Registration Dossier
Registration Dossier
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EC number: 206-996-5 | CAS number: 420-46-2
Endpoint summary
Administrative data
Key value for chemical safety assessment
Effects on fertility
Description of key information
In a 2-generation, inhalation, reproduction study conducted on the read-across source substance HFC 245fa in Sprague-Dawley rats. The NOAEC was identified to be 2000 ppm based on mortality in several dams in the medium and high level exposure group of the P0 and F1 generation. There was an increase in abnormal findings in the brain and heart that appear to be related to exposure to HFC-245fa seen predominately in the high level exposure group. Brain lesions were not seen in males or non-pregnant females. There was an increase in the number of still-born pups combined with pups not surviving until Day 4 pp in the high level exposure group of the F2 generation. A decrease in sperm motility was found in the high dose males of the F0 generation, but these effects were not seen in the F1 generation.
In support of the key study above three supporting studies are also inlcuded and summarised here:
In a dominant lethal assay on a structurally related substance (1,1,1,2-tetrafluoroethane), CD1 male mice were exposed to up to 50000 ppm for 5 days. The study indicated that the substance did not affect male fertility or cause mutagenic effects through sperm.
In a fertility study on a structurally related substance (1,1,1,2-tetrafluoroethane), rats were exposed to up to 50 000 ppm throughout gametogenesis, mating, pregnancy and lactation. There were no adverse effects on the fertility and reproductive performance of treated animals or on the development, maturation or reproductive performance of up to two successive generations.
In a 13-week inhalation toxicity study, rats were exposed to up to 137000 mg/m3 (40000ppm) 6-hr/day, 5 days/wk . Histopathological examination of control and high exposure level group rat reproductive organs did not reveal any evidence for effects on the reproductive organs.
Overall the available studies show no evidence of any adverse effect on reproduction.
Link to relevant study records
- Endpoint:
- two-generation reproductive toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 7th June 2004 - 4th April 2006
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
- Deviations:
- yes
- Remarks:
- Oestrous cycles were not recorded.
- Qualifier:
- according to guideline
- Guideline:
- EPA OPPTS 870.3800 (Reproduction and Fertility Effects)
- Principles of method if other than guideline:
- The study described in this report was conducted following the reproductive study guidelines as described in U.S. EPA Health Effects Test Guidelines OPPTS 870.3800 Reproduction and Fertility Effects (August 1998) and OECD Guideline 416 Two-Generation Reproduction Toxicity Study (January 2001) and in compliance with the Principles of Good Laboratory Practice (German Chemicals Law § 19a, Appendix 1, pp. 2119 2129, BGB1. I, June 28, 2002) and German Animal Protection Law (Tierschutzgesetz) of May 25, 1998.
- GLP compliance:
- yes
- Limit test:
- no
- Justification for study design:
- The dose levels were based on the results of a 13-week study conducted with doses of 0, 500, 2000, 10000 and 50000 ppm of the substance. The nose-only inhalation was chosen since a whole-body inhalation exposure was incompatbile with German legislation due to the high amount of substance released.
- Specific details on test material used for the study:
- SOURCE OF TEST MATERIAL
- Lot/batch number of test material: 0050404064004
- Species:
- rat
- Strain:
- Sprague-Dawley
- Details on species / strain selection:
- Hsd:Sprague Dawley SDr
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- Sprague Dawley rats approximately 4 weeks old were obtained from Harlan Winkelmann. They were acclimated to the exposure tubes for 3 weeks prior to treatment. Each animal was given a unique number. They were housed individually in polycarbonate cages type III. They were fed 1314 N specially prepared pelleted chow from Altromin International, Lage, Germany, ad libitum. Fresh tap water was provided ad libitum in 300 ml polycarbonate bottles and changed weekly. The temperature in the animal room was maintained at 20-24°C and the rel. humidity 40-70%. The lighting in the animal housing room was maintained on a 12 hr light/dark cycle.
- Route of administration:
- inhalation
- Type of inhalation exposure (if applicable):
- nose/head only
- Vehicle:
- unchanged (no vehicle)
- Details on exposure:
- Method of administration or exposure: Nose only administration. The exposures were conducted in four identical oro-nasal exposure chambers of cylindrical shape with four levels, each housing 16 rats. Rats were placed around the chambers in tapered acrylic glass tubes with adjustable back stops. The exposure cylinder was operated at a slightly positive pressure. The exposure atmosphere was generated by injecting a defined mass flow of HFC-245fa into a constant air flow.. The air flow rates were controlled by mass flow meters.
