinico-pathological examinations in any of the test groups. No changes were found during necropsy or in the histo- and neuropathological examinations.
Dose descriptor:
NOAEC
Effect level:
30 mg/L air
Basis for effect level:
other: Equivalent to 30,000 mg/m3; 29.8 ± 1.5 (pure) or 29.8±1.8 (technical) mg/L air was the actual concentration
Critical effects observed:
not specified
Conclusions:
Subchronic inhalation exposure up to 30 mg/L of cyclopentane vapour (i.e, technical grade or high purity) did not cause a substance-related toxic effect. The NOAEC is 30 mg/L under the conditions of this study.
Executive summary:

Fifteen male and 15 female Wistar rats per test group were exposed to cyclopentane vapour (pure) at concentrations of 5, 10, 30 mg/L and cyclopentane vapour (technical grade) at a concentration of 30 mg/L for 6 hours per weekday for 90 days. A concurrent control group was exposed to clean air. General observation were performed twice during weekdays and once during weekends and holidays. Clinical examinations were performed once every weekday and on the day following exposure. Neurofunctional test were performed in 10 animals per sex, once before the exposure period and three times during the exposure period. A hematological and clinicochemical examination was performed in 10 animals per sex at the end of the exposure period. A complete necropsy was performed on 10 animals per sex, which included weighing of selected organs and gross pathological evaluation. 5 animals per sex, of those subject to neurofunctional testing, were sacrificed by perfusion fixation and examined neuropathologically. Subchronic inhalation exposure to up to 30 mg/L of cyclopentane vapour (i.e., technical grade or high purity) did not cause a substance related toxic effect. The NOAEC is 30 mg/L under the conditions of this study.

This study was given a Kilimsh score of 1, reliable without restriction. The study had minor discrepancies that are listed in the overall remarks/attachments comment box in this robust summary.

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1989-04-10 to 1989-07-12
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study is classified as reliable without restrictions because it is well documented and follows OECD Guideline 413.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
GLP compliance:
yes
Limit test:
yes
Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Raleigh, NC
- Age at study initiation: 8 weeks
- Weight at study initiation: approx. 181 g male, approx. 123 g female
- Housing: individually in stainless steel wire mesh cages, identified by tail tattoo
- Diet (e.g. ad libitum): Purina Rodent Chow Brand Animal Diet#5002, ad libitum
- Water (e.g. ad libitum): ad libitum, Elizabethtown Water Company
- Acclimation period: 20 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 68-75 degree F
- Humidity (%): 40-60
- Photoperiod (hrs dark / hrs light): 12 hrs light/12 hrs dark


IN-LIFE DATES: From: April 10, 1989 To: July 12, 1989
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Remarks on MMAD:
MMAD / GSD: Particle size measurements showed that there was no measurable amount of test substance present as aerosol.
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 1000 l glass and stainless steel exposure chamber
- Method of holding animals in test chamber: individual cages
- Source and rate of air: chamber supplied air, 200-216 lpm
- Method of conditioning air: Test substance in a 5-gallon drum passed through a fluid metering pump into teflon tubing to a coiled glass rod in the volatilization chamber. Nitrogen was also fed into the volitization chamber. A heating element was positioned in the center of the glass coil to aid volatilization. The nitrogen and test substance mixture, then entered the exposure chamber.
- Air flow rate: 200-216 lpm
- Air change rate: 4.6-5.0 min.

TEST ATMOSPHERE
- Brief description of analytical method used: GC
- Samples taken from breathing zone: yes, once per week

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Air samples were drawn from the chamber via teflon tubing into charcoal tubes.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
6 hrs/day, 5 days/week
Remarks:
Doses / Concentrations:
0, 900, 3,000, 9000 ppm
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
0, 904, 2,984, 8,992 ppm (0, 3182, 10504, 31652 mg/m3)
Basis:
analytical conc.
No. of animals per sex per dose:
10 animals of each sex per dose
Control animals:
yes, sham-exposed
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
- Cage side observations: mortality, toxicological and pharmacological effects


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: prior to test and week during the test


BODY WEIGHT: Yes
- Time schedule for examinations: twice prior to test, weekly during test and at termination


FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
Weekly beginning one week prior to test

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: prior to test and prior to sacrifice


HAEMATOLOGY: Yes
- Time schedule for collection of blood: prior to test on 10 animals per sex, and at sacrifice
- Animals fasted: Yes
- Anaesthetic used for blood collection: Yes, ether
- Parameters checked: erythrocyte count, hemoglobin count, hematocrit, total and differential leucocyte count, platelet count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: prior to test on 10 animals per sex, and at sacrifice
- Animals fasted: Yes
- Parameters checked: glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, creatinine, blood urea nitrogen, fasting glucose, total protein, alkaline phosphatase, albumin, potassium, sodium, calcium, chloride, inorganic phophorus, gamma glutamyl transpeptidase, total bilirubin, creatine phosphokinase, lactic acid dehydrogenase


Sacrifice and pathology:
GROSS PATHOLOGY: Yes
all orifices, cranial cavity, brain, spinal cord, nasal cavity, thoracic, abdominal, and pelvic cavities

ORGAN WEIGHTS: Yes
adrenals, ovaries, testes with epididymides, kidneys, liver, brain, lungs, heart, spleen


HISTOPATHOLOGY: Yes
abdominal aorta, adrenals, bone, bone marrow, brain, esophagus, eyes, optic nerve, larynx, ovaries, testes with epididymus, heart, kidneys, liver, intestine, gall bladder, lungs, lymph nodes, nerve, skeletal muscle, trachea, nasopharyngeal tissues, pancreas, pituitary, prostate, salivary gland, thymus, spinal cord, seminal vesicles, spleen, skin, stomach, thyroid, urinary bladder, uterus, exorbital lacrimal glands, Zymbal gland
Statistics:
Statistical analysis was done on body weight, body weight gain, change in body weight, food consumption, change in food consumption, hematology, clinical chemistry, organ weights, organ/body and organ/brain weight ratios.
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
not examined
Details on results:
CLINICAL SIGNS AND MORTALITY
No rats died during the study. Transient excess lacrimation was observed in the female rats. No other effects attibutable to exposure were noted.

BODY WEIGHT AND WEIGHT GAIN
Females in the high exposure group had sporadic reduced weight gain. As there was no consistant overall effect, this was not considered treatment related.

FOOD CONSUMPTION
There was no effect on food consumption.


OPHTHALMOSCOPIC EXAMINATION
Two males in the high exposure group showed corneal dystrophy. As this is not uncommon in males of this strain of rat, it is not considered treatment related.

HAEMATOLOGY
There were increased platelets in high exposure males. High and medium exposure males also had increased mean corpuscular volume. The significance of these changes are uncertain.

CLINICAL CHEMISTRY
High exposure males had increased creatinine, total protein, and albumin. They had decreased serum chloride. The significance of these changes are also uncertain.

ORGAN WEIGHTS
High exposure males had increased organ/body and organ/brain weight ratios. High exposure males and females had increased relative spleen weights. Liver weights were also increased in high exposure males. The liver effects appeared to be treatment related.

GROSS PATHOLOGY
No treatment related effects were noted.

HISTOPATHOLOGY: NON-NEOPLASTIC
There was hemorrhage and inflammation in male rat livers at the high dose level. There was also inflammation in the kidneys of males in the high and middle exposure groups. The significance of these effects are uncertain.



Dose descriptor:
NOAEC
Effect level:
2 984 ppm
Sex:
male
Basis for effect level:
other: 10504 mg/m3
Dose descriptor:
LOAEC
Effect level:
8 992 ppm
Sex:
male
Basis for effect level:
other: 31652 mg/m3; liver and kidney effects
Dose descriptor:
NOAEC
Effect level:
8 992 ppm
Sex:
female
Basis for effect level:
other: 31652 mg/m3
Critical effects observed:
not specified
Conclusions:
The NOAEC for male rats exposed via inhalation was 2984 ppm based on liver and kidney effects. The LOAEC for male rats was 8992 ppm. The NOAEC for female rats was 8992 ppm.
Executive summary:

The purpose of this study was to determine the sub-chronic toxicity of commercial hexane via inhalation. Groups of 10 male and 10 female rats were exposed to concentrations of 0, 904, 2,984, and 8,992 ppm of test substance for 6 hrs/day, 5 days/week, for 13 weeks. During the exposure period, animals were examined for mortality, body weight, clinical signs, opthamological effects, and food consumption. At the end of the exposure period, the animals were sacrificed and examined for hematological parameters, clinical chemistry, gross pathology, organ weights, and histopathology. There was no mortality among the exposed groups, and no treatment related effects to body weight gain. At sacrifice, the only possible treatment related effects were hemorrhage and inflammation in high dose male livers. The significance of this effect is uncertain. The NOAEC for male rats in 2984 ppm, and the LOAEC is 8992 ppm (10504 mg/m3). The NOAEC for female rats in 8992 ppm (31652 mg/m3).

