Pyridine, alkyl derivs.

Endpoint summary

Description of key information

Two studies are available on repeated dose toxicity, a sub-acute oral toxicity study and a sub-chronic inhalation toxicity study. Determination of sub-acute oral toxicity was carried out with 5-ethyl-2-methylpyridine (MEP, CAS no.: 104-90-5, EC no.: 203-250-0). Determination of acute inhalation toxicity was carried out with 2-picoline (CAS no.: 109-06-8, EC no.: 203-643-7). The read-across between both substances and Pyridine, alkyl derivs. is justified. A study on dermal repeated dose toxicity was waived. 
The sub-acute oral toxicity study was carried out according to EU Method B.7 and OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents). The test item was administered per gavage to groups of six rats, male and female at dose levels of 30, 95 and 300 mg/kg bw/day. The NOAEL was determined to be 30 mg/kg bw/day. The LOAEL was determined at 95 mg/kg bw/day with slight clinical effects and minimal renal lesions in the male rats. At 300 mg/kg bw/day moderate clinical and clinicopathological effects and moderate renal lesions in male rats were found.
The sub-chronic inhalation toxicity study revealed no signs of toxicity at any treatment level at any time. There were no statistically or toxicologically significant differences in the body weights, between organs, in hematology, clinical chemistry, urine analysis, or histopathologic examinations between treatment and control groups that were considered to be treatment-related. No grossly visible lesions could be attributed to test substance exposure. The NOAEC (NOEC) was determined to be 100 ppm equivalent to 0.38 mg/L. No threshold for systemic toxicity was established. 
A dermal repeated dose toxicity study was waived. A NOAEL long-term, dermal of 30 mg/kg bw/day was calculated from the NOAEL long-term, oral of 30 mg/kg bw/day, assuming 100 % resorption through the skin.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Read-across from supporting substance Substance: 5-ethyl-2-methylpyridine (MEP) CAS no.: 104-90-5 EC no.: 203-250-0 Pyridine, alkyl derivatives is a substance of Unknown or Variable Composition, Complex Reaction Products, or Biological Materials (UVCB, subtype 2). The substance is not a discrete chemical, but characterized by a variety of structures. The substance 2-ethyl-4-methylpyridine (CAS no. 26091-11-2) and its isomer 5-ethyl-2-methylpyridine (MEP, CAS no. 104-90-5) were selected as representative model structures. The read-across is based on the hypothesis that source and target substance have similar properties, because they share a common functional group, common precursors and the likelihood of common breakdown products via physical and biological processes, which result in structurally similar chemicals. Please see the attached read-across justification for details.

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga, Sulzfeld, BRD
- Age at study initiation: 4 weeks / period
- Weight at study initiation: 90 - 100 g at start of acclimatization
- Fasting period before study: None
- Housing: Makrolon type II
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: At least 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 °C +/- 20 °C
- Humidity (%): 55 % +/- 10 %
- Air changes (per hr): 15 - 20 times/hour
- Photoperiod (hrs dark / hrs light): 12/12 hours light-dark cycle

IN-LIFE DATES: From: 24.09.1987 To: 22.10.1987

Route of administration:

oral: gavage

Vehicle:

other: 1.2-propylene glycol (7 parts) + double distilled water (11 parts)

Details on oral exposure:

VEHICLE
- Justification for use and choice of vehicle (if other than water):
- Concentration in vehicle: 3, 9.5 and 30 mg/mL
- Amount of vehicle (if gavage): 1 mL/100 g bw

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analytical method: UV; identity proven by UV-spectra

Duration of treatment / exposure:

28 days, 7 days per week

Frequency of treatment:

once daily

Remarks:

Doses / Concentrations:
30, 95, 300 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

6 animals per dose group.

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Range finding study
- Rationale for animal assignment (if not random): Random
- Rationale for selecting satellite groups: None.
- Post-exposure recovery period in satellite groups: None.
- Section schedule rationale (if not random): Random

Positive control:

None.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily on 7 days/week.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Twice daily on 7 days/week.

BODY WEIGHT: Yes
- Time schedule for examinations: Body weight was recorded daily, starting at pretreatment period and reported weekly.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: 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: No

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At week 4 of treatment blood samples for hematology and blood chemistry were obtained from the right orbital vein plexus and collected into EDTA tubes (hematology) and lithium - heparin tubes (blood chemistry). Food was removed overnight prior to blood collection. Blood samples were collected between 7.00 and 9.00 a.m. (24 hours after compound administration) to prevent chronobiologic variations.
- Anaesthetic used for blood collection: No data
- Animals fasted: Yes, overnight.
- How many animals: 6 per control and dose group
- Parameters checked in table were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: see hematology above
- Animals fasted: Yes
- How many animals: 6 per control and dose group
- Parameters checked in table were examined.

URINALYSIS: No, investigation was not indicated by clinical signs

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (see below for details)
HISTOPATHOLOGY: Yes (see below for details)

Statistics:

Routine evaluation of the data was done by:
* Student's t-test (t) +)
Normal distributed values, single treatment groups are compared against the control group.
* U-test (U) +)
In not normal distributed values the U-test of Wilcoxon, Mann and Whitney was employed to compare two autonomous random samples.
* William's test (Wi) ++)
The control group was compared with treatment groups of constant increasing or decreasing dosage, to determine the lowest dosage, where a significant difference was apparent. The method used therefore was the Williams test (Trend test).
* Bartlett's test (Ba) +)
This test checks the homogeneity of variance in normal distributed data groups.
* Global test (Kr) +)
In biological data mostly a sufficient normal distribution of values cannot be assumed. Therefore the H-test of Kruskal and Wallis is applied to compare several autonomous random samples.

