4-chloro-α,α,α-trifluorotoluene

Toxicity to reproduction

Administrative data

Endpoint:

one-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 1980-June 1981

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 415 [One-Generation Reproduction Toxicity Study (before 9 October 2017)]

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

4-chloro-α,α,α-trifluorotoluene

EC Number:

202-681-1

EC Name:

4-chloro-α,α,α-trifluorotoluene

Cas Number:

98-56-6

Molecular formula:

C7H4ClF3

IUPAC Name:

1-chloro-4-(trifluoromethyl)benzene

Details on test material:

- Name of test material (as cited in study report): parachlorobenzotrifluoride (PCBTF)
- Substance type: intermediate
- Physical state: clear liquid
- Analytical purity: 97%
- Stability: chemically stable and moderately volatile
- Storage condition of test material: clear glass jars, ambient temperature

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Taconic Farms, Inc., New York
- Age at study initiation: F0 ( parental): 8 weeks old
- Housing: housed indvidually in standard stainless steel suspended rat cages in an environmentally controlled animal room.
- Diet: ad libitum, Purina certified rodent chow 5002
- Water: ad libitum, tap water, analyzed quarterly
- Acclimation period: F0 animals were acclimated for 24 days prior to dosing.

ENVIRONMENTAL CONDITIONS
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 dark, 12 light

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

During the acclimation period (24 days) rats were periodically dosed with corn oil to accomodate them to the gavaging procedure. Rats were examined for masses and observed for abnormal behavioral reactions. Based on these observations, 80 healthy males and 80 healthy females were assigned randomly
to four treatment groups by sex. An additional 5 males and 5 females were selected randomly to be utilized in establishing baseline clinical pathology values.
Rats were divided randomly into four treatment groups: Group I (control), Group II (5 mg/kg/day), Group III (15 mg/kg/day), Group IV (45 mg/kg/day). Rats were dosed in 2 ml/kg body weight volumes via gavage with test solutions of varying concentrationsfor each dosage.

F1 rats vere administered test material orally via gavage for 90 days and until sacrifice.

Details on mating procedure:

F0 rats were dosed for four weeks prior to mating and through one reproduction period until F1 litters bad been weaned. After F0 rats had been administered the test material in corn oil for four weeks, F0 females were housed on a one-to-one basis with males from the same test group for the purpose of mating. The presence of a copulatory plug was considered positive evidence of mating. When copulatory plugs were found, males were removed and returned to individual cages. If after one week, no evidence of positive mating was observed, the male was removed and a different male of the same dose group was placed with the female. Day one of gestation was defined as the first day that a copulatory plug was observed. Approximately five days prior to parturition, each female was placed in a plastic shoe box cage equipped with a stainless steel top. Bedding was changed twice weekly or more often if needed through weaning. Females were disturbed for daily dosing, bedding changes and data collection only. Except for emergencies females were not disturbed for any reason during labor, delivery, or until pups had been cleaned and nursed for the first time.

Duration of treatment / exposure:

Test was aadministered to the parental (F0) rats for 76 to 83 days. Weanling F1 rats were dosed for at least 90 days.

Frequency of treatment:

Daily

Details on study schedule:

At 21 days of age, pups were weaned and weighed. F1 pups were selected raadomly from all litters within a group for assigmnent to corresponding treatment groups. Two extra rats of each sex were salected from each group to allow for replacement of any experimental rats that died during the initial dosing period. Day 21 of age for the youngest F1 pups coincided with day 1 of dosing for the F1 rats. All rats weaned prior to day 1 were dosed daily from weaning until the youngest F1 pups had reached 21 days of age.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

5 mg/kg diet

Remarks:

Basis: nominal in diet (Group II)

Doses / concentrations 2

Dose / conc.:

15 mg/kg diet

Remarks:

Basis: nominal in diet (Group III)

Doses / concentrations 3

Dose / conc.:

45 mg/kg diet

Remarks:

Basis: nominal in diet (Group IV)

No. of animals per sex per dose:

20 males and 20 females for each dose group.

Control animals:

yes, concurrent vehicle

Details on study design:

Dose selection rationale: based on a prelimary pilot stydy of 14 days.

Examinations

Parental animals: Observations and examinations:

All rats were observed twice daily five days a week and once daily on weekends. Animals were checked for general appearance, behavior, elimination, and signs of toxic or pharmacologic effects. Daily observations were recorded and unusual appearance or behavior was reported. During the mating period, femles were observed for presence of the copulatory plug as positive evidence of mating.

F0 rats were weighed weekly.
Weekly individual feed consumption was recorded weeks 1-4 of study.

Blood was obtained for hematology and clinical chemistry determinations from the following randomly selected animals:
1) 5 males an 5 females prior to the initiation of dosing
2) 5 F0 males and 5 F0 females from each group after 2 weeks of study
3) 5 F1 males and 5 F1 females from each group prior to sacrifice at termination of the study.

All rats were fasted overnight and anesthetized with ether prior to collection of blood samples. Blood was collected from the
suborbital sinus in F0 rats.