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 413.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
GLP compliance:
yes
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Central Institute for the breeding of laboratory animals TNO, Zeist Netherlands
- Weight at study initiation: 35-50g
- Housing: individually
- Diet (e.g. ad libitum): ad libitum, removed during exposure
- Water (e.g. ad libitum): ad libitum, removed during exposure
- Acclimation period:1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.0-20
- Humidity (%): 40-60

IN-LIFE DATES: From: 13 January 1982 To: 16 April 1982
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
The test atmospheres are obtained as follows: filtered and dried air from the compressed—air line was passed through a glass evaporator, filled with isododecane. To obtain the desired isododecane concentration in the test atmosphere the airflow laden with isododecane was mixed in the proper ratio with the main airflow passed through the exposure chambers.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The analysis of test atmospheres to monitor the isododecane concentration was carried out by gas chromatography. Samples were taken automatically at regular intervals by means of a timer controlled 7-port gas-sampling valve. The sample loop was calibrated by comparing the area of the isododecane peak obtained from a loop sample with the area of the isododecane peak obtained from a sample taken simultaneously with a gas— tight syringe. The detector response to isododecane was calibrated by injecting known amounts of a standard solution of isododecane in diethylether.

The actual overall mean concentrations of isododecane in the various test atmospheres were 12.5, 50.2, 99.9 and 201.1 ppm.
Duration of treatment / exposure:
6h/day
Frequency of treatment:
5 days/week for 13 weeks
Remarks:
Doses / Concentrations:
0, 12.5, 50, 100 and 200ppm
Basis:
nominal conc.
No. of animals per sex per dose:
20 males and 20 females/dose group
Control animals:
yes
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations:just before the start of the first exposure and once every week thereafter

OPHTHALMOSCOPIC EXAMINATION:No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: weeks 6 and 12
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: 10 animals/sex/dose

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: weeks 6 and 12.
- Animals fasted: Yes
- How many animals:10 rats/sex/group


URINALYSIS: Yes
- Time schedule for collection of urine: weeks 6 and 12
- Animals fasted: Yes
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes (see table) / No / No data

The following organs were weighed:
adrenals lungs with trachea and larynx
brain pituitary
heart spleen
kidneys testes/ovaries
liver thymus
thyroid (with parathyroid)

Samples of the organs weighed and of the following tissues and organs were preserved in a neutral aqueous phosphate—buffered 4% formaldehyde solution.

Aorta, pancreas, axillary lymph nodes, parotid salivary glands, caecum, prostate coagulating glands, sciatic nerve, colon, seminal vesicles, duodenum, skeletal muscle (thigh), epididymides, skin (flank), spinal cord, eyes, sternum (with bone marrow), ileum, stomach, jejunum, submaxillary salivary glands, mesenteric lymph nodes, sublingual salivary glands, nose (sections at 4 levels), urinary bladder, oesophagus, uterus (with cervix), all gross lesions

The lungs were fixed (after weighing) by intratracheal infusion of the fixative under 10 cm water pressure.
The kidneys of all rats were embedded in paraffin wax, sectioned at 5 um, stained with haematoxylin and eosin, and examined by light microscopy.
Statistics:
Statistical analyses of body weights and organ to-body weight ratios were carried out using analysis of co-variance followed by the Dunnetts Test, whereas the haematological and biochemical data were evaluated by means of the Mann/Whitney U-test. For statistical analysis of the histopathological data, chi-square analysis was used.
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
no effects observed
Water consumption and compound intake (if drinking water study):
no effects observed
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
no effects observed
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
Health and behaviour of the rats of the test groups were not visibly affected by exposure to the test material. No mortality observed in this study

BODY WEIGHT AND WEIGHT GAIN
The animals, both males and females, of all test groups gained weight at a rate similar to that of the controls.

HAEMATOLOGY
Mean haematologic values include values obtained from rats in week 6 and 13. A few statistically significant differences occurred between test animals and controls. All values were increased with respect to the corresponding items of the control group. The differences occurred haphazardly among the exposure groups. Moreover, all values were within the range of “biological variability’, or expected values for rats of this strain and age, and there never was a clear dose-response relationship for any of the criteria concerned. Therefore, these findings are considered to be of no toxicological significance.

CLINICAL CHEMISTRY
Statistically significant differences between test animals and controls were found in parameters determined in week 7 and 13, most of them in week 13. However, some were increased and other decreased; they occurred randomly among the test groups; all were within the normal range found in rats of this strain and age, and moreover, in all cases there was no indication of a dose-response relationship for any of the criteria concerned. Therefore, no toxicological significance is attached to these findings.

URINALYSIS
No exposure-related alterations were observed for any of the parameters in any of the groups exposed to 12.5, 50, 100 or 200 ppm isododecane. The few statistically significant differences in specific gravity and in volume between males exposed to 50 or 200 ppm and control males in week 13, could not be correlated with the exposure levels and were within the range of normal values for rats of this strain and age.


ORGAN WEIGHTS
Absolute brain weight and lung-to-body weight ratios of males of the 100 ppm groups were statistically significantly different from those of the controls. Because these effects were observed in one of the intermediate dose groups only and because the differences were only marginal, no toxicological significance is attached to these findings.

GROSS PATHOLOGY
Macroscopical examination at autopsy did not reveal any gross lesions that could be attributed to the treatment. All lesions observed were either about equally distributed among the various groups or they occurred in one animal or in a few animals only.


HISTOPATHOLOGY: NON-NEOPLASTIC
Microscopical examination of the kidneys revealed a dose-related increase in incidence of tubular nephrosis. These lesions were characterized by a loss of cytoplasmatic eosinophilia and striation, a loss of the brush border, and an increased cellular and nuclear size of epithelium of mainly the proximal tubules. These changes were occasionally accompanied by very small to small aggregates of mononuclear inflammatory cells.

In males, statistical analysis of the data, comparing the various treatment groups with controls revealed a significant increase of the number of animals showing tubular nephrosis at the 50, 100 and 200 ppm exposure levels. In line with these findings a slight increase was found in the incidence of inflammatory cell infiltrates. Other changes observed in the kidneys, such as hydronephrosis and calcareous deposits occurred in one or two animals only, without any apparent relation to the treatment.
Dose descriptor:
NOAEL
Effect level:
>= 200 ppm (nominal)
Basis for effect level:
other: NOAEL >= 1160 mg/m^3, No treatment-related mortality or significant adverse clinical effects occurred.
Critical effects observed:
not specified
Conclusions:
The NOAEL for isododecane is greater than or equal to 200 ppm (≥1160 mg/m3, nominal, vapor) under the test conditions of this study.
Executive summary:

Five groups of rats, consisting of 20 males and 20 females each, were exposed to atmospheres containing 0, 12.5, 50, 100 and 200 ppm isododecane vapor for 6 hours a day, 5 days a week, for a period of 13 weeks. No treatment-related effects on mortality were observed and there were no significant alterations in hematological, blood chemical or urinary values, or in organ weights, which could be unequivocally attributed to treatment.  An increased incidence of minimal to slight tubular nephrosis was found in the kidneys of males at levels of 50 ppm and above.  These lesions were characterized by a loss of cytoplasmic eosinophilia and striation, a loss of brush border, and an increase in cellular and nuclear size of epithelium of mainly the proximal tubules.  The kidney effects observed in male rats are indicative of alpha-2u-globulin nephropathy.  Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats.  These complexes can accumulate in the proximal renal tubule and may produce species-specific histopathological changes.  These kidney effects are specific to male rats and are not considered to be of biological relevance to humans.  Based on these results, the No Observed Adverse Effect Level (NOAEL) was greater than or equal to 200ppm (1160 mg/m3).