+) SACHS, L: "Angewandte Statistik", Springer, Berlin, 6. Auflage, 1984

++) WILLIAMS, D.A.: 'The comparison of several dose levels with a zero dose control" Biometrics, 28, (1972): 519 - 531

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

At weeks 2, 3 and 4 of treatment salivation was found at doses 95 and 300 mg/kg bw/day, in both sexes. None of the animals died during the study.

Mortality:

mortality observed, treatment-related

Description (incidence):

At weeks 2, 3 and 4 of treatment salivation was found at doses 95 and 300 mg/kg bw/day, in both sexes. None of the animals died during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

At dose 300 mg/kg bw/day, group males, body weight gain was lower in comparison to control (statistically significant at days 8 and 15 of treatment and at termination).

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

At dose 300 mg/kg bw/day, group males, food consumption was significantly lower in comparison to control at week (p < 0.05) of treatment.

Food efficiency:

no effects observed

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Erythrocytes and hematocrit were significantly different to controls in high dose females.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

MCV, MCH and MCHC were significantly different to controls in high dose females.

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):

Lesions were seen either in both control and treated rats or occurred at a very low incidence and were considered not to be due to treatment with the test item.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Mottled kidneys were present in high dose males. Other leasions were considered chance occurence.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Nephropathy was observed in males animales. Other leasions were not considered treatment related.

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
At weeks 2, 3 and 4 of treatment salivation was found at doses 95 and 300 mg/kg bw/day, in both sexes. None of the animals died during the study.

BODY WEIGHT AND WEIGHT GAIN
At dose 300 mg/kg bw/day, group males, body weight gain was lower in comparison to control (statistically significant at days 8 and 15 of treatment and at termination). No difference to control was found in females.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
At dose 300 mg/kg bw/day, group males, food consumption was significantly lower in comparison to control at week (p < 0.05) of treatment. In the other dose groups food consumption was similar to control.

FOOD EFFICIENCY
At dose 300 mg/kg bw/day, group males, mean food utilization was slightly lower in comparison to control.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)
Not examined.

OPHTHALMOSCOPIC EXAMINATION
Not examined.

HAEMATOLOGY
Parameters determined:
RBC
Hemoglobin
Hematocrit
MCV
MCH
MCHC
Reticulocytes
WBC (total and differential)
Platelet count

Erythrocytes and Hematocrit:
The number of erythrocytes was significantly higher at dose 30 mg/kg bw/day, group males, and lower at dose 300 mg/kg bw/day, group females, in comparison to control. The increase at dose 30 mg/kg bw/day is considered not to be related to treatment (lack of dose-dependence; historical data).
At doses 30 and 300 mg/kg bw/day, group females, hematocrit values were significantly lower and at dose 30 mg/kg bw/day, group males, hematocrit was significantly higher relative to control. The changes at dose 30 mg/kg bw/day in both sexes are considered not to be treatment related (historical data).
MCV, MCH and MCHC:
At dose 95 mg/kg bw/day, group females, MCV was significantly lower in comparison to control, but considered not to be treatment related (lack of dose-dependence, historical data).
At dose 300 mg/kg bw/day, group females, MCH was significantly higher in comparison to control. At dose 30 mg/kg bw/day, group males, MCH was significantly lower in comparison to control, but considered not to be treatment related (lack of dose dependence, historical data).
At dose 300 mg/kg bw/day, group females, MCHC was significantly higher relative to the control. At doses 30, 95 and 300 mg/kg bw/day, group males, values were significantly lower in comparison to control, but considered not to be treatment related (lack of dose-dependence, historical data).

CLINICAL CHEMISTRY
Parameters determined:
Glucose
Urea
Creatinine
Total bilirubin
Total cholesterol
ASAT
ALAT
LDH
GGT
AP
Total protein
Inorganic phosphorus
Page 7 of 221
Chloride
Sodium
Potassium
Calcium
Protein-electrophoresis
(absolute and relative)

Urea:
At dose 300 mg/kg bw/day, group males, significantly higher in comparison to control.
Creatinine:
At doses 95 and 300 mg/kg bw/day, group males, higher relative to the control, but statistically significant at dose 95 mg/kg bw/day only.
ASAT:
At dose 300 mg/kg bw/day, group males, significantly higher in comparison to control.
ALANIN-AMINOTRANSFERASE:
At dose 95 mg/kg bw/day, group males, ALA T activity was markedly increased in 1/6 animals, but no statistically significant difference to control was found in group mean values.
LDH:
At dose 95 mg/kg bw, group males, LDH activity was markedly increased in one animal. Also in one female of control LDH activity was increased.
Chloride:
At dose 300 mg/kg bw/day, group females, significantly lower in comparison to control.
Potassium:
At dose 95 mg/kg bw/day, group males, significantly higher in comparison to control, which might be treatment related, but the potassium concentration at dose 300 mg/kg bw was not significantly higher than in the control group.
ALPHA 1 - GLOBULINS (Fraction 2):
Absolute and relative values were significantly low rat dose 95 mg/kg bw/day, group females, and dose 300 mg/kg bw/day, group males, in comparison to control. At dose 30 mg/kg bw/day, group males, absolute values were significantly lower relative to control, but considered not to be treatment related (lack of dose-dependence, historical data).
ALPHA 1 - GLOBULINS (Fraction 3):
Absolute and relative values at dose 30 mg/kg bw/day, in both sexes and at dose 300 mg/kg bw/day, group females, were significantly higher in comparison to control. Additionally a significant increase relative to the control was seen in relative values at dose 95 mg/kg bw/day, group females. The changes were considered not to be treatment related (lack of dose-dependence, historical data).
BETA - GLOBULINS (Fraction 4):
Relative values at doses 95 and 300 mg/kg bw/day, group males, were significantly higher in comparison to control. No difference to control was seen in absolute values. Because of historical data and the lack of a clear dose-dependence the changes might be not treatment related.