Litter observations:

F1 rats were weighed on days 1 (day of birth), 4 and 21, and weekly thereafter. Mean body weights and mean weight gains since date on test were computed and compared by sex for statistically signi£icant differences among groups. Individual body weights were used for weekly dose adjustments . Terminal body weights were recorded for all rats.

Gross pathology and histopathological examinations were performed on all F1 animals, and selected organ weights were recorded. Organ/body weight ratios were calculated.

Litter data were collected on the following: total number of pups born alive and dead; number of male and female pups on days 1, 4, 14 and 21; individual pup weights, average pup weight/litter and dam weight on days 1, 4 and 21; and the number (percent) of pups surviving on days 4, 14 and 21. Litters were culled to 10 on day 14. Therefore, survivability data was calculated for day 14 based on counts before culling and data for day 21 was based on litter counts after culling.

Weekly individual feed consumption was recorded weeks 13-25 of study. Total weekly feed consumption was recorded for each rat, and group means
were compared by sex for statistically significant differences.

Postmortem examinations (parental animals):

After a sufficient number of F1 pups had whelped, F0 males were killed and subjected to a complete gross necropsy. F0 females were killed and necropsied after all litters had-been weaned.

Postmortem examinations (offspring):

All rats were fasted overnight and anesthetized with ether prior to collection of blood samples. Blood was collected via cardiac puncture in F1 rats.

Statistics:

Statistical analyses were perfomed on all tested measurable parameters.
Whenever a probability value of less than 0.05 was found, a Tukey's HSD procedure was performed to detect statistically significant differences among groups. All data which were analyzed statistically (litter data, body weights, feed consumption, hematology, clinical chemistry, and absolute organ weights) were recorded on computer coding forms and keypunched into the computer. Statistics were generated by the Statistical Package for the Social Sciences (SPSS) program.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Gains for study groups significantly gretaer ( p<0.05) than for controls in all male treatment groups for week 14, and for Group II males in week 15. Group IV females had decreased weight gains during weeks 15 and 16.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Gains for study groups significantly gretaer ( p<0.05) than for controls in all male treatment groups for week 14, and for Group II males in week 15. Group IV females had decreased weight gains during weeks 15 and 16.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

no effects observed

Description (incidence and severity):

Test substance intake: No dosage-related trends were evident.

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

no effects observed

Details on results (P0)

Clinical pathology: The percent monocytes for Group II (5 mg/kg) females was significantly (p < 0.05) decreased at day 14 compared with controls. Erythrocyte counts were significantly (p < 0.05) decreased in Group II (5 mg/kg) females compared with controls. Mean corpuscular hemoglobin (MCH) values were significantly reduced in all male treatment groups but these values were within normal historical limits. No corresponding effect in MCH values was present in female treatment groups. Group IV (45 mg/kg) females had decreased mean corpuscular hemoglobin concentration (MCHC) and increased mean corpuscular volume (MCV). These values were within normal historical limits.

Individual urine analysis determinatiotns for baseline animals, F0 animala on day 14, and F1 animals at termination recorded values within normal limits.

The changes observed in the respiratory system (lung) were those commonly accompanying an oral gavage study in which occasional inhalation of the test material or control material may be anticipated. The prostate gland inflammatory lesion, recognized in both dose groups examined were attributed to spontaneous disease phenomena.

Effect levels (P0)

Dose descriptor:

NOAEL

Effect level:

>= 45 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No signs of significant adverse effects observed

Target system / organ toxicity (P0)

Critical effects observed:

no

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

Effect levels (F1)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

45 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Overall reproductive toxicity

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Under the conditions of the test and at the dosages given, the test item PCBTF was found to be safe at all levels. A toxic no-effect level in rats was greater than or equal to 45 mg/kg.

Executive summary:

170 Sprague-Dawley rats were used to test the subchronic toxicity of PCBTF in F1 rats following in utero exposure. Rats were divided randomly into 4 treatment groups: Group I (control), Group II (5 mg/kg/day), Group III (15 mg/kg/day), Group IV ( 45 mg/kg/day). Rats were dosed in 2 mL/kg body weight volumes via gavage with test solutions of varying concentrations for each dosage. Test material was administered to the parental (F0) rats for 76 to 83 days. F0 rats were killed and subjected to a gross necropsy. Weanling F1 rats were dosed for at least 90 days, then killed and necropsied.

Throughout the study, weekly feed consumption and body weights were recorded; new doses were calculated weekly on the basis of current body weights. Clinical pathology parameters were obtained predose on baseline animals, after 14 days treatment of F0 rats, and terminally on F1 animals, and selected organ weights were recorded. Organ/body weight ratios were calculated. Statistical aualysis were perfomed on all tested measurable parameters. Clinical observations, clinical pathology parameters, and histopathology examinations showed no treatment related abnormalities.

A trend was observed in main liver weights and mean liver/body weight ratios among treatment groups. The effects seen were a physiologic response of this organ to PCBTF. The increased metabolic response did not reflect necessarily a toxic response to the test material. No other treatment related effects were observed. Under the conditions of the test, the test item PCBTF was found to be safe at all levels. A toxic no-effect level in rats was greater than or equal to 45 mg/kg.