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1980
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 413.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
GLP compliance:
not specified
Species:
rat
Strain:
other: albino
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Shell Toxicology Laboratory Breding Unit
- Age at study initiation: 10-13 weeks
- Housing: three of one sex per cage
- Diet (e.g. ad libitum): ad libitum except during exposure
- Water (e.g. ad libitum): ad libitum

During the period of the test the laboratory temperature varied between 19.4°C and 26.1°C and the relative humidity between 37% and 74%.
Barometric pressure was within the range 753 to 768 mm Hg


Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: no data
Details on inhalation exposure:
The atmospheres were generated by completely evaporating the solvent into the streams of ventilating air entering the chambers using micrometering pumps and vaporizers. The vaporizers consisted of electrically heated quartz tubes whose surface temperatures were adjusted during preliminary experiments to the minimal for complete evaporation of the solvent.

Each chamber was constructed of aluminum, with a volume of 1 m3 and was ventilated by air drawn from the laboratory through dust filters. The exhaust ducts from each chamber entered a common exhaust duct through which the air was drawn by a fan situated on the roof of the laboratory.

The total air flow rate through the main duct exhausting all four chambers was recorded continuously throughout the test by means of an electro—anemometer mounted in the duct. Slight adjustments were made as required to compensate for the effects of wind at the efflux point. The total flow rate was maintained at 2.0 + 0.03 m3 ∙min- 1. The individual flow rates through each chamber were balanced before the exposures began but were not checked further throughout the test since any significant changes would have been detected by the resulting changes in toxicant concentration. The flow rates were adjusted to 0.50 m3 ∙min- 1.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The test atmospheres were analyzed sequentially by means of a total hydrocarbon analyzer fitted with a flame-ionisation detector (Beckman 109A). The analyzer was calibrated during the test by means of known concentrations of SHELLSOL TD, prepared in a Teflon FEP gas sampling bag.

The recorder traces from the analyser were examined daily and a ‘daily mean concentration’ value was estimated by visual inspection. The daily mean concentrations for each of the test atmospheres were then ‘pooled’ to give weekly mean concentrations. The overall means of the weekly mean concentrations are given below:
Nominal concentration Observed concentration
(mg/m3) (mg/m3) (ppm)
10400* 10186 SD 327 1444
5200 5200 SD 207 737
2600 2529 SD 116 359
*83% saturated.

The desired concentrations of solvent in the test atmospheres were reached within 10 mm of the start of each exposure period. They then stayed remarkably constant throughout the 6 h exposure period.
Duration of treatment / exposure:
Six hours/day
Frequency of treatment:
five days/week for 13 weeks
Remarks:
Doses / Concentrations:
0, 2600, 5200, 10400 mg/m3
Basis:
nominal conc.
No. of animals per sex per dose:
6 animals/sex/dose (total of 12 animals/dose)
Control animals:
yes, sham-exposed
Details on study design:
The start and finish of the experiment was staggered in order that the optimum number of animals could be examined histopathologically after exposure. On each of four consecutive days, four male and four female rats per chamber were started on the experiment. The remaining two males and two females were started the next day. Thirteen weeks later, four male and four female rats per chamber were removed from the experiment for pathological examination on each of four consecutive days. The remaining two males and two females were removed the next day.
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule for examinations: daily

DETAILED CLINICAL OBSERVATIONS: Yes


BODY WEIGHT: Yes
- Time schedule for examinations: weekly


FOOD CONSUMPTION:
- Food consumption for each animal determined weekly: Yes


FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data


WATER CONSUMPTION: Yes
- Time schedule for examinations: weekly


OPHTHALMOSCOPIC EXAMINATION: No



HAEMATOLOGY: Yes
- Time schedule for collection of blood: 18h after the last 13 week exposure
- How many animals: all


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: 18h after the last 13 week exposure
- How many animals: all



URINALYSIS: Yes / No / No data
- Time schedule for collection of urine:
- Metabolism cages used for collection of urine: Yes / No / No data
- Animals fasted: Yes / No / No data
- Parameters checked in table [No.?] were examined.


NEUROBEHAVIOURAL EXAMINATION: No



OTHER:
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes for all animals exposed to the high and medium concentrations, plus the control animals. Kidneys of low concentration males were also examined.
Other examinations:
Organ weights
After post-mortem examinations the following organs were weighed:
Brain
Liver
Heart
Spleen
Kidneys
Testes

Histopatholgy. Tissues taken for histological examination were:

Mammary gland (posterior site with skin)
Mesenteric lymph node
Pancreas
Stomach
Intestine at 5 levels
Caecum
Spleen
Liver (middle, left and triangular lobes)
Adrenals
Kidneys
Ovaries or testes
Uterus or prostate
Seminal vesicles
Urinary bladder
Thyroid (with oesophagus and trachea)
Trachea (mid course and bifurcation)
Heart
Lungs
Nasal cavity
Thymus
Eye and lacrimal glands
Salivary gland (submaxillary)
Brain
Spinal cord (thoracic)
Pituitary
Tongue
Sciatic nerves
Muscle (femoral)
Knee joint and femur
Plus any other macroscopic lesion in any tissues.
The samples marked were held in 4% neutral formalin and only processed for histological examination if indicated by clinical or other pathological findings.
Statistics:
Body and organ weights were analysed by covariance analysis using initial body weight as the covariate. Reported means were adjusted for initial body weight if a significant covariance relationship existed: where no significant covariance relationship was found, unadjusted means were reported.

Organ weights were further examined by covariance analysis using the terminal body weight as the covariate. The organ weight means are reported as adjusted for terminal body weight if a significant covariance relationship existed. Although not a true covariance analysis (because the terminal body weights are dependent upon treatment), the analysis does provide an aid to the interpretation of organ weights when there are differences in terminal body weights. The analysis attempts to predict what the organ weights would have been, had all the animals had the same terminal body weight.
Clinical, chemical and haematological parameters were examined using analysis of variance.

The analysis allowed for the fact that animals were multihoused. Differences in response can be affected by cage environment as well as by treatment but this effect is minimal in a study of this duration.
The significance of any difference between treated and control group means was tested using the Williams t test (1971, 1972). However, if a monotonic dose response could not be assumed Dunnett’s test (1964) was used.
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
no effects observed
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
No deaths were recorded and clinical signs of toxicity were absent in the low and medium exposure groups; the high exposure groups were slightly lethargic when examined up to one hour after cessation of exposure. Body weight gain was slightly reduced in all female groups and in high exposure males. Water intake was increased in the high exposure males only.

Female aspartate amino transferase and alanine amino transferase were decreased in all female groups exposed to SHELLSOL-TD. No pathological changes were detected which could explain the observed decreases in these enzymes. In view of this lack of supporting evidence and the fact that the control values for these two parameters were high when compared with historical controls in the laboratory, these changes were not considered toxicologically significant.

Male alkaline phosphatase, potassium, chloride and albumin were increased at the high exposure level. These were considered to represent biological variation in the rat and were not considered treatment-related.

Male kidney weights were increased at all exposure levels. Hyaline intracytoplasmic inclusions and an increased incidence of tubular degeneration and/or dilatation were seen in the cortical tubules of all exposed males. These are a common effect observed in repeated-dose animal studies with hydrocarbon solvents. These kidney changes have been identified to result from an alpha2u-globulin-mediated process that because of its sex and species specificity, is not regarded as relevant to humans.

A low grade anemia was evident in all males exposed to SHELLSOL TD, characterized by slight reductions in haemoglobin, packed cell volume and total erythrocyte counts. Splenic weight was increased in the high concentration males. These changes were not seen in females and were not considered dose-related and therefore considered not toxicologically relevant.