- Details on mating procedure:
- Animals were mated beginning after 10 weeks of exposure for four consecutive weeks or until successful mating as indicated by the presence of sperm or a vaginal plug. Over night mating was preformed with one male and one female from the same treatment group. The time to successful insemination (precoital time) was recorded.
- Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- The HFC-245fa concentration was measured using a flame ionization detector (FID). For the FID measurement, the test and control atmospheres were sampled every 10 min. The FID was calibrated against n-butane so drifts in the detector could easily be detected. The exposure levels of HFC-245fa were determined by comparison to the n-butane signals based on a calabration curve.
- Duration of treatment / exposure:
- Exposures were 4 hours per day
- Frequency of treatment:
- Duration of exposure per day: 4 hours
Dosing regime P0: 7 days/week (males)
Dosing regime P0: 7 days/week (females)
Dosing regime F1: 7 days/week (males)
Dosing regime F1: 7 days/week (females) - Details on study schedule:
- F0 animals were exposed for 10 weeks prior to mating and during the mating period. After successful mating, females were exposed daily from day 0 to day 20 post-conception (p.c.) as well as from day 5 post partum (p.p.) to day 20 p.p. Daily exposure of animals not successfully mated was continued until sacrifice. After completion of weaning on day 21 p.p., F1 animals were trained to the tubes for 2-3 weeks. Daily exposure of the F1 animals started thereafter and lasted 10 weeks before mating and during mating. Females were exposed daily from day 0 to day 20 p.c. as well as from day 5 to day 20 p.p. Daily treatment of males and females not successfully mated was continued until their sacrifice.
- Dose / conc.:
- 0 ppm
- Dose / conc.:
- 2 000 ppm
- Dose / conc.:
- 10 000 ppm
- Dose / conc.:
- 50 000 ppm
- No. of animals per sex per dose:
- 30 males and 30 females except for top dose F1 which had 27 males and 27 females.
- Control animals:
- yes, sham-exposed
- Details on study design:
- Exposure levels were based on a previous 13 week inhalation toxicity study that was conducted at levels of 0, 500, 2000, 10000 and 50000 ppm.The main finding was myocarditis in most animals in the 10000 and 50000 ppm groups. No effects were seen at the lower levels. Also in a perinatal study no effects were seen at levels up to 50000 ppm.
- Positive control:
- None.
- Parental animals: Observations and examinations:
- Animals were observed daily. Once per week they were removed from their cages and given a detailed assessment. Body weights were recorded weekly. After successful mating, body weights of the females were determined on day 0, 4, 7, 10, 14, and 20 p.c. as well as day 0, 4, 7, 14, and 21 p.p. Food consumption was recorded weekly. After successful mating, food consumption of the females were determined on day 0, 4, 7, 10, 14, and 20 p.c. as well as day 0, 4, 7, 14, and 21 p.p.
- Oestrous cyclicity (parental animals):
- Since the investigaion of precoital time in the F0 animals did not indicate a substance-induced effect, oestrus stages were not determined in the F1 generation in order to prevent pseudopregnancies.
- Sperm parameters (parental animals):
- Sperm analysis was preformed using the right cauda epididymis collected immediately after sacrifice. The number of cauda epididymal sperm reserves was determined in a sample of the stock solution using a Makler cell counting chamber. The percent motile sperm was estimated by assessing 20 sperm using a microscope. A morphological evaluation of an epididymal sperm sample was preformed by investigating 200 sperm under the microscope.
- Litter observations:
- STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: [yes]
- If yes, maximum of 8 pups/litter (4/sex/litter as close as possible); excess pups were killed and discarded.
PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring: number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities, locomotor activity using the ActiMot/Motitest computerised light beam system. Between day 30 and 60 learning and memory was tested using an M water maze.
