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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1982-03-02 to 1982-06-05
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study, to GLP
Cross-reference
Reason / purpose:
reference to same study

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1984
Report Date:
1984
Reference Type:
publication
Title:
Summaries of toxicological data. Toxicology of chlorinated paraffins
Author:
Serrone DM, Birtley RDN, Weigand W and Millischer R
Year:
1987
Bibliographic source:
Fd Chem Toxicol. 25: 553-562
Reference Type:
secondary source
Title:
Unnamed
Year:
2000

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Deviations:
yes
Remarks:
neurobehavioural examination not included
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): C10-12 chlorinated paraffins (58% chlorinated)
- Substance type: technical product
- Physical state: clear, slightly viscous liquid
- Analytical purity: "100% chlorinated paraffins"
- Impurities (identity and concentrations): free hydrochloric acid (HCl) - 7 ppm ; no stabiliser
- Composition of test material, percentage of components: C10-12 chlorinated paraffin (58% chlorinated)
- Purity test date: no data
- Lot/batch No.: R-201-198
- Expiration date of the lot/batch: "Dependent on routine analysis"

Test animals

Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding laboratories, Kingston, New York
- Age at study initiation: 6 weeks
- Weight at study initiation: males - 76 to 125 g; females - 70 to 101 g
- Fasting period before study: none
- Housing: individually in hanging wire-mesh cages
- Diet (e.g. ad libitum): Certified rodent diet #5002
- Water (e.g. ad libitum): ad lib
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): average 22.8
- Humidity (%): average 60
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 1982-03-02 To: 1982-06-05

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): weekly
- Mixing appropriate amounts with (Type of food): Certified rodent diet #5002
- Storage temperature of food: refrigeration

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Diet samples extracted with hexane and extract dried under vacuum. Residue combusted in oxygen, dissolved in water and titrated potentiometricallyagainst standardised silver nitrate solution.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
Continuous in the diet
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
10, 100 and 625 mg/kg/day
Basis:
nominal in diet
Remarks:
Doses / Concentrations:
10, 101 and 654 mg/kg/day (males) and 10.3, 102 and 613 mg/kg/dat (females)
Basis:
actual ingested
No. of animals per sex per dose:
15
Control animals:
yes, plain diet
Details on study design:
Animals randomised to homogeneous groups (Bartlett's Chi-squared test)
Positive control:
no

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily - morbidity, mortality, skin atonia

BODY WEIGHT: Yes
- Time schedule for examinations: 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: Yes

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: daily

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: pre-study and week 12
- Dose groups that were examined: all

HAEMATOLOGY: Yes
- Time schedule for collection of blood: 4 , 8 and 13 weeks
- Anaesthetic used for blood collection: No
- Animals fasted: Yes (not a week 4)
- How many animals: 10/sex/dose group
- Parameters: Hb, HCT, erythrocyte and platelets count, total and differential leucocytes, MCV, MCH, MCHC, clotting time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: 5, 8 and 13 weeks
- Animals fasted: Yes
- How many animals: 10/sex/dose
- Parameters: Na, K, Ca, Cl, P, AlkP, AST, ALT, LDH, BUN, protein, cholesterol, glucose

URINALYSIS: Yes / No / No data
- Time schedule for collection of urine: 4 or 5, 8 and 13 weeks
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters: colour, appearance, sediment, SG, volume, osmolality, pH, protein, glucose, occulu blood, nitrite, ketones, bilirubin, urobilinogen

NEUROBEHAVIOURAL EXAMINATION: No

OTHER: bone marrow smear, liver enzymes
Sacrifice and pathology:
Gross pathology and histopathological examinations made of a comprehensive range of organs and tissues
Other examinations:
Liver total protein, cytochrome P450 and aminopyrine N-demethylase activity determined at autopsy
Statistics:
Treatment groups compared with control group by one-way analysis of variance, Barlett's test for homogeneity of variance and appropriate t test. Significance judged using Dunnett's multiple comparison tables. Selected parameters were compared by non-parametric tests.