Male and female liver weights were increased at the high and medium exposures, and male liver weights at the low exposures also. No lesions were identified histologically in the livers of treated animals that could account for the increased weight. This change was considered a physiological response to exposure rather than a toxic response and as such is not of toxicological significance.
Dose descriptor:
NOAEC
Effect level:
> 10 400 mg/m³ air (nominal)
Sex:
male/female
Basis for effect level:
other: No treatment-related mortality or significant adverse clinical effects occurred.
Critical effects observed:
not specified
Conclusions:
The NOAEC for SHELLSOL TD is 10186 mg/m3 (actual) (1444 ppm) under the test conditions of this study.
Executive summary:

SHELLSOL TD was administered by inhalation to albino rats for 6 hours/day, 5 days/week for 13 weeks at nominal vapor concentrations of 10400 mg/m3, 5200 mg/m3, and 2600 mg/m3 to assess inhalation toxicity.  No mortality or treatment-related effects in any of the hematology and serum chemistry values were observed.  Liver and kidney weights were increased in male rats at all exposure levels, male heart weights were increased at the highest exposure level and liver and kidney weights were increased in female rats at 10400 mg/m3.  In addition, the male rats exposed to SHELLSOL TD at all concentrations showed tubular degeneration and hyaline inclusion-droplets in the epithelium.  There was also scattered degeneration of the proximal renal tubules which showed cytoplasmic pallor and shrinkage. Occasionally the degenerate tubules were surrounded by a lymphocyte infiltrate. Many tubules also showed dilatation of the cortico-medullary junction, the dilated tubule being filled with a flocculent eosinophilic material. The kidney effects observed in male rats are indicative of alpha-2u-globulin nephropathy.  Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats.  These complexes can accumulate in the proximal renal tubule and may produce species-specific histopathological changes.  These kidney effects are specific to male rats and are not considered to be of biological relevance to humans.  Histopathological examination did not reveal any abnormalities that were considered treatment related.  As there were no pathologic changes, changes in organ weights mentioned above were judged to have been compensatory rather than toxic effects.  Based on these results, the No Observed Adverse Effect Concentration (NOAEC) was greater than or equal to 10400 mg/m3.

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
17 April 1978 - 30 March 1979
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions. Limited documentation on animal housing, only 2 concentrations tested, exposure duration 84 days, no ophthalmological examination.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
GLP compliance:
no
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Wilmington, Mass. 01887
- Age at study initiation: males 6 wks, females 7 wks
- Weight at study initiation: males 185 g mean (range 165-217 g); females 162 g mean (range 138-189)
- Fasting period before study: no
- Housing: paired in chamber, individual out of chamber
- Diet (e.g. ad libitum): Standard laboratory pellet diet (Purina Laboratory Chow) ad libitum (out of chamber only)
- Water (e.g. ad libitum): ad libitum (out of chamber only)
- Acclimation period: 13 days
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Remarks on MMAD:
MMAD / GSD: not applicable, vapour
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: stainless steel and glass chambers with 1 cubic meter total volume (760 L effective volume)
- Source and rate of air:
- Method of conditioning air:
- System of generating particulates/aerosols:
- Temperature, humidity, pressure in air chamber:
- Air flow rate: 134 L/min
- Air change rate: 8 per hour
- Method of particle size determination: not applicable, vapour


TEST ATMOSPHERE
- Brief description of analytical method used: Atmospheric sampling was performed using a Wilks Scientific Corp., Miran 1A Ambient Air Analyzer (long pathlength infrared). A calibration curve relating the absorption to the airborne concentration of the test material was prepared. On each exposure day, three samples were drawn from each exposure chamber (at about 1, 3, and 5 hours) and the exposure concentration calculated by comparing the absorption of this sample to the standard curve.
In addition, the composition of the test atmosphere was analyzed for homogeneity by gas chromatographic analysis of several charcoal-trapped vapour samples collected from each chamber during the 12-wk exposure period
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The test atmosphere was analysed for concentration and homogeneity by measurement of the infrared spectrum and by gas chromatographic analysis, respectively. Based on the infrared analysis the animals were exposed to cumulative mean concentrations of 385 and 1200 ppm, respectively. Gas chromatographic analysis of the chamber atmosphere demonstrated that the test material composition was representative of the initial sample.
Duration of treatment / exposure:
12 weeks
Frequency of treatment:
6 hours/day, 5 days/week
Remarks:
Doses / Concentrations:
400, 1200 ppm
Basis:
nominal conc.
No. of animals per sex per dose:
35
Control animals:
yes, sham-exposed
Details on study design:
- Rationale for animal assignment (if not random): assigned to group by weight
Positive control:
none
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations included: incidence of abnormal signs


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly (full recorded physical assessment)


BODY WEIGHT: Yes
- Time schedule for examinations: weekly, from 5 days prior to exposure through termination


WATER CONSUMPTION: No


OPHTHALMOSCOPIC EXAMINATION: No


HAEMATOLOGY: Yes (retro-orbital sinus)
- Time schedule for collection of blood: 4, 8, 12 weeks
- Anaesthetic used for blood collection: Yes (exsanguination under ether anesthesia)
- Animals fasted: Yes (fasted overnight prior to bleeding)
- How many animals: 10/sex/group (4 and 8 weeks), 15/sex/group (12 weeks, all survivors)
- Parameters examined: hemoblobin, hematocrit, erythrocyte count, clotting time, total and differential leukocytes


CLINICAL CHEMISTRY: Yes (retro-orbital sinus)
- Time schedule for collection of blood: 4, 8, 12 weeks
- Animals fasted: Yes (exsanguination under ether anesthesia)
- How many animals: 10/sex/group (4 and 8 weeks), 15/sex/group (12 weeks, all survivors)
- Parameters examined: blood urea nitrogen, serum glutamic pyruvic transaminase (SGPT), glucose, alkaline phosphatase


OTHER:
Organ weights and organ/body weight ratios determined in animals sacrificed at 4, 8 and 12 weeks (adrenals, brain (sans pituitary), gonads, kidneys, liver, lungs)
Sacrifice and pathology:
GROSS PATHOLOGY: Yes: adrenals, brain (without pituitary), gonads, kidneys, liver, lungs
HISTOPATHOLOGY: Yes (control and 1200 ppm group): adrenals (2), bone marrow (sternal), brain (2 sections), eye, gonad, heart (with coronary vessels) intestine, colon, duodenum, ileum, kidneys (2), liver (2 sections), lung (2 sections), lymph node (mesenteric), mammary gland, pancreas, pituitary, salivary gland, skeletal muscle, skin, spinal cord (cervical), spleen, stomach, thyroid, trachea, urinary bladder, uterus/prostate, gross lesions, tissue masses
Statistics:
Body weight, hematology and clinical chemistry parameters, organ weights and organ/body weight ratios were statistically evaluated. Mean values for all treatment groups were compared to the control group at each time interval (4, 8, and 12 weeks). Hematology and clinical chemistry parameters were compared by the F-test and Student's t-test. When variances differed significantly (F-test), Student's t-test was appropriately modified using Cochran's approximation (t'). Body weight, organ weight and organ/body weight ratios were compared to control according to Dunnett.
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not specified
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not specified
Behaviour (functional findings):
not specified
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
not examined
Details on results:
CLINICAL SIGNS AND MORTALITY
No treatment-related mortality occured (1 male of the 1200 ppm group was accidentally killed).
Several animals in all groups exhibited dry rales and red and mucoid nasal discharge (more numerous in the treated groups, but not clearly treatment-related), moist rales, excessive lacrimation, hair loss and chromodacryorrhea were found in a limited number of animals in all groups (not treatment-related)
1200 ppm: singular occurrences of excessive salivation, laboured, irregular breathing; yellow staining of the anogenital fur in 6 males and 35 females from wk 3 through 12
400 ppm: yellow staining of the anogenital fur in 2 females
Control: singular occurrences of excessive salivation and bleeding inside the ear; a limited number of animals with brown staining of the ano-genital region and soft stool; three observations (in one animal) of an abnormally dark red or red and yellow eye

BODY WEIGHT AND WEIGHT GAIN
1200 ppm: mean body weights in males significantly higher at wk 2 and significantly lower (p?0.05) from wk 8 through 11 than in controls
400 ppm: mean body weight and weight gains in males similar to control throughout the study, except wk 2 (significantly higher, p?0.01), in females mean body weights significantly depressed (p?0.01 and p?0.05) at wk 5 through 8.