GROSS EXAMINATION OF DEAD PUPS:
Necropsy was performed in all pups not selected for postweaning investigations or found dead during the study. - Postmortem examinations (parental animals):
- Necropsy was preformed on all females after weaning of offspring, in animals found dead or sacrificed in moribund condition and in all males and females on successfully mated. The number of implantation sites was determined using ammonium sulfide staining were there were no visible implantations. Organ weights were determined for: uterus, ovaries, testes, epididymides, seminal vessels, prostrate, liver, kidneys, adrenal glands, spleen, heart and lungs. In females organ weights were measured only in females that had pups surviving until day 21 p.p. Histopathological examination was performed on control and 50000 ppm exposure group animals. The following tissues were examined: vagina, uterus, oviducts, cervix, ovaries, testes one epididymis, seminal vessels, prostate, coagulating glands, brain, heart kidneys, liver, lungs.
- Postmortem examinations (offspring):
- F1 pups: Gross pathology was performed on organs that appeared to be normal. In addition, the following organs were selected from one male and one female of each litter: heart, kidneys, liver and lungs. The following organs and tissues were investigated histopathologically from one and one female of each litter: heart, kidneys, liver and lungs.
F2 pups: Gross pathology was performed on organs that appeared to be normal. In addition, the following organs were selected from one male and one female of each litter: heart, kidneys, liver, lungs and brain. The following organs and tissues were investigated histopathologically from one and one female of each litter: heart, kidneys, liver and lungs. - Statistics:
- All data were recorded by the on-line data aquisition system (Toxicology Analysis System), PROVANTIS 5.0.1, PLACES 2000.1.8 or on special sheets. Statistical evaluation was conducted at p = 0.05. Body weights and food consumption were analyzed using analysis of variance. If differences were noted, the treatment groups were compared to controls using Dunnets modification of the t-test. Kruskall-Wallis ANOVA and Mann-Whitney U-test were applied in the case of non-normal data. Organ weights were compared using the Dunnett's modification of the t-test. Qualitative data were analyzed using the two-tailed FISHER test with Bonferroni correction or Chi-square test.
- Reproductive indices:
- Time to mating, number of successul matings, litter size and survival were determined. Oestrus cycle was determined in F0 animals only.
- Offspring viability indices:
- Survival, body weight and body weight gain, sex ratios, learning and memory were measured.
- Clinical signs:
- no effects observed
- Dermal irritation (if dermal study):
- not examined
- Mortality:
- mortality observed, treatment-related
- Description (incidence):
- Mortality of lactating dams in the medium and high dose group was observed begining with day 10 of lactation. The following numbers of animals were found dead or had to be killed in moribound condition - expressed as mortality per number of animals with liveborn offpsring: 0/22 in the control group, 0/21 in the low dose group, 2/21 in the medium dose group and 12/25 in the high dose group. In most cases, animals were within normal limits after the last exposure, but found dead the next morning.
- Body weight and weight changes:
- effects observed, treatment-related
- Description (incidence and severity):
- In males, there was a statistically significant decrease in body weight of the high dose group compared to the control group at the beginning of exposure (day 7 and 14) and during the first weeks of mating (day 77 to 91), accompanied by a decrease in body weight gain between days 0 and 7 as well as day 70 and 77. This was followed by an incrase in body weight gain between days 91 and 98 in the high dose group. The total weight gain between days 0 and 70 was decreased in the high dose group. In females, body weight gain was decreased between days 4 and 7 p.p. as well as during the whole period of lactation.
- 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:
- not examined
- Clinical biochemistry findings:
- not examined
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- not examined
- Immunological findings:
- not examined
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Description (incidence and severity):
- A significant increase in histopathological changes were seen in the cerebellum of 9/27 female rats in the high level group. A similar finding occurred in 1/30 female rats in the medium dose. Also 5/28 female rats in the high level group showed lesions in the cerebrum. No brain lesions were seen in male or non-pregnant female animals.
- Histopathological findings: non-neoplastic:
- effects observed, treatment-related
- Description (incidence and severity):
- Myocarditis was seen in both male and female rats: 3/30 (male, air control), 3/30 (male, medium level) and 15/30 (male, high level) as well as 1/30 (female, air control), 0/30 (female, medium level) and 6/30 (female, high level). Thus the findings in the medium level were similar to the air control, while the increase in the high level could be related to the exposure to HFC-245fa. Moderate to severe congestion was reported in the liver (10/30) and kidneys (11/30) in the high level exposure female rats. As the liver and kidney findings occurred only in animals that had died during the study and were present in all animals that died except for one dying on the last day, they appear to be agonal in nature and unrelated to the test compound exposure. All other lesions were judged to be incidental.