URINALYSIS
CLINICAL SIGNS AND MORTALITY
At weeks 2, 3 and 4 of treatment salivation was found at doses 95 and 300 mg/kg bw/day, in both sexes. None of the animals died during the study.

BODY WEIGHT AND WEIGHT GAIN
At dose 300 mg/kg bw/day, group males, body weight gain was lower in comparison to control (statistically significant at days 8 and 15 of treatment and at termination). No difference to control was found in females.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
At dose 300 mg/kg bw/day, group males, food consumption was significantly lower in comparison to control at week (p < 0.05) of treatment. In the other dose groups food consumption was similar to control.

FOOD EFFICIENCY
At dose 300 mg/kg bw/day, group males, mean food utilization was slightly lower in comparison to control.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)
Not examined.

OPHTHALMOSCOPIC EXAMINATION
Not examined.

HAEMATOLOGY
Parameters determined:
RBC
Hemoglobin
Hematocrit
MCV
MCH
MCHC
Reticulocytes
WBC (total and differential)
Platelet count

Erythrocytes and Hematocrit:
The number of erythrocytes was significantly higher at dose 30 mg/kg bw/day, group males, and lower at dose 300 mg/kg bw/day, group females, in comparison to control. The increase at dose 30 mg/kg bw/day is considered not to be related to treatment (lack of dose-dependence; historical data).
At doses 30 and 300 mg/kg bw/day, group females, hematocrit values were significantly lower and at dose 30 mg/kg bw/day, group males, hematocrit was significantly higher relative to control. The changes at dose 30 mg/kg bw/day in both sexes are considered not to be treatment related (historical data).
MCV, MCH and MCHC:
At dose 95 mg/kg bw/day, group females, MCV was significantly lower in comparison to control, but considered not to be treatment related (lack of dose-dependence, historical data).
At dose 300 mg/kg bw/day, group females, MCH was significantly higher in comparison to control. At dose 30 mg/kg bw/day, group males, MCH was significantly lower in comparison to control, but considered not to be treatment related (lack of dose dependence, historical data).
At dose 300 mg/kg bw/day, group females, MCHC was significantly higher relative to the control. At doses 30, 95 and 300 mg/kg bw/day, group males, values were significantly lower in comparison to control, but considered not to be treatment related (lack of dose-dependence, historical data).

CLINICAL CHEMISTRY
Parameters determined:
Glucose
Urea
Creatinine
Total bilirubin
Total cholesterol
ASAT
ALAT
LDH
GGT
AP
Total protein
Inorganic phosphorus
Page 7 of 221
Chloride
Sodium
Potassium
Calcium
Protein-electrophoresis
(absolute and relative)

Urea:
At dose 300 mg/kg bw/day, group males, significantly higher in comparison to control.
Creatinine:
At doses 95 and 300 mg/kg bw/day, group males, higher relative to the control, but statistically significant at dose 95 mg/kg bw/day only.
ASAT:
At dose 300 mg/kg bw/day, group males, significantly higher in comparison to control.
ALANIN-AMINOTRANSFERASE:
At dose 95 mg/kg bw/day, group males, ALA T activity was markedly increased in 1/6 animals, but no statistically significant difference to control was found in group mean values.
LDH:
At dose 95 mg/kg bw, group males, LDH activity was markedly increased in one animal. Also in one female of control LDH activity was increased.
Chloride:
At dose 300 mg/kg bw/day, group females, significantly lower in comparison to control.
Potassium:
At dose 95 mg/kg bw/day, group males, significantly higher in comparison to control, which might be treatment related, but the potassium concentration at dose 300 mg/kg bw was not significantly higher than in the control group.
ALPHA 1 - GLOBULINS (Fraction 2):
Absolute and relative values were significantly low rat dose 95 mg/kg bw/day, group females, and dose 300 mg/kg bw/day, group males, in comparison to control. At dose 30 mg/kg bw/day, group males, absolute values were significantly lower relative to control, but considered not to be treatment related (lack of dose-dependence, historical data).
ALPHA 1 - GLOBULINS (Fraction 3):
Absolute and relative values at dose 30 mg/kg bw/day, in both sexes and at dose 300 mg/kg bw/day, group females, were significantly higher in comparison to control. Additionally a significant increase relative to the control was seen in relative values at dose 95 mg/kg bw/day, group females. The changes were considered not to be treatment related (lack of dose-dependence, historical data).
BETA - GLOBULINS (Fraction 4):
Relative values at doses 95 and 300 mg/kg bw/day, group males, were significantly higher in comparison to control. No difference to control was seen in absolute values. Because of historical data and the lack of a clear dose-dependence the changes might be not treatment related.

URINALYSIS
Investigation was not indicated by clinical signs.

NEUROBEHAVIOUR
Not examined.

ORGAN WEIGHTS
Organs weighed:
Adrenals
Brain
Heart
Kidneys
Liver
Spleen
Testes

Brain:
Relative organ weight at dose 300 mg/kg bw/day, group males, was significantly higher in comparison to control.
Heart:
Absolute organ weight at dose 30 mg/kg bw/day, group females, was significantly lower in comparison to control.
Kidneys:
Relative organ weight at dose 300 mg/kg bw/day, group males, was significantly higher relative to control.
Liver:
Relative organ weight at doses 95 mg/kg bw/day, group males, and 300 mg/kg bw/day in both sexes was significantly higher in comparison to control. Absolute organ weight was significantly higher at dose 95 mg/kg bw/day, group males.
Spleen:
Absolute organ weight at dose 300 mg/kg bw/day, group males, was significantly (p < 0.05) lower in comparison to control.
Testes:
Relative organ weight at dose 300 mg/kg bw/day, was significantly higher relative to the control.