HAEMATOLOGY
Several statistically significant (p < 0.05 and p < 0.01) decreases in mean hematocrit values of males and females of both treated groups at wk 4 and 8, statistically significant decreases (p?0.05) in mean hemoglobin values at wk 8 in the males of both treated groups and the females of the 400 ppm group at wk 4. Mean red blood cell values were significantly decreased in 1200 ppm males at wk 8 and 400 ppm females at wk 12. Since all values were within normal biological limits, these findings were not considered to be treatment-related.

CLINICAL CHEMISTRY
Mean SGPT levels were significantly (p?0.01) depressed in 1200 ppm males at wk 4, 400 and 1200 ppm males at wk 8, and in 1200 ppm females at wk 12. Mean blood urea nitrogen levels were significantly increased in the males of both treated groups at wk 8. Mean glucose levels were significantly (p?0.01 or p?0.05) increased in 400 ppm males at wk 8, decreased in 1200 ppm males at wk 12, and decreased in 1200 ppm females at wk 4 and 12. The observed effects were not considered to be treatment-related.

ORGAN WEIGHTS
Mean kidney weights and kidney/body weight ratios were significantly (p?0.05) higher in the 1200 ppm males at wk 8. In the 400 ppm males these values were also elevated, but not statistically significant. At wk 12, mean kidney weights and kidney/body weight ratios for 400 and 1200 ppm males were significantly (p?0.01) elevated, indicating a treatment-related response. The only other statistically significant (p?0.05) findings were elevated mean adrenal/body weight ratios for the 1200 ppm males at wk 4 and the 400 ppm females at wk 12.

GROSS PATHOLOGY
Microscopic evaluation of organs and tissues from the control and high level exposure groups revealed a mild tubular injury in the kidneys of some exposed male rats sacrificed after exposure for 8 and 12 wk. Other changes were unrelated to group or sex and were considered to be spontaneous.

HISTOPATHOLOGY: NON-NEOPLASTIC
See Gross Pathology
Dose descriptor:
NOAEC
Effect level:
1 200 ppm (nominal)
Sex:
male
Basis for effect level:
other: overall effects
Critical effects observed:
not specified

Significantly increased mean kidney weights and kidney/body weight ratios were observed in males at 400 ppm, which were considered to be treatment-related by the authors of the study. The kidney was confirmed as potential target organ for the test material-induced toxicity by the observation of mild tubular injury found in the histopathological examination of high dose males. The fact, that these effects were strictly limited to male rats and that the test substance belongs to a category of substances which are known for their ability to induce nephropathy in male rats due to their exclusive expression of alpha-2u-globulin, the protein known to play the crucial role in the onset of this disease, the observed effects in the kidney have to be regarded as species-specific and therefore not relevant for risk assessment in humans. Therefore, these effects were not considered for the determination of the NOAEC.

Conclusions:
In a 12 -week inhalation study with rats the test substance hydrocarbons, C7 -C9, isoalkanes was tested. Significantly increased mean kidney weights and kidney/body weight ratios were observed in males at 400 ppm, which were considered to be treatment-related by the authors of the study.

The kidney was confirmed as potential target organ for the test material-induced toxicity by the observation of mild tubular injury found in the histopathological examination of high dose males.

The fact, that these effects were strictly limited to male rats and that the test substance belongs to a category of substances which are known for their ability to induce nephropathy in male rats due to their exclusive expression of ?2u-globulin, the protein known to play the crucial role in the onset of this disease, the observed effects in the kidney have to be regarded as species-specific and therefore not relevant for risk assessment in humans. Therefore, these effects were not considered for the determination of the NOAEC.

Renal effects were strictly limited to males, therefore the authors concluded an alpha-2u-globulin-related mechanism for the observed nephropathy. The observation was not considered for determination of the NOAEC.
Executive summary:

In a 12 -week inhalation study with rats the test substance hydrocarbons, C7 -C9, isoalkanes was tested. Significantly increased mean kidney weights and kidney/body weight ratios were observed in males at 400 ppm, which were considered to be treatment-related by the authors of the study. The kidney was confirmed as potential target organ for the test material-induced toxicity by the observation of mild tubular injury found in the histopathological examination of high dose males. The fact, that these effects were strictly limited to male rats and that the test substance belongs to a category of substances which are known for their ability to induce nephropathy in male rats due to their exclusive expression of alpha-2u-globulin, the protein known to play the crucial role in the onset of this disease, the observed effects in the kidney have to be regarded as species-specific and therefore not relevant for risk assessment in humans. Therefore, these effects were not considered for the determination of the NOAEC. Renal effects were strictly limited to males, therefore the authors concluded an alpha-2u-globulin-related mechanism for the observed nephropathy. The observation was not considered for determination of the NOAEC.

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
1978
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 413.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
GLP compliance:
not specified
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
Test animal source - Charles River Breeding Laboratories, Wilmington, MA 01887
Age at receipt - 6 weeks (male), 7 weeks (female)
Weight at study start - 159-198 g (males; average 180 g); 137 - 181 g (females; average 156 g)
Food - Ad libitum (purina lab chow)
Water - Ad libitum
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
air
Details on inhalation exposure:
Appropriate amounts of the test material were transferred from a reservoir using a metering pump into a heated flask and flash evaporated. A stream of clean air was also passed through the flask and the vapor laden air transferred to a port in the chamber air inlet, where it was diluted with normal chamber intake air to give the desired concentration. Adjustments in the exposure air concentration were made by changing the rate of flow of test material through the metering pump. The stainless steel and glass chambers in which t|ie animals were exposed had an effective exposure volume of 760 liters. They were operated dynamically at a flow rate of approximately 135 liters per minute. This provided one air change every 5.6 minutes and a 99% equilibrium time of 26 minutes.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Atmospheric sampling was performed using a Wilks Scientific Corp., Miran IA Ambient Air Analyzer (long pathlength infrared). The infrared spectrum of the test material was measured and a strong band associated with the test material was observed at 3.4 microns. A calibration curve relating the absorption at this wave length to the airborne concentration of the test material was prepared. On each exposure day three samples were drawn
from each exposure chamber (at about one, three and five hcurs) and the exposure concentration calculated by comparing the absorption of this sample to the standard curve. In addition, the composition of the test atmosphere was analyzed for homogeneity by gas chromatographic analysis of
hexane scrubber samples collected from each chamber during the 12 week exposure period.
Duration of treatment / exposure:
12 weeks
Frequency of treatment:
6 hr/day, 5 days/week
Remarks:
Doses / Concentrations:
0, 300, 900 ppm
Basis:
nominal conc.
No. of animals per sex per dose:
35 rats/sex/dose group
Control animals:
yes, sham-exposed
Details on study design:
Rats were assigned to groups by weight. There were 70 rats in total/group - 20 rats were sacrificed at week 4 and 8 respectively with the remaining 30 sacrificed at 12 weeks
Observations and examinations performed and frequency:
Animals were observed daily for incidence of abnormal signs and a full, recorded, physical assessment was performed weekly. Individual body weights were recorded weekly from ten days prior to exposure through termination (including the first day of exposure - Day 0 )
Sacrifice and pathology:
Body weight, hematology and clinical chemistry parameters, organ weights and organ/body weight ratios were analyzed. Mean values for all dose groups were compared to control groups at each time interval. Statistically significant differences from control were indicated.
Blood Collection: From retro-orbital sinus (Parameter Evaluated:)
Hematology (hemoglobin, hematocrit, erythrocyte count, clotting time, mean corpuscular volume, total and differential leukocytes)
Clinical Chemistry (blood urea nitrogen, serum glutamic pyruvic transaminase, glucose, alkaline phosphatase)

Organs Weighed:
adrenals
brain (sans pituitary)
gonads
Kidney
Liver
Lungs

Tissues Fixed: (all animals)
adrenals
bone marrow (sternal)
brain (2 sections)
eye (2)
gonads (2)
heart (with coronary vessels)
intestine (colon, duodenum, ileum)
kidneys
liver (2 secti ons)
lung (2 sections)
lymph node (mesenteric)
mammary gland
pancreas
pituitary
salivary gland
skeletal muscle
skin
spinal cord (cervical)
spleen
stomach
thyroid
urinary bladder
uterus/prostate
gross lesions
tissue masses