- Histopathological findings: neoplastic:
- no effects observed
- Other effects:
- not examined
- Reproductive function: oestrous cycle:
- not examined
- Reproductive function: sperm measures:
- effects observed, treatment-related
- Description (incidence and severity):
- Sperm motility was significantly decreased in the high dose group with the same (statistically not significant) in the medium dose group. There was a trend towards a decrease in F0 sperm count in the medium and high dose group which, however, was not statistically significant in the single group comparisons with the control.
- Reproductive performance:
- no effects observed
- Key result
- Dose descriptor:
- NOAEC
- Effect level:
- 2 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- clinical signs
- mortality
- body weight and weight gain
- neuropathology
- histopathology: non-neoplastic
- reproductive function (sperm measures)
- Key result
- Critical effects observed:
- yes
- Lowest effective dose / conc.:
- 10 000 ppm
- System:
- cardiovascular
- Organ:
- brain
- heart
- kidney
- liver
- Treatment related:
- yes
- Dose response relationship:
- yes
- Relevant for humans:
- yes
- Clinical signs:
- no effects observed
- Dermal irritation (if dermal study):
- not examined
- Mortality:
- mortality observed, treatment-related
- Description (incidence):
- A pattern of mortality similar to that seen in the F0 dams was seen in the F1 dams beginning on the 12 day of lactation, 0/18 (controls), 0/23 (low level), 2/23 (medium level) and 6/13 (high level) exposure groups. As noted above, these animals appeared normal at the end of the day and were found dead the following morning.
- Body weight and weight changes:
- effects observed, treatment-related
- Description (incidence and severity):
- In the high dose group there was a decreased body weight at the begining of exposure after weaning in females. This difference disappeared during exposure and a statistically significantly increased body weight gain was seen in females between days 7 and 14 of treatment as well as over the whole premating period. In males, the same trend was observed, with statistically significantly increased body weight gains in the high dose group.
- Food consumption and compound intake (if feeding study):
- effects observed, treatment-related
- Description (incidence and severity):
- There was a slight, but statistically significant, decrease in food consumption in females of the high dose group at the begining of exposure (day 0-7 and 14-21).
- Food efficiency:
- not examined
- Water consumption and compound intake (if drinking water study):
- not examined
- Ophthalmological findings:
- not examined
- Haematological findings:
- not examined
- Clinical biochemistry findings:
- no effects observed
- Endocrine findings:
- not examined
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- no effects observed
- Immunological findings:
- not examined
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Gross pathological findings:
- no effects observed
- Neuropathological findings:
- effects observed, treatment-related
- Description (incidence and severity):
- Statistically significant substance-related histopathological changes were observed in the cerebellum of 10 females of the high dose group. Very severe multifocal malacia was detected in 5 females. Moderate multifocal neuronal degeneration (in one animal with necrosis) in the cerebellar cortex accompanied by a moderate sponigiosis was diagnosed in 2 other females. In the medium dose group, 1 female with very slight focal pervascular haemorrhages in the cerebellar cortex was seen. No such findings were observed in the control animals.
- Histopathological findings: non-neoplastic:
- no effects observed
- Histopathological findings: neoplastic:
- not examined
- Other effects:
- not specified
- Reproductive function: oestrous cycle:
- not examined
- Reproductive function: sperm measures:
- no effects observed
- Description (incidence and severity):
- There was a trend towards a decrease in F1 sperm count in the high dose group, which, however, was not statistically significant. The percentage of abnormal sperm was decreased in all substance-treatment groups, but this was not considered an adverse effect.
- Reproductive performance:
- no effects observed
- Key result
- Dose descriptor:
- NOAEC
- Effect level:
- 10 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- mortality
- neuropathology
- Key result
- Critical effects observed:
- yes
- Lowest effective dose / conc.:
- 50 000 ppm
- System:
- central nervous system
- Organ:
- brain
- Treatment related:
- yes
- Dose response relationship:
- yes
- Relevant for humans:
- yes
- Clinical signs:
- no effects observed
- Dermal irritation (if dermal study):
- not examined
- Mortality / viability:
- mortality observed, non-treatment-related
- Description (incidence and severity):
- There was a statistically significant decrease in average litter size in the medium and high dose group in the late lactation period. Some of this decrease in the high dose group could be attributed to maternal mortality in that group and therefore not attributed to treatment.