GROSS PATHOLOGY
Mottled kidneys were present in 5/6 male rats at dose 300 mg/kg bw/day, but not in the other treated or control groups. Other gross lesions (red mucosa of stomach, enlarged or swollen liver) occurred in a non-dose related manner and were found to be due to chance occurrence.

HISTOPATHOLOGY: NON-NEOPLASTIC
The principal treatment related lesion was nephropathy which was seen in the male rats only. Nephropathy was slight to marked and characterized by swelling of the renal epithelial cells with occasional vacuolation and increased eosinophilia due to the presence of intracytoplasmic eosinophilic granules and hyaline droplets principally in the renal cortex.
Nephropathy was more severe at dose 300 mg/kg bw/day (marked nephropathy) than in the other treated groups but was more frequent at dose 95 mg/kg bw/day (5/6 rats) than at 300 mg/kg bw/day (2/6 rats). Slight nephropathy was also seen in one rat each of the control and at dose 30 mg/kg bw/day. Other renal lesions, as tubular casts, tubular basophilia and dilation, hydronephrosis and congestion were one time occurrences and were considered not to be treatment-related.
Other lesions were seen in the heart (myocarditis and myopathy), spleen (congestion), stomach (dilated crypts and degeneration), liver (microgranuloma) and adrenal (cytoplasmic vacuolation). These lesions were seen either in both control and treated rats or occurred at a very low incidence and were considered not to be due to treatment with the test item.

HISTOPATHOLOGY: NEOPLASTIC (if applicable)
Not applicable.

HISTORICAL CONTROL DATA (if applicable)
Not applicable.

OTHER FINDINGS
None.


NEUROBEHAVIOUR
Not examined.

ORGAN WEIGHTS
Organs weighed:
Adrenals
Brain
Heart
Kidneys
Liver
Spleen
Testes

Brain:
Relative organ weight at dose 300 mg/kg bw/day, group males, was significantly higher in comparison to control.
Heart:
Absolute organ weight at dose 30 mg/kg bw/day, group females, was significantly lower in comparison to control.
Kidneys:
Relative organ weight at dose 300 mg/kg bw/day, group males, was significantly higher relative to control.
Liver:
Relative organ weight at doses 95 mg/kg bw/day, group males, and 300 mg/kg bw/day in both sexes was significantly higher in comparison to control. Absolute organ weight was significantly higher at dose 95 mg/kg bw/day, group males.
Spleen:
Absolute organ weight at dose 300 mg/kg bw/day, group males, was significantly (p < 0.05) lower in comparison to control.
Testes:
Relative organ weight at dose 300 mg/kg bw/day, was significantly higher relative to the control.

GROSS PATHOLOGY
Mottled kidneys were present in 5/6 male rats at dose 300 mg/kg bw/day, but not in the other treated or control groups. Other gross lesions (red mucosa of stomach, enlarged or swollen liver) occurred in a non-dose related manner and were found to be due to chance occurrence.

HISTOPATHOLOGY: NON-NEOPLASTIC
The principal treatment related lesion was nephropathy which was seen in the male rats only. Nephropathy was slight to marked and characterized by swelling of the renal epithelial cells with occasional vacuolation and increased eosinophilia due to the presence of intracytoplasmic eosinophilic granules and hyaline droplets principally in the renal cortex.
Nephropathy was more severe at dose 300 mg/kg bw/day (marked nephropathy) than in the other treated groups but was more frequent at dose 95 mg/kg bw/day (5/6 rats) than at 300 mg/kg bw/day (2/6 rats). Slight nephropathy was also seen in one rat each of the control and at dose 30 mg/kg bw/day. Other renal lesions, as tubular casts, tubular basophilia and dilation, hydronephrosis and congestion were one time occurrences and were considered not to be treatment-related.
Other lesions were seen in the heart (myocarditis and myopathy), spleen (congestion), stomach (dilated crypts and degeneration), liver (microgranuloma)and adrenal (cytoplasmic vacuolation). These lesions were seen either in both control and treated rats or occurred at a very low incidence and were considered not to be due to treatment with the test item.

HISTOPATHOLOGY: NEOPLASTIC (if applicable)
Not applicable.

HISTORICAL CONTROL DATA (if applicable)
Not applicable.

OTHER FINDINGS
None.

Dose descriptor:

NOAEL

Effect level:

30 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No treatment related effects were found at dose 30 mg/kg bw/day.

Dose descriptor:

LOAEL

Effect level:

95 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: The administration of 95 mg/kg bw/day resulted in slight clinical effects and minimal renal lesions in the male rats.

Critical effects observed:

not specified

Conclusions:

In this sub-acute oral toxicity study the test item was administered to groups of 6 rats (Sprague-Dawley, Cd: CDR (SD) BR), male and female by gavage] at dose levels of 30, 95 and 300 mg/kg bw/day. Nephropathy in the male rats at doses 95 and 300 mg/kg bw/day was the principal treatment effect following administration of the test item. The lesion might be similar to the protein nephropathy induced by xenobiotics in the male rat. Alden (1986) reported that several chemicals specifically increase significantly alpha-2u globulin accumulation in the proximal convoluted tubular epithelium of the male rat as a primary acute toxicological effect, although it was demonstrated that the spontaneous hyaline droplet in the otherwise normal male rat-kidney consists exclusively of alpha-2u globulin. This lesion is present in the male rat only but not in the female, because the female rat does not synthesize alpha-2u globulin.
A higher relative weight of kidneys with increased blood urea nitrogen and creatinine might be related to kidney lesions. A higher ASAT activity at high dose of males and increased relative liver weights, more pronounced in males than in females, might suggest an influence on the hepatic system due to treatment with the test item. However, no treatment-related pathomorphologic alterations were found at histologic examination of the livers. Clinicopathologic changes such as lowered erythrocytes counts and hematocrit values, elevated MCH and MCHC and lowered chloride concentration in females were of uncertain relationship to drug-treatment and were noted in the rats treated with 300 mg/kg bw/day.
The test item produced no clinical effects, no clinicopathological effects and no histopathologic lesions, when administered at 30 mg/kg bw/day to rats. No treatment related effects were found at dose 30 mg/kg bw/day. The administration of 95 mg/kg bw/day resulted in slight clinical effects and minimal renal lesions in the male rats. At 300 mg/kg bw/day moderate clinical and clinicopathological effects and moderate renal lesions in male rats were found.