Eyes and testes were fixed with Bouin's solution while all other tissues were fixed in 10% neutral buffered formalin
Statistics:
Compound-treated groups were compared to control by the F-test and Student's t-test. When variances differed significantly (F-test), Student's t-test was appropriately modified using Cochran's approximation.
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
Increased kidney and liver weights in males. Increased liver weights in females
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
Absolute and relative kidney weights were increased for males in the 900 ppm group (relative weights were increased for males in the 300 ppm group). Absolute liver weights were increased for 900 ppm males. In females, 900 ppm group showed a statistically significant increase in relative and absolute liver weights. All these changes were not considered adverse effects.
Dose descriptor:
NOAEC
Effect level:
>= 900 ppm (nominal)
Sex:
male/female
Basis for effect level:
other: No adverse effects of test substance exposure
Critical effects observed:
not specified
Conclusions:
NOAEC was greater than or equal to highest dose tested (900 ppm)
Executive summary:

A test material identified as “Hydrocarbons, C10 - C12, isoalkanes, < 2% aromatics (CAS RN 64742-48-9)” was administered by inhalation to Sprague-Dawley rats at vapor concentrations of 300 or 900 ppm for 6 hours/day, 5 days/week for 12 weeks following a study design consistent with OECD 413. No treatment-related effects on mortality were observed and there were no significant alterations in hematology or clinical chemistry parameters. Body weights were decreased and kidney weights were elevated in male rats at 300 and 900 ppm. Relative mean liver weights were elevated in males at 900 ppm, but no changes were noted in histopathology. There were no differences in weights of reproductive organs and no pathological changes. Under the conditions of this study, the No Observed Adverse Effect Concentration (NOAEC) was the highest concentration tested (900 ppm or approximately 5220 mg/m3.

Endpoint:
chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
8/1978 - 7/1984
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 452.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 452 (Chronic Toxicity Studies)
Deviations:
yes
Remarks:
Two dose levels used
GLP compliance:
not specified
Limit test:
no
Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals and environmental conditions:
Source - Charles River Breeding Laboratory, Wilmington, MA
Age at study start - 10 weeks
Food - available only during non-exposure periods
Water - ad libitum
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Details on inhalation exposure:
The generation of desired chamber concentrations of MCH was accomplished by metering liquid MCH directly into the chamber inlet air supply stream where vaporization was accomplished in sufficient air volume to prevent formation of an explosive vapor mixture. The liquid was delivered from a drum using 3-5 psig air pressure with dual regulators to prevent overpressurization. Delivery into the air supply line was metered and controlled with a glass flowmeter and 10 needle valve installed on a manifold from the storage drum and housed in an exhaust hood to prevent leakage into work areas. The stainless steel supply lines were wrapped with electrical heating tape to provide modest heat when necessary to prevent recondensation. Generation of MCH was started at a high rate and then adjusted to a steady rate to achieve 95% of the nominal chamber concentration within 15 minutes of daily start-up of animal exposures.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Air samples were continuously drawn from the chambers during animal exposures for analysis using a total hydrocarbon analyzer. Each pair of chambers with the same nominal concentration were sampled alternately on a 15 minute cycle with a single analyzer. Mean methylcyclohexane concentrations in animal exposure chambers were sampled on 243 separate days, mean measured concentration was 401.4+/- 4.5 ppm and 398.9 +/- 2.5 ppm for a nominal concentration of 400 ppm. Mean measured concentrations for the high exposure group (2000 ppm) was 2009+/-46.6 and 1998+/-52.4 ppm.
Duration of treatment / exposure:
12 months
Frequency of treatment:
6 hours/day, 5 days/week
Remarks:
Doses / Concentrations:
400 or 2000 ppm
Basis:
nominal conc.
No. of animals per sex per dose:
65/sex/concentration
Control animals:
not specified
Details on study design:
Rats were exposed to methylcyclohexane by the inhalation route in dome-shaped 840 cubic foot chambers for one year using an industrial work week schedule of 6 hours/day, 5 days/week with holidays and weekends off to simulate an industrial exposure regimen for man. Each exposure group consisted of 65 male and 65 female rats equally divided by sex.
Observations and examinations performed and frequency:
The animals used in this study were observed hourly during the one-year exposure phase. Rats were weighed at
biweekly intervals during exposure period.
Sacrifice and pathology:
Blood samples were drawn from rats only at necropsy following the one-year exposure. Clinical determinations were performed for a battery of tests including routine hematology, electrolytes, glucose, creatinine, bilirubin, serum protein, albumin, and three enzymes, SGPT, SGOT and alkaline phosphatase. Organ weight data were also obtained and evaluated for rats at sacrifice. All of the animals used in this study were necropsied at death with a battery of approximately 33 tissues sampled from each animal for histopathology examination following the protocol used by the National Cancer Institute.
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
Medullary mineralization and papillary hyperplasia was noted in male rat kidneys but not females which is consistent with male rat-associated hydrocarbon nephropathy.
Histopathological findings: neoplastic:
no effects observed
Details on results:
The only significant toxic effect of chronic exposure to inhaled methylcyclohexane found was renal change in male rats. The exposure related renal injury was not seen in female rats. Only male rats exposed to 2000 ppm MCH had significantly greater incidence of renal tubular dilation at exposure termination, and progression of renal pathology to papillary hyperplasia and medullary mineralization occurred only in the group exposed to the higher level. These findings are consistent with those produced by other paraffinic, cycloparaffinic, and alkylaromatic hydrocarbons. This syndrome now referred to as hydrocarbon nephropathy, is characterized by an increase in the incidence of hyalin droplets and of regenerative tubular epithelia in the cortex. In its most severe form the tubules at the corticomedullary junction become dilated and filled with proteinaceous debris with some necrosis.

Mean body weights for male rats (400 and 2000 ppm groups) was decreased throughout the study although there was no indication that these were statistically significant. No effects were noted with female rats.
Dose descriptor:
NOAEC
Effect level:
>= 2 000 ppm (nominal)
Sex:
male/female
Basis for effect level:
other: Kidney effects are not relevant in humans. There were no other adverse effects of chronic MCH exposure in rats
Critical effects observed:
not specified
Conclusions:
NOAEC for methylcyclohexane exposure in rats >= 2000 ppm
Executive summary:

Male and female F344 rats, female B6C3F1 mice, male Syrian golden hamsters and beagle dogs were exposed to methylcyclohexane (MCH) for 12 months at levels of 400 and 2000 ppm (approximately 1600 and 8000 mg/m3). Exposures were 6 hours/day, 5 days/week. The principal effect reported was progressive renal pathology in male rats. The authors of the study considered that the pathological effects as well as the gender- and species-specificity of these effects were consistent with the results reported in studies of other hydrocarbon solvents (i.e., α 2u-globulin-mediated effects). There were no effects on reproductive organs in any of the species.