- Body weight and weight changes:
- effects observed, treatment-related
- Description (incidence and severity):
- There was a significant decrease in pup weight in the high dose group compared to controls beginning with day 14 p.p.
- 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:
- not examined
- Clinical biochemistry findings:
- not examined
- Urinalysis findings:
- not examined
- Sexual maturation:
- no effects observed
- Anogenital distance (AGD):
- not examined
- Nipple retention in male pups:
- not examined
- Organ weight findings including organ / body weight ratios:
- effects observed, treatment-related
- Description (incidence and severity):
- In the high dose group, all organ weights were decreased compared to the control group. This reached statistical significance in males for heart and lung, and in females for ovaries, kidneys, liver, heart and lungs. This also occurred in the heart of females of the medium dose group. This decrease could be a result of the lower terminal body weight of the pups in the high dose group.
- Gross pathological findings:
- no effects observed
- Histopathological findings:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Findings in the heart and kidney were equally divided in the control and high level groups. There were no other reported findings.
- Other effects:
- no effects observed
- Behaviour (functional findings):
- not examined
- Developmental immunotoxicity:
- not examined
- Key result
- Dose descriptor:
- NOAEC
- Generation:
- F1
- Effect level:
- 10 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- body weight and weight gain
- organ weights and organ / body weight ratios
- Key result
- Critical effects observed:
- no
- Clinical signs:
- no effects observed
- Dermal irritation (if dermal study):
- not examined
- Mortality / viability:
- mortality observed, treatment-related
- Description (incidence and severity):
- There was a statistically significant increase in the number of still born pups in the low and high level groups, but not the medium level. When the incidence of stillborn pups is combined with the incidence of pups not surviving until day 4, the incidence in the control, low and medium level groups is comparable. Thus it would appear that the increase in still born pups and pups not surviving until day 4 was only associated with the high exposure level group.
- Body weight and weight changes:
- not specified
- Food consumption and compound intake (if feeding study):
- no effects observed
- Food efficiency:
- not specified
- Water consumption and compound intake (if drinking water study):
- not specified
- Ophthalmological findings:
- not examined
- Haematological findings:
- not examined
- Clinical biochemistry findings:
- not examined
- Urinalysis findings:
- not examined
- Sexual maturation:
- not examined
- Anogenital distance (AGD):
- not examined
- Nipple retention in male pups:
- not examined
- Organ weight findings including organ / body weight ratios:
- effects observed, treatment-related
- Description (incidence and severity):
- In the high level group, the right (but not left) testes was increased in weight in the males and the uterus and heart weight was increased in females. All other organ weights were normal.
- Gross pathological findings:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Sporadically occurring findings in F2 weanling gross pathology included dark red areas in the lung, spongy condition of the lung, and ovarial cysts. There were no statistically significant differences to the control group. Consequently, none of these findings were considered substance-related.
- Histopathological findings:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Very slight and slight chronic progressive nephropathy was diagnosed in rats of the control, medium dose and high dose group.
- Other effects:
- no effects observed
- Behaviour (functional findings):
- not examined
- Developmental immunotoxicity:
- not examined
- Key result
- Dose descriptor:
- NOAEC
- Generation:
- F2
- Effect level:
- 10 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- mortality
- organ weights and organ / body weight ratios
- Key result
- Critical effects observed:
- no
- Key result
- Reproductive effects observed:
- yes
- Lowest effective dose / conc.:
- 10 000 ppm
- Treatment related:
- yes
- Relation to other toxic effects:
- reproductive effects occurring together with other toxic effects, but not as a secondary non-specific consequence of other toxic effects
- Dose response relationship:
- yes
- Relevant for humans:
- yes
- Conclusions:
- In a 2-generation, inhalation, reproduction study conducted in Sprague-Dawley rats the NOAEC was identified to be 2000 ppm based on mortality in several dams in the medium and high level exposure group of the P0 and F1 generation. There was an increase in abnormal findings in the brain and heart that appear to be related to exposure to HFC-245fa seen predominately in the high level exposure group. Brain lesions were not seen in males or non-pregnant females. There was an increase in the number of still-born pups combined with pups not surviving until Day 4 pp in the high level exposure group of the F2 generation. A decrease in sperm motility was found in the high dose males of the F0 generation.