Ref: C.L. Alden (1986) 'Unique Male Rat Xenobiotic induced Protein Nephropathy" Proceedings of the thirtyseventh Annual Meeting of the American College of Veterinary Pathologists, pp. 145 – 148.

Executive summary:

Determination of sub-acute oral toxicity was carried out with 5-ethyl-2-methylpyridine (MEP, CAS no.: 104-90-5, EC no.: 203-250-0). The read-across between the UVCB substance and the model constituent is justified. A sub-acute toxicity study was carried out according to EU Method B.7 and OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents). The test item was administered per gavage to groups of 6 rats (Sprague-Dawley, Cd: CDR (SD) BR), male and female at dose levels of 30, 95 and 300 mg/kg bw/day.

Nephropathy in the male rats at doses 95 and 300 mg/kg bw/day was the principal treatment effect following administration of the test item. The lesion might be similar to the protein nephropathy induced by xenobiotics in the male rat. Alden (1986) reported that several chemicals specifically increase alpha-2u globulin accumulation in the proximal convoluted tubular epithelium of the male rat as a primary acute toxicological effect, although it was demonstrated that the spontaneous hyaline droplet in the otherwise normal male rat-kidney consists exclusively of alpha-2u globulin. This lesion is present in the male rat only, but not in the female, because the female rat does not synthesize alpha-2u globulin.

A higher relative weight of kidneys with increased blood urea nitrogen and creatinine might be related to kidney lesions. A higher ASAT activity at high dose of males and increased relative liver weights, more pronounced in males than in females, might suggest an influence on the hepatic system due to treatment with the test item. However, no treatment-related pathomorphologic alterations were found at histologic examination of the livers. Clinicopathologic changes such as lowered erythrocytes counts and hematocrit values, elevated MCH and MCHC and lowered chloride concentration in females were of uncertain relationship to drug-treatment and were noted in the rats treated with 300 mg/kg bw/day.

The test item produced no clinical effects, no clinicopathological effects and no histopathologic lesions, when administered at 30 mg/kg bw/day to rats.

The no observed adverse effect level (NOAEL) was determined to be 30 mg/kg bw/day. The lowest observed adverse effect level (LOAEL) was determined at 95 mg/kg bw/day with slight clinical effects and minimal renal lesions in the male rats. At 300 mg/kg bw/day moderate clinical and clinicopathological effects and moderate renal lesions in male rats were found.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

30 mg/kg bw/day

Study duration:

subacute

Species:

rat

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Read-across from supporting substance Substance: 2-picoline CAS no.: 109-06-8 EC no.: 203-643-7 Substance category: Pyridine and pyridine derivative substances Read-across justification The American Chemistry Council and the US EPA developed a structure-based category for pyridine and pyridine derivative substances, based on the following similarities: - Closely-related structural and functional features; - Similar or predictable measured and modeled physical properties; - Similar or predictable measured and modeled biodegradability; - Similar or predictable measured and modeled environmental fate and toxicity; - Similar or predictable measured mammalian toxicity; and - Similar use and disposition patterns. All members of the Pyridine and Pyridine derivatives category are structurally-related derivatives of pyridine in that they are based on the pyridine unsaturated ring structure. Piperidine (CAS RN 110-89-4) is simply the saturated ring structure derivative of pyridine. The main category consists of three sub-categories I, II and III. Sub-category I contains the liquid pyridine and alkylpyridines with high water solubility and high vapor pressure: Pyridine (CAS no. 110-86-1), 2-picoline (CAS no. 109-06-8), 3-picoline (CAS no. 108-99-6), 4-picoline (CAS no. 108-89-4) and Pyridine, alkyl derivatives (CAS no. 68391-11-7). The human health assessment concluded that the acute toxicity of sub-category I is low via the oral (rats), high via the dermal (rabbits) and moderate via the inhalation (rats) routes of exposure. The alkyl pyridines are corrosive to rabbit skin and severely irritating to rabbit eye. Pyridine is not a skin sensitizer in guinea pigs. Oral repeated-dose studies with Pyridine in rats showed systemic toxicity ranging from changes in body weights to histopathological changes in the liver at 33 mg/kg bw/day with a NOAEL of 14 mg/kg bw/day. The studies on repeated inhalation toxicity included were a 4-day study with Pyridine (Nikula and Lewis, 1994, published), a 13-day study with 3-picoline (Chen, et al., 1984, EPA Doc. no. 878214922) and a six month inhalation study with 2-picoline (Watanabe et al., 1979, EPA Doc. no. 40-8341086), as part of the summary on repeated dose toxicity. Notably, the sub-chronic study on 2-picoline was considered most reliable, with a Klimisch rating of 1B vs. 2D and 2A for the Pyridine and the 2-picoline studies. None of the repeated dose inhalation studies allowed establishing a threshold for systemic toxicity. The study on Pyridine involved only the histopathology exam of nasal tissue after inhalation exposure, which was not according to guidelines. The studies on 3-picoline and 2-picoline showed no effects at the highest concentrations tested. Sub-category I of the Pyridine and Pyridine derivative substances group show similar physical-chemical, toxicological and ecotoxicological properties. A data matrix covering all available endpoints was previously published (US EPA Doc. No. 201-14925B1, 2009). An overall summary and detailed robust summaries are included in IUCLID section 13. The available data on the substances of the category reveals similar properties. In general, the classification and labeling of the model constituents is comparable to that of the target substance. Neither substance of the category is considered a PBT or vPvB substance. In summary, based on the data provided the read-across between 2-picoline and Pyridine, alkyl derivs., both part of the Pyridine and Pyridine derivative substances category (Sub-category I), is justified.