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
short-term repeated dose toxicity: dermal
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
a short-term toxicity study does not need to be conducted because a reliable sub-chronic (90 days) or chronic toxicity study is available, conducted with an appropriate species, dosage, solvent and route of administration
Endpoint:
sub-chronic toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1997
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to or similar to guideline study OECD 411: GLP.
Justification for type of information:
The justification for read across is provided as an attachment in IUCLID Section 13.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 411 (Subchronic Dermal Toxicity: 90-Day Study)
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
Groups of 12 male and 12 female, individually housed, Sprague-Dawley rats aged 7-9 weeks were used. The males weighed 198-328 g and the females weighed 156-249 g at the initiation of the study.
Type of coverage:
semiocclusive
Vehicle:
other: unknown
Details on exposure:
Test material was applied at concentrations of 20, 40 or 60% (v/v) at a rate of 1 ml/kg/day to the shorn intrascapular region of the rats. This was equivalent to doses of test material of 165, 330 or 495 mg/kg/day. Dosing was continued daily for five consecutive days each week, five days a week for 13 weeks. In addition a group of 12 male and 12 female rats of similar age were administered mineral oil at a dose rate of 1 ml/kg/day; these animals served as vehicle controls. An additional 12 rats/sex/group in the vehicle controls and high dose group were maintained for a 4-week recovery period following dosing for 13 weeks. All animals were fitted with collars to prevent ingestion and these were removed six hours after dosing and any residual test or control material was wiped from the skin. Animals were observed for clinical signs prior to dosing and 1, 6 and 24 hours after the first dose. Subsequently, observations were made prior to each dose being applied. Prior to the administration of each dose, the treated skin site was evaluated for dermal irritation using the Draize scoring method. Body weights were recorded prior to the first dose and weekly thereafter. An ophthalmic examination was conducted on each rat prior to application of the first dose and again prior to sacrifice at the end of the study. During the week prior to the first dose, each rat was subjected to a functional observation battery (FOB). The FOB was conducted again 1 and 24 hours after the first dose and at 7 and 14 days. During the study, the FOB, motor activity and startle response testing were conducted on all rats at weeks 4, 8 and 12. [The details of the FOB, the test for startle response test and the test for motor activity are given in detail in the laboratory report but are not included here]. At the 14 week necropsy, blood samples were collected from 12 animals/sex/group and at the week 18 necropsy from the recovery rats (vehicle and high dose groups).
Duration of treatment / exposure:
This was equivalent to doses of test material of 165, 330 or 495 mg/kg/day. Dosing was continued daily for five consecutive days each week, five days a week for 13 weeks.
Frequency of treatment:
This was equivalent to doses of test material of 165, 330 or 495 mg/kg/day. Dosing was continued daily for five consecutive days each week, five days a week for 13 weeks.
Remarks:
Doses / Concentrations:
0, 165, 330 or 495 mg/kg/day
Basis:
nominal per unit body weight
No. of animals per sex per dose:
Groups of 12 male and 12 female per dose
Control animals:
yes, concurrent vehicle
Details on study design:
Groups of 12 male and 12 female, individually housed, Sprague-Dawley rats aged 7-9 weeks were used. The males weighed 198-328 g and the females weighed 156-249 g at the initiation of the study.
Test material was applied at concentrations of 20, 40 or 60% (v/v) at a rate of 1 ml/kg/day to the shorn intrascapular region of the rats. This was equivalent to doses of test material of 165, 330 or 495 mg/kg/day. Dosing was continued daily for five consecutive days each week, five days a week for 13 weeks. In addition a group of 12 male and 12 female rats of similar age were administered mineral oil at a dose rate of 1 ml/kg/day; these animals served as vehicle controls. An additional 12 rats/sex/group in the vehicle controls and high dose group were maintained for a 4-week recovery period following dosing for 13 weeks. All animals were fitted with collars to prevent ingestion and these were removed six hours after dosing and any residual test or control material was wiped from the skin. Animals were observed for clinical signs prior to dosing and 1, 6 and 24 hours after the first dose. Subsequently, observations were made prior to each dose being applied. Prior to the administration of each dose, the treated skin site was evaluated for dermal irritation using the Draize scoring method. Body weights were recorded prior to the first dose and weekly thereafter. An ophthalmic examination was conducted on each rat prior to application of the first dose and again prior to sacrifice at the end of the study. During the week prior to the first dose, each rat was subjected to a functional observation battery (FOB). The FOB was conducted again 1 and 24 hours after the first dose and at 7 and 14 days. During the study, the FOB, motor activity and startle response testing was conducted on all rats at weeks 4, 8 and 12. [The details of the FOB, the test for startle response test and the test for motor activity are given in detail in the laboratory report but are not included here]. At the 14 week necropsy, blood samples were collected from 12 animals/sex/group and at the week 18 necropsy from the recovery rats (vehicle and high dose groups).

The following hematological and clinical chemical parameters were measured.
HEMATOLOGY:
Erythrocyte count
Hemoglobin
Hematocrit
Mean corpuscular volume
Mean corpuscular hemoglobin
Mean corpuscular hemoglobin concentration
Platelet count
Reticulocyte count
Total leukocyte count
Differential leukocyte count
Morphological examination of erythrocytes and platelets Coagulation determinations (prothrombin time & activated partial thromboplastin time) were also carried out on six animals from each group at week 14 and from the recovery groups at the week 18 necropsy.

CLINICAL CHEMISTRY
Blood urea nitrogen,
Creatinine,
Serum aspartate aminotransferase,
Serum alanine aminotransferase,
Alkaline phosphatase,
Lactate dehydrogenase,
Sorbitol dehydrogenase,
Gamma glutamyl transferase,
Creatinine kinase,
Serum glucose
Total, direct and indirect bilirubin
Total protein
Albumin
Calcium
Phosphorus
Sodium
Potassium
Chloride
A complete necropsy was performed on six rats/sex/group following 13 weeks dosing, and on 6 rats/sex/group of the recovery animals (high dose and controls) at week 18. A limited necropsy was performed on the remaining six animals and their organs were not weighed (see below). Each full necropsy included an examination of the external surface of the body, all orifices, cranial, thoracic, abdominal and pelvic cavities and their contents. Gross observations were recorded and the following organs were weighed: Adrenal glands, brain, epididymides, heart, kidneys, liver, ovaries, prostate, spleen, testes, thymus and uterus.

The following tissues were collected, processed and then examined microscopically.
Adrenal glands,
Nose (nasal cavity & turbinates),
Animal identification,
Ovaries,
Bone marrow (from sternum),
Oviducts,
Brain,
Pancreas,
Epididymides,
Parathyroid glands,
Esophagus,
Pituitary gland,
Exorbital lacrimal glands,
Prostate Eyes with optic nerve,
Salivary glands,
Femur (incl. articular surface),
Seminal vesicles,
Gross lesions Skin (application site),
Harderian gland,
Skin (inguinal),
Heart and aorta,
Spinal cord (3 levels),
Intestine (3 levels),
Spleen,
Kidneys,
Stomach,
Larynx and pharynx,
Testes,
Liver,
Thymus,
Lungs with mainstream bronchi,
Thyroid gland,
Lymph nodes (mandibular/mesenteric),
Urinary bladder,
Mammary glands with adjacent skin,
Uterus Muscle (thigh),
Vagina Nerve (sciatic).

The remaining six rats of each group were anesthetized with an intraperitoneal injection of Pentothal ® and transcardially perfused in-situ using 10% neutral-buffered formalin and given a limited necropsy. For these rats, no organs were weighed and the following tissues were collected: Head/skull, Sural nerve, Brain, Tibial nerve, Spinal cord, Gross lesions, Sciatic nerve.

The following tissues were examined microscopically in these animals: Brain (forebrain, cerebrum, midbrain, cerebellum, pons and medulla obligata), Gasserian ganglia, Dorsal root ganglia, Dorsal and ventral root fibers, Sural nerve, Tibial nerve, Spinal cord (cervical and lumbar areas), and Sciatic nerve.
Observations and examinations performed and frequency:
Groups of 12 male and 12 female, individually housed, Sprague-Dawley rats aged 7-9 weeks were used. The males weighed 198-328 g and the females weighed 156-249 g at the initiation of the study.
Test material was applied at concentrations of 20, 40 or 60% (v/v) at a rate of 1 ml/kg/day to the shorn intrascapular region of the rats. This was equivalent to doses of test material of 165, 330 or 495 mg/kg/day. Dosing was continued daily for five consecutive days each week, five days a week for 13 weeks. In addition a group of 12 male and 12 female rats of similar age were administered mineral oil at a dose rate of 1 ml/kg/day; these animals served as vehicle controls. An additional 12 rats/sex/group in the vehicle controls and high dose group were maintained for a 4-week recovery period following dosing for 13 weeks. All animals were fitted with collars to prevent ingestion and these were removed six hours after dosing and any residual test or control material was wiped from the skin. Animals were observed for clinical signs prior to dosing and 1, 6 and 24 hours after the first dose. Subsequently, observations were made prior to each dose being applied. Prior to the administration of each dose, the treated skin site was evaluated for dermal irritation using the Draize scoring method. Body weights were recorded prior to the first dose and weekly thereafter. An ophthalmic examination was conducted on each rat prior to application of the first dose and again prior to sacrifice at the end of the study. During the week prior to the first dose, each rat was subjected to a functional observation battery (FOB). The FOB was conducted again 1 and 24 hours after the first dose and at 7 and 14 days. During the study, the FOB, motor activity and startle response testing was conducted on all rats at weeks 4, 8 and 12. [The details of the FOB, the test for startle response test and the test for motor activity are given in detail in the laboratory report but are not included here].
Sacrifice and pathology:
At the 14 week necropsy, blood samples were collected from 12 animals/sex/group and at the week 18 necropsy from the recovery rats (vehicle and high dose groups).