- Executive summary:
A 2-generation, inhalation, reproduction study was conducted in Sprague-Dawley rats at exposure levels of 0, 2,000, 10,000 and 50,000 ppm. Several of the dams in the high level exposure group died during the late period of lactation. There were also a few similar deaths in the medium level exposure group, but not in the controls or low level groups. There was an increase in abnormal findings in the brain and heart that appear to be related to exposure to HFC-245fa. And while seen predominately in the high level exposure group, 1 rat in the F0 and one rat in the F1 generation also had similar brain lesions. Brain lesions were not seen in males or non-pregnant females. Finally, in the F2 generation, there was an increase in the number of still-borne pups combined with pups not surviving until Day 4 p.p. in the high level exposure group. While there was a decrease in sperm motility in the high level males of the F0 generation, this effect was not seen in the F1 generation and thus may be spurious. Exposure at 2000 ppm did not appear to result in any adverse effects and while the exposure at 10,000 ppm did result in some effects, they were far less numerous than seen at 50,000 ppm, suggesting that this was close to the threshold.
- Endpoint:
- two-generation reproductive toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- guideline study
- Remarks:
- Read-across to K1 study therefore K2 is the maximum Klimisch value.
- Justification for type of information:
- Read-across approach - see read-across justification in section 13.
- Principles of method if other than guideline:
- The study described in this report was conducted following the reproductive study guidelines as described in U.S. EPA Health Effects Test Guidelines OPPTS 870.3800 Reproduction and Fertility Effects (August 1998) and OECD Guideline 416 Two-Generation Reproduction Toxicity Study (January 2001) and in compliance with the Principles of Good Laboratory Practice (German Chemicals Law § 19a, Appendix 1, pp. 2119 2129, BGB1. I, June 28, 2002) and German Animal Protection Law (Tierschutzgesetz) of May 25, 1998.
- GLP compliance:
- yes
- Limit test:
- no
- Justification for study design:
- The dose levels were based on the results of a 13-week study conducted with doses of 0, 500, 2000, 10000 and 50000 ppm of the substance. The nose-only inhalation was chosen since a whole-body inhalation exposure was incompatbile with German legislation due to the high amount of substance released.
- Specific details on test material used for the study:
- SOURCE OF TEST MATERIAL
- Lot/batch number of test material: 0050404064004
- Species:
- rat
- Strain:
- Sprague-Dawley
- Details on species / strain selection:
- Hsd:Sprague Dawley SDr
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- Sprague Dawley rats approximately 4 weeks old were obtained from Harlan Winkelmann. They were acclimated to the exposure tubes for 3 weeks prior to treatment. Each animal was given a unique number. They were housed individually in polycarbonate cages type III. They were fed 1314 N specially prepared pelleted chow from Altromin International, Lage, Germany, ad libitum. Fresh tap water was provided ad libitum in 300 ml polycarbonate bottles and changed weekly. The temperature in the animal room was maintained at 20-24°C and the rel. humidity 40-70%. The lighting in the animal housing room was maintained on a 12 hr light/dark cycle.
- Route of administration:
- inhalation
- Type of inhalation exposure (if applicable):
- nose/head only
- Vehicle:
- unchanged (no vehicle)
- Details on exposure:
- Method of administration or exposure: Nose only administration. The exposures were conducted in four identical oro-nasal exposure chambers of cylindrical shape with four levels, each housing 16 rats. Rats were placed around the chambers in tapered acrylic glass tubes with adjustable back stops. The exposure cylinder was operated at a slightly positive pressure. The exposure atmosphere was generated by injecting a defined mass flow of HFC-245fa into a constant air flow.. The air flow rates were controlled by mass flow meters.
- Details on mating procedure:
- Animals were mated beginning after 10 weeks of exposure for four consecutive weeks or until successful mating as indicated by the presence of sperm or a vaginal plug. Over night mating was preformed with one male and one female from the same treatment group. The time to successful insemination (precoital time) was recorded.
- Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- The HFC-245fa concentration was measured using a flame ionization detector (FID). For the FID measurement, the test and control atmospheres were sampled every 10 min. The FID was calibrated against n-butane so drifts in the detector could easily be detected. The exposure levels of HFC-245fa were determined by comparison to the n-butane signals based on a calabration curve.
- Duration of treatment / exposure:
- Exposures were 4 hours per day
- Frequency of treatment:
- Duration of exposure per day: 4 hours
Dosing regime P0: 7 days/week (males)
Dosing regime P0: 7 days/week (females)
Dosing regime F1: 7 days/week (males)
Dosing regime F1: 7 days/week (females) - Details on study schedule:
- F0 animals were exposed for 10 weeks prior to mating and during the mating period. After successful mating, females were exposed daily from day 0 to day 20 post-conception (p.c.) as well as from day 5 post partum (p.p.) to day 20 p.p. Daily exposure of animals not successfully mated was continued until sacrifice. After completion of weaning on day 21 p.p., F1 animals were trained to the tubes for 2-3 weeks. Daily exposure of the F1 animals started thereafter and lasted 10 weeks before mating and during mating. Females were exposed daily from day 0 to day 20 p.c. as well as from day 5 to day 20 p.p. Daily treatment of males and females not successfully mated was continued until their sacrifice.
- Dose / conc.:
- 0 ppm
- Dose / conc.:
- 2 000 ppm
- Dose / conc.:
- 10 000 ppm
- Dose / conc.:
- 50 000 ppm
- No. of animals per sex per dose:
- 30 males and 30 females except for top dose F1 which had 27 males and 27 females.
- Control animals:
- yes, sham-exposed
- Details on study design:
- Exposure levels were based on a previous 13 week inhalation toxicity study that was conducted at levels of 0, 500, 2000, 10000 and 50000 ppm.The main finding was myocarditis in most animals in the 10000 and 50000 ppm groups. No effects were seen at the lower levels. Also in a perinatal study no effects were seen at levels up to 50000 ppm.
- Positive control:
- None.
- Parental animals: Observations and examinations:
- Animals were observed daily. Once per week they were removed from their cages and given a detailed assessment. Body weights were recorded weekly. After successful mating, body weights of the females were determined on day 0, 4, 7, 10, 14, and 20 p.c. as well as day 0, 4, 7, 14, and 21 p.p. Food consumption was recorded weekly. After successful mating, food consumption of the females were determined on day 0, 4, 7, 10, 14, and 20 p.c. as well as day 0, 4, 7, 14, and 21 p.p.
- Oestrous cyclicity (parental animals):
- Since the investigaion of precoital time in the F0 animals did not indicate a substance-induced effect, oestrus stages were not determined in the F1 generation in order to prevent pseudopregnancies.
- Sperm parameters (parental animals):
- Sperm analysis was preformed using the right cauda epididymis collected immediately after sacrifice. The number of cauda epididymal sperm reserves was determined in a sample of the stock solution using a Makler cell counting chamber. The percent motile sperm was estimated by assessing 20 sperm using a microscope. A morphological evaluation of an epididymal sperm sample was preformed by investigating 200 sperm under the microscope.
- Litter observations:
- STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: [yes]
- If yes, maximum of 8 pups/litter (4/sex/litter as close as possible); excess pups were killed and discarded.
PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring: number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities, locomotor activity using the ActiMot/Motitest computerised light beam system. Between day 30 and 60 learning and memory was tested using an M water maze.
GROSS EXAMINATION OF DEAD PUPS:
Necropsy was performed in all pups not selected for postweaning investigations or found dead during the study. - Postmortem examinations (parental animals):
- Necropsy was preformed on all females after weaning of offspring, in animals found dead or sacrificed in moribund condition and in all males and females on successfully mated. The number of implantation sites was determined using ammonium sulfide staining were there were no visible implantations. Organ weights were determined for: uterus, ovaries, testes, epididymides, seminal vessels, prostrate, liver, kidneys, adrenal glands, spleen, heart and lungs. In females organ weights were measured only in females that had pups surviving until day 21 p.p. Histopathological examination was performed on control and 50000 ppm exposure group animals. The following tissues were examined: vagina, uterus, oviducts, cervix, ovaries, testes one epididymis, seminal vessels, prostate, coagulating glands, brain, heart kidneys, liver, lungs.