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.29 (Sub-Chronic Inhalation Toxicity:90-Day Study)

Deviations:

yes

Remarks:

Exposure period: 6 month

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

Exposure period: 6 month

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8 weeks
- Weight at study initiation: 559 to 573 (males), 302 to 314 (females)
- Fasting before study: Yes
- Diet: Ad libitum except during exposure
- Water: Ad libitum except during exposure
- Acclimation period: 19 days prior to initiation of the study

IN-LIFE DATES:
- From: 9-14-77
- To 3-14-78 (last exposure)

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Rochester type chambers
- Source and rate of air: The vapor was swept into the inlet of the exposure chamber with compressed air where it was further diluted by tempered air to the desired concentration
- Temperature, humidity, pressure in air chamber: The a-picoline vapor was generated by metering the liquid compound at a controlled rate into a temperature regulated vaporization flask (130°C).
- Air flow rate: The chambers were operated under dynamic airflow conditions (40-50 ~/min) with temperature and humidity controlled air.

TEST ATMOSPHERE
- Brief description of analytical method used: Gas liquid chromatography using direct gas sampling loops
- Samples taken from breathing zone: Yes

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The gas chromatographic conditions were as follows:
Instrument: Varian Model 2400 gas chromatograph
Detection: Hydrogen flame ionization
Column: 10' x 1/8" stainless steel column packed with 10% SP-1000 on 100/120 mesh Chromo sorb WAW
Temperatures:
- Column 160 °C
- Detector 235 °C
Gas Flow Rates:
- He (carrier): 120 ml/min
- H2: 30 ml/min
- Air: 300 ml/min
Standards for the analysis were prepared by injecting known volumes of the test material into Saran bags containing a known volume of air. The target concentrations were 5, 35 and 100 ppm.
For results see table 1 below.

Duration of treatment / exposure:

Approximately 6 months (males 124 exposures in 182 days, females 125 exposures in 183 days)

Frequency of treatment:

6 hours/day, 5 days/week

Remarks:

Doses / Concentrations:
0, 5, 35, or 100 ppm
Basis:
nominal conc.

Remarks:

Doses / Concentrations:
0, 5.1 ± 0.5, 35.4 ± 1.6 and 99.8 ± 6.4 ppm
Basis:
analytical conc.

No. of animals per sex per dose:

20 rats (10/sex) per dose

Control animals:

yes, concurrent no treatment

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule for examinations: Prior to exposure and at monthly intervals thereafter
- Parameters: observations of respiration, piloerection, exophthalmos/palpebral closure and tremor

BODY WEIGHT: Yes
- Time schedule for examinations: Twice weekly for the first 4 weeks of exposure and weekly thereafter.

ORGAN WEIGHT: Yes
- Organ weights for liver, kidneys, brain, heart, and testes (male) were obtained from all animals at necropsy, and organ/body weight ratios were calculated.

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At the termination of the exposure (6 months)
- Anaesthetic used for blood collection: Yes (identity) / No / No data
- Animals fasted: Yes
- How many animals: 10
- Parameters: Hematological parameters included red blood cell counts, white blood cell counts (Coulter Counter, MOdel ZBI, Coulter Electronics, Hialeah, FL) and white blood cell differential counts, hemoglobin concentration (Hemoglobinometer, Coulter Electronics, Hialeah, FL) and packed cell volume.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At the termination of the exposure (6 months)
- Animals fasted: Yes / No / No data
- How many animals: 10
- Parameters: Clinical chemistry studies included the determination of blood urea nitrogen (BUN), serum glutamic pyruvic transaminase (SGPT), serum alkaline phosphatase, and serum glucose levels (Centrifichem Methods, Union Carbide Co., Rye, NY).

URINALYSIS: Yes
- Time schedule for collection of urine: At the termination of the exposure (6 months)
- Animals fasted: Yes
- How many animals: 10
- Parameters: Urinalysis included determination of pH, sugar, ketones, bilirubin, occult blood, urobilinogen, protein (Ames Multilabstix, Ames Co., Elkhart, IN) and specific gravity (TS Meter, AO Optical, Buffalo, NY).

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: Prior to exposure and at monthly intervals thereafter
- Dose groups that were examined: Five rats per sex per group
- Battery of functions tested: 3 simple tasks for evaluating sensory stimuli and motor function responses were conducted. For the visual placing test, the animal is lifted by the tail to a height of about 20 cm above a bench top and lowered to the bench top to elicit the visual placing response which is usually characterized by an extension of both fore and hind limbs before contact. The wire maneuver test is conducted by allowing the animal to grasp a horizontal wire with its forelimbs (hanging in midair) and subsequently observing the ability of the animal to lift its hind limbs to the wire. The hind limb. grasp test consists of placing the animal head down on a vertical, cylindrical post and observing the ability of the hind limbs to grasp the post, thus preventing the animal from immediately falling.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
- Gross necropsies were conducted on all animals.