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
slight reduction in food consumption in top-dose females
Food efficiency:
no effects observed
Water consumption and compound intake (if drinking water study):
effects observed, treatment-related
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
effects observed, treatment-related
Behaviour (functional findings):
not specified
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 deaths occurred and no clinical signs were observed except for slight skin atonia in 5 top-dose males, 3 top-dose females and 1 mid-dose female

BODY WEIGHT AND WEIGHT GAIN: body weight gain reduced by 9% in top-dose males

WATER CONSUMPTION: decreased by 11 and 20% in top-dose males and females respectively

HAEMATOLOGY: slight (significant) decrease in erythrocyte count, Hb and HCT in top-dose males and females and Hb in mid-dose females

CLINICAL CHEMISTRY: treatment-related increases seen in total protein (up to 13%), cholesterol (up to 54%), glucose (up to 20%) and BUN (up to 44%) in top- and mid-dose groups

URINALYSIS: Urine volume decreased and specific gravity increased in top-dose males and females.

ORGAN WEIGHTS: absolute and relative liver weight (combined) increased by about 20 and 140% in mid- and top-dose animals, respectively; absolute and relative kidney weights (combined) increased by about 10 and 30% in mid- and top-dose animals, respectively; absolute and relative thyroid weight (combined) increased by about 32% in top-dose animals

HISTOPATHOLOGY: NON-NEOPLASTIC:
Males - hepatocellular hypertrophy, nephritis and thyroid hypertrophy and hyperplasia seen in mid- and top dose animals;
Females - hepatocellular hypertrophy seen in mid- and top-dose animals; renal tubule pigmentation and thyroid hyperplasia and hypertrophy in top-dose animals only

OTHERS:
Males - "slight" dose-related increase in liver protein content seen, with corresponding increases in cytochrome P450 and aminopyrine N-demethylase activity, particulary in top-dose animals.
Females - no effects on liver parameters

Effect levels

Dose descriptor:
NOEL
Effect level:
ca. 10 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Effects on body weight gain, organ weights, urine, liver biochemistry and pathology at higher dose levels

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
In a guideline study to GLP, no adverse effects were seen in male and female Fischer 344 rats fed a C10-12 chlorinated paraffin (58% chlorinated) for 13 weeks in the diet at 10 mg/kg bw/day. At higher dose levels, effects were seen on body weight gain, organ weights, urinary parameters, blood and liver biochemistry and liver, kidney and thyroid histopathology. The overall no-observed-effect level (NOEL) in the study was 10 mg/kg bw/day.
Executive summary:

In a 13-week GLP study, similar to OECD Guideline 408, groups of male and female Fischer 344 rats (15/sex/dose) were given a C10-12 chlorinated paraffin (58% chlorinated) in the diet at nominal dose levels of 10, 100 and 625 mg/kg bw/day (actual intakes were 10, 101 and 654 mg/kg bw/day for males and 10.3, 102 and 613 mg/kg bw/day for females). During the study, animals were observed for clinical signs of toxicity. Food and water consumption was determined and haematological and urinary analyses performed. At the end of the feeding period, animals were weighed and a range of organs examined for gross and histopathological changes. Livers were also recovered for biochemical investigations.

No deaths occurred and no clinical signs of toxicity (other than slight skin atonia in top-dose males) were observed during the study. A slight reduction in body weight gain (9% compared to controls) was noted in top-dose males after 13 weeks and a reduction in water consumption was seen in top-dose males and females (11 and 20%, respectively). This was associated with a decrease in urine volume and an increase in specific gravity. Increases in blood total protein (13%), cholesterol (54%), glucose (20%) and urea nitrogen (44%) were also seen in top-dose animals and in glucose (20%), cholesterol and urea nitrogen in mid-dose animals. Statistically significant increases in liver (about 20 and 140%) and kidney (10 and 30%) weights were seen in mid- and top-dose animals, respectively, and in thyroid weight (about 32%) in top-dose animals only. Histopathological changes seen included hepatocellular hypertrophy in both mid- and top-dose males and females, mild chronic nephritis in mid- and top-dose males and renal tubule pigmentation in top-dose females, and thyroid hypertrophy and hyperplasia in mid-dose males and top-dose males and females.

The no-observed-effect level (NOEL) in the rat for the C10-12 chlorinated paraffin (58% chlorinated) investigated in this study is 10 mg/kg bw/day.