- Postmortem examinations (offspring):
- F1 pups: Gross pathology was performed on organs that appeared to be normal. In addition, the following organs were selected from one male and one female of each litter: heart, kidneys, liver and lungs. The following organs and tissues were investigated histopathologically from one and one female of each litter: heart, kidneys, liver and lungs.
F2 pups: Gross pathology was performed on organs that appeared to be normal. In addition, the following organs were selected from one male and one female of each litter: heart, kidneys, liver, lungs and brain. The following organs and tissues were investigated histopathologically from one and one female of each litter: heart, kidneys, liver and lungs. - Statistics:
- All data were recorded by the on-line data aquisition system (Toxicology Analysis System), PROVANTIS 5.0.1, PLACES 2000.1.8 or on special sheets. Statistical evaluation was conducted at p = 0.05. Body weights and food consumption were analyzed using analysis of variance. If differences were noted, the treatment groups were compared to controls using Dunnets modification of the t-test. Kruskall-Wallis ANOVA and Mann-Whitney U-test were applied in the case of non-normal data. Organ weights were compared using the Dunnett's modification of the t-test. Qualitative data were analyzed using the two-tailed FISHER test with Bonferroni correction or Chi-square test.
- Reproductive indices:
- Time to mating, number of successul matings, litter size and survival were determined. Oestrus cycle was determined in F0 animals only.
- Offspring viability indices:
- Survival, body weight and body weight gain, sex ratios, learning and memory were measured.
- Clinical signs:
- no effects observed
- Dermal irritation (if dermal study):
- not examined
- Mortality:
- mortality observed, treatment-related
- Description (incidence):
- Mortality of lactating dams in the medium and high dose group was observed begining with day 10 of lactation. The following numbers of animals were found dead or had to be killed in morbound condition - expressed as mortality per number of animals with liveborn offpsring: 0/22 in the control group, 0/21 in the low dose group, 2/21 in the medium dose group and 12/25 in the high dose group. In most cases, animals were within normal limits after the last exposure, but found dead the next morning.
- Body weight and weight changes:
- effects observed, treatment-related
- Description (incidence and severity):
- In males, there was a statistically significant decrease in body weight of the high dose group compared to the control group at the beginning of exposure (day 7 and 14) and during the first weeks of mating (day 77 to 91), accompanied by a decrease in body weight gain between days 0 and 7 as well as day 70 and 77. This was followed by an incrase in body weight gain between days 91 and 98 in the high dose group. The total weight gain between days 0 and 70 was decreased in the high dose group. In females, body weight gain was decreased between days 4 and 7 p.p. as well as during the whole period of lactation.
- 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:
- not examined
- Clinical biochemistry findings:
- not examined
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- not examined
- Immunological findings:
- not examined
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Description (incidence and severity):
- A significant increase in histopathological changes were seen in the cerebellum of 9/27 female rats in the high level group. A similar finding occurred in 1/30 female rats in the medium dose. Also 5/28 female rats in the high level group showed lesions in the cerebrum. No brain lesions were seen in male or non-pregnant female animals.
- Histopathological findings: non-neoplastic:
- effects observed, treatment-related
- Description (incidence and severity):
- Myocarditis was seen in both male and female rats: 3/30 (male, air control), 3/30 (male, medium level) and 15/30 (male, high level) as well as 1/30 (female, air control), 0/30 (female, medium level) and 6/30 (female, high level). Thus the findings in the medium level were similar to the air control, while the increase in the high level could be related to the exposure to HFC-245fa. Moderate to severe congestion was reported in the liver (10/30) and kidneys (11/30) in the high level exposure female rats. As the liver and kidney findings occurred only in animals that had died during the study and were present in all animals that died except for one dying on the last day, they appear to be agonal in nature and unrelated to the test compound exposure. All other lesions were judged to be incidental.
- Histopathological findings: neoplastic:
- no effects observed
- Other effects:
- not examined
- Reproductive function: oestrous cycle:
- not examined
- Reproductive function: sperm measures:
- effects observed, treatment-related
- Description (incidence and severity):
- Sperm motility was significantly decreased in the high dose group with the same (statistically not significant) in the medium dose group. There was a trend towards a decrease in F0 sperm count in the medium and high dose group which, however, was not statistically significant in