HISTOPATHOLOGY: Yes
- Representative specimens of organs and tissues were taken from all animals and fixed in 10% neutral buffered formalin. Histopathologic examination of all gross lesions, liver, kidney, lung, brain and spinal cord were conducted on all rats of the control and 100 ppm exposure groups. The above tissues were processed by conventional methods, embedded in paraffin blocks, sectioned (6-8 um), stained with hematoxylin and eosin and evaluated by light microscopy. Particular attention was given to examination of nervous tissue. The brain was fixed in toto and the spinal cord was removed intact within the vertebral column. After fixation, the brain was serially crosssectioned at 5 different levels, starting in the rostral portion of the cerebrum and proceeding caudally to include the components of the brain stem and cerebellum. The spinal cord was removed from the vertebral canal before preparing both longitudinal and cross-sectional specimens from the cervical, thoracic and lumbosacral regions. The sections of brain and spinal cord were stained with Margolis' and Pickettts Luxol Fast Blue-Periodic Acid-Schiff Hematoxylin Method (Putt, 1972). All sections were examined by light microscopy.

Statistics:

Hematology, clinical chemistry, organ and body weight data were analyzed using an analysis of variance and Dunnett's test (Steel and Torrie, 1960). The level of significance in all cases was p <0.05. The sensory and motor function test results were analyzed using Fisher's exact probability test at a significance level of p <0.05, (Siegel, 1956).

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

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

Details on results:

CLINICAL SIGNS AND MORTALITY
The animals were observed daily throughout the study and there were no signs of toxicity observed at any treatment level at any time. There were no mortalities throughout the study. The monthly observations made during the sensory/motor function testing which includes observations on respiration, piloerection, exophthalmos/palpebral closure, tremor and the visual placing test were normal for all animals tested throughout the study. Based on results for the wire maneuver and hind limb clamping tests there were no statistically significant differences noted which indicated any deficit in motor function performance due to treatment. The sporadic statistically significant findings all suggested that the treatment groups performed better than controls. These findings, however, did not demonstrate any strong dose or time response relationship and were thus attributed to normal variation. It was observed that after the second or third months on study it was very difficult to judge the male rats on the wire maneuver test because they had gained so much weight that none of the rats, including the controls, were able to perform as they had done earlier in the study.
Therefore, the wire maneuver results for the latter half of the study are not very meaningful. While not statistically significant the wire maneuver results for male rats in the 5th and 6th month seem to suggest there may have been a deficit in response at the highest exposure level. However, for the reasons mentioned above and the lack of any histopathologic evidence suggesting damage to the nervous system these results are likely due to animal variation and have little or no toxicologic significance.

BODY WEIGHT AND WEIGHT GAIN
Body weight data showed no differences between control and rats exposed to the test item. The relative weights of heart and liver in males exposed to 5 and 100 ppm respectively were the only values which were statistically increased when compared to control values. The increase in the relative heart weight was barely significant statistically and did not demonstrate a dose-response relationship. Since there were no other indications of toxicity, this observation was considered to be of no toxicologic significance. The increase in the relative liver weight in males exposed to 100 ppm test item was associated 'with an increased absolute liver weight. Similarly, in females exposed to 100 ppm test item there was a suggestion that both the absolute and relative liver weight was increased with no dose response relationship observed. Histopathologic examination did not reveal any treatment related effects in either males or females exposed to 100 ppm attest item. Thus the suggestion of an increased liver weight mayor may not be of toxicologic significance.

HAEMATOLOGY, CLINICAL CHEMISTRY, URINALYSIS
The only statistically significant difference observed was a decrease in the red blood cell (RBC) count in male and female rats exposed to higher concentrations of test item. To confirm whether this was real, the RBC count for males was repeated. Since the effect was not reproducible, it was concluded that the initial observation was an artifact. Female rats exposed to 100 ppm test item also showed a statistically significant decreased RBC count. However, the PCV was not different from controls. Furthermore, the RBG value, while statistically significant, was within the normal range (within ± 1 S.D.) of historical control rats of similar age and sex. Therefore this observation was not judged to be toxicologically significant. No differences were observed in group means for control and exposed animals.

PATHOLOGY
All observations were considered to be spontaneous in nature and were typical of those commonly observed in rats of this strain and age. Thus, no grossly visible lesions could be attributed to exposure to the test item. Histopathologic examination was conducted on all rats in the control and 100 ppm exposure groups. There were no histopathologic observations considered to be related to test item exposure. All observations were considered to be spontaneous in nature and were typical of those commonly observed in rats of this strain and age.

Dose descriptor:

NOEC

Effect level:

> 100 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Critical effects observed:

not specified

Conclusions:

Male and female Sprague-Dawley rats were exposed to 0, 5, 35 or 100 ppm test item vapor 5 days per week for 6 months. There were no effects judged to be related to treatment by the parameters measured. The parameters included urinalysis, clinical chemistry, hematology, body weights, organ weights, sensory/motor function performance and gross pathology. Furthermore, histopathologic examination with special emphasis on the central nervous (CNS) conducted on the control and 100 ppm exposure groups did not indicate any effects attributable to exposure to the test item.

Executive summary:

Determination of acute inhalation toxicity was carried out with 2-picoline (CAS no.: 109-06-8, EC no.: 203-643-7). The read-across between 2-picoline and Pyridine, alkyl derivs., both part of the Pyridine and pyridine derivative substances category (sub-category I), is justified.