The following hematological and clinical chemical parameters were measured.
HEMATOLOGY:
Erythrocyte count
Hemoglobin
Hematocrit
Mean corpuscular volume
Mean corpuscular hemoglobin
Mean corpuscular hemoglobin concentration
Platelet count
Reticulocyte count
Total leukocyte count
Differential leukocyte count
Morphological examination of erythrocytes and platelets Coagulation determinations (prothrombin time & activated partial thromboplastin time) were also carried out on six animals from each group at week 14 and from the recovery groups at the week 18 necropsy.

CLINICAL CHEMISTRY
Blood urea nitrogen,
Creatinine,
Serum aspartate aminotransferase,
Serum alanine aminotransferase,
Alkaline phosphatase,
Lactate dehydrogenase,
Sorbitol dehydrogenase,
Gamma glutamyl transferase,
Creatinine kinase,
Serum glucose
Total, direct and indirect bilirubin
Total protein
Albumin
Calcium
Phosphorus
Sodium
Potassium
Chloride
A complete necropsy was performed on six rats/sex/group following 13 weeks dosing, and on 6 rats/sex/group of the recovery animals (high dose and controls) at week 18. A limited necropsy was performed on the remaining six animals and their organs were not weighed (see below). Each full necropsy included an examination of the external surface of the body, all orifices, cranial, thoracic, abdominal and pelvic cavities and their contents. Gross observations were recorded and the following organs were weighed: Adrenal glands, brain, epididymides, heart, kidneys, liver, ovaries, prostate, spleen, testes, thymus and uterus.

The following tissues were collected, processed and then examined microscopically.
Adrenal glands,
Nose (nasal cavity & turbinates),
Ovaries,
Bone marrow (from sternum),
Oviducts,
Brain,
Pancreas,
Epididymides,
Parathyroid glands,
Esophagus,
Pituitary gland,
Exorbital lacrimal glands,
Prostate Eyes with optic nerve,
Salivary glands,
Femur (incl. articular surface),
Seminal vesicles,
Gross lesions Skin (application site),
Harderian gland,
Skin (inguinal),
Heart and aorta,
Spinal cord (3 levels),
Intestine (3 levels),
Spleen,
Kidneys,
Stomach,
Larynx and pharynx,
Testes,
Liver,
Thymus,
Lungs with mainstream bronchi,
Thyroid gland,
Lymph nodes (mandibular/mesenteric),
Urinary bladder,
Mammary glands with adjacent skin,
Uterus Muscle (thigh),
Vagina Nerve (sciatic).

The remaining six rats of each group were anesthetized with an intraperitoneal injection of Pentothal ® and transcardially perfused in-situ using 10% neutral-buffered formalin and given a limited necropsy. For these rats, no organs were weighed and the following tissues were collected: Head/skull, Sural nerve, Brain, Tibial nerve, Spinal cord, Gross lesions, Sciatic nerve.

The following tissues were examined microscopically in these animals: Brain (forebrain, cerebrum, midbrain, cerebellum, pons and medulla obligata), Gasserian ganglia, Dorsal root ganglia, Dorsal and ventral root fibers, Sural nerve, Tibial nerve, Spinal cord (cervical and lumbar areas), and Sciatic nerve.
Statistics:
Statistics Normally-distributed in-life data (parametric) were analyzed for test substance effects by analysis of variance and pairwise comparisons made between groups using Dunnett's test. Nonparametric data (non-homogeneous as determined by Bartlett's test) were analyzed using a modified t-test. Statistical significance was reported at the P < 0.05 level. Statistical analyses of neurobehavior data (FOB and motor activity) are described in the results section.
Clinical signs:
no effects observed
Dermal irritation:
effects observed, treatment-related
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
There were no test substance-related effects on survival, clinical observations (apart from skin irritation), neurobehavioral signs or ophthalmological findings. The only clinical observations during the study were related to skin irritation at the application site. There was a generally dose-related increase in the incidence and severity of erythema, edema, epidermal scaling, scab formation, thickening of the skin and ulceration at the treated site. Males seemed to be more sensitive than females. The FOB screen did not demonstrate any substance-related effects. The areas monitored were: behavioral parameters, including autonomic, muscle tone and equilibrium, sensorimotor responses, central nervous system. In addition the test substance had little effect on motor activity or startle response. Growth rates were unaffected by treatment. At necropsy no substance-related observations were made for males in any group. In the females there was a suggestion of a possible treatment- related effect which occurred in 7 rats across all groups and consisted of skin crusts or ulceration at the site of application of test material. Hematological and serum clinical parameters were unaffected by treatment. The only organ weight effects noted were an increase in spleen/body weight and spleen/brain weight ratios in the high dose group females at the 13 week necropsy and an increase in absolute spleen weight in the same dose group females after the 4 weeks recovery period. Since there were no associated microscopic or clinical chemical findings, these differences were not considered to be of biological relevance. There were no treatment-related microscopic changes in the tissues examined with the exception of the findings in the skin. The skin observations were minimal in nature with a severity score less than 1 on a 1 [low] to 4 [severe] scale. The findings included acanthosis, ulceration, parakeratosis, chronic active inflammation and hyperkeratosis. The males were affected at all doses, however, the effects indicated very little irritation. Recovery group animals revealed complete recovery in the females and minimal hyperkeratosis in the high dose group males. No effects were found in the animals subjected to a detailed neuropathological examination.
Dose descriptor:
NOAEL
Remarks:
Systemic
Effect level:
> 495 mg/kg bw/day
Sex:
male/female
Basis for effect level:
other: No systemic or neurological effects were noted in the study
Critical effects observed:
not specified
Conclusions:
There were no systemic or neurological effects noted at any of the tested doses. The systemic NOAEL was >495 mg/kg/day.
Executive summary:

Test material was applied at concentrations of 165, 330 or 495 mg/kg/day. Dosing was continued daily for five consecutive days each week, five days a week for 13 weeks. In addition a group of 12 male and 12 female rats of similar age was administered mineral oil as vehicle controls and an additional high dose group was maintained for a 4-week recovery period following dosing for 13 weeks. At the 14 week necropsy, blood samples were collected from 12 animals/sex/group and at the week 18 necropsy from the recovery rats (vehicle and high dose groups). There were no systemic or neurological effects noted at any of the tested doses. The systemic NOAEL was >495 mg/kg/day.

Endpoint conclusion
Dose descriptor:
NOAEL
495 mg/kg bw/day
Study duration:
subchronic
Species:
rat

Additional information

Oral: C14-20 Aliphatics (≤2% aromatic) are expected to have a low order of repeated dose toxicity by the oral route of exposure. Two read-across studies from the structurally analogous test materials "Hydrocarbons C12-C16, n-alkanes, isoalkanes, cyclics, <2% aromatics" and "Hydrocarbons, C10 -C13, n-alkanes, isoalkanes, cyclics, < 2% aromatics" were analysed. All tests were performed in a manner similar or equivalent to currently established OECD guidelines. The systemic NOAEL were determined to be higher than 1000 and 5000 mg/kg/day, respectively.

 

Dermal: C14-20 Aliphatics (≤2% aromatic) are expected to have a low order of repeated dose toxicity by the dermal route of exposure. No study was located for the test substance C14-C20 aliphatics, <2% aromatics, however, available read-across data from the structurally analogous test material hydrodesulfurized kerosene was analysed. All tests were performed in a manner similar or equivalent to currently established OECD guidelines. In a repeated dose study where hydrodesulfurized kerosene was administered via semi-occlusive patch, the systemic NOAEL was determined to be 495 mg/kg/day, which was the highest dose tested.

Justification for classification or non-classification

These findings do not warrant the classification of C14-20 Aliphatics (≤2% aromatic) as a repeated dose toxicant under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP) or under the Directive 67/548/EEC for dangerous substances.