A sub-chronic repeated dose toxicity study (6 month) was carried out equivalent or similar to EU Method B.29 and OECD Guideline 413 (Subchronic Inhalation Toxicity). Male and female Sprague-Dawley rats were exposed to 0, 5, 35 or 100 ppm test item vapor 5 days per week for 6 months. Nominal concentrations correspond to 0, 5.1 ± 0.5, 35.4 ± 1.6 and 99.8 ± 6.4 ppm measured. Parameters assessed included urinalysis, clinical chemistry, hematology, body weights, organ weights, sensory/motor function performance and gross pathology. Furthermore, histopathologic examination with special emphasis on the central nervous (CNS) was conducted on the control and 100 ppm exposure groups.

No signs of toxicity were observed at any treatment level at any time. There were no statistically significant differences noted that indicated any deficit in motor function performance due to treatment. There were no statistically significant differences in the body weights of those rats in any treatment group when compared to the control. There were no statistically significant differences between organs of treatment and control groups that were considered to be treatment-related. Histopathologic examination did not reveal any treatment-related effects in ether males or females exposed to 100 ppm of the test substance. There were no statistically significant differences between hematological parameters of treatment and control groups that were considered to be treatment-related. No grossly visible lesions could be attributed to test substance exposure.

No threshold for systemic toxicity was established. The NOAEC (NOEC) was determined to be 100 ppm equivalent to 0.38 mg/L.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

380 mg/m³

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Repeated dose toxicity – oral

Determination of sub-acute oral toxicity was carried out with 5-ethyl-2-methylpyridine (MEP, CAS no.: 104-90-5, EC no.: 203-250-0). The read-across between the UVCB substance and the model constituent is justified. A sub-acute toxicity study was carried out according to EU Method B.7 and OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents). The test item was administered per gavage to groups of 6 rats (Sprague-Dawley, Cd: CDR (SD) BR), male and female at dose levels of 30, 95 and 300 mg/kg bw/day.

Nephropathy in the male rats at doses 95 and 300 mg/kg bw/day was the principal treatment effect following administration of the test item. The lesion might be similar to the protein nephropathy induced by xenobiotics in the male rat. Alden (1986) reported that several chemicals specifically increase alpha-2u globulin accumulation in the proximal convoluted tubular epithelium of the male rat as a primary acute toxicological effect, although it was demonstrated that the spontaneous hyaline droplet in the otherwise normal male rat-kidney consists exclusively of alpha-2u globulin. This lesion is present in the male rat only, but not in the female, because the female rat does not synthesize alpha-2u globulin.

A higher relative weight of kidneys with increased blood urea nitrogen and creatinine might be related to kidney lesions. A higher Aspartate-aminotransferase (ASAT) activity at high dose of males and increased relative liver weights, more pronounced in males than in females, might suggest an influence on the hepatic system due to treatment with the test item. However, no treatment-related pathomorphologic alterations were found at histologic examination of the livers. Clinicopathologic changes such as lowered erythrocytes counts and hematocrit values, elevated Mean cell hemoglobin (MCH) and Mean cell hemoglobin concentration (MCHC) and lowered chloride concentration in females were of uncertain relationship to drug-treatment and were noted in the rats treated with 300 mg/kg bw/day.

The test item produced no clinical effects, no clinicopathological effects and no histopathologic lesions, when administered at 30 mg/kg bw/day to rats.

The no observed adverse effect level (NOAEL) was determined to be 30 mg/kg bw/day. The lowest observed adverse effect level (LOAEL) was determined at 95 mg/kg bw/day with slight clinical effects and minimal renal lesions in the male rats. At 300 mg/kg bw/day moderate clinical and clinicopathological effects and moderate renal lesions in male rats were found.

Repeated dose toxicity – inhalation

Determination of acute inhalation toxicity was carried out with 2-picoline (CAS no.: 109-06-8, EC no.: 203-643-7). The read-across between 2-picoline and Pyridine, alkyl derivs., as part of the Pyridine and pyridine derivative substances category, is justified (see rational for reliability in IUCLID section 7.5.2 for details).

A sub-chronic repeated dose toxicity study (6 month) was carried out equivalent or similar to EU Method B.29 and OECD Guideline 413 (Subchronic Inhalation Toxicity). Male and female Sprague-Dawley rats were exposed to 0, 5, 35 or 100 ppm test item vapor 5 days per week for 6 months. Nominal concentrations correspond to 0, 5.1 ± 0.5, 35.4 ± 1.6 and 99.8 ± 6.4 ppm measured. Parameters assessed included urinalysis, clinical chemistry, hematology, body weights, organ weights, sensory/motor function performance and gross pathology. Furthermore, histopathologic examination with special emphasis on the central nervous (CNS) was conducted on the control and 100 ppm exposure groups.

No signs of toxicity were observed at any treatment level at any time. There were no statistically significant differences noted that indicated any deficit in motor function performance due to treatment. There were no statistically significant differences in the body weights of those rats in any treatment group when compared to the control. There were no statistically significant differences between organs of treatment and control groups that were considered to be treatment-related. There were no toxicologically significant differences in hematology, clinical chemistry and urinalysis. Histopathologic examination did not reveal any treatment-related effects in either males or females exposed to 100 ppm of the test substance. No grossly visible lesions could be attributed to test substance exposure.

The NOAEC (NOEC) was determined to be 100 ppm equivalent to 0.38 mg/L. No threshold for systemic toxicity was established.

Repeated dose toxicity – dermal

According to REACH Annex VIII column 1 and 2 section 8.6.1 repeated dose toxicity testing via the dermal route was waived. Instead data on repeated dose toxicity testing via the oral route is presented. A NOAEL long-term, dermal of 30 mg/kg bw/day was calculated from the NAOEL long-term, oral of 30 mg/kg bw/day, assuming 100 % resorption through the skin.

Justification for classification or non-classification

Based on the data available the substance is not classified and labeled according to Regulation 1272/2008/EEC (CLP) and Directive 67/548/EEC (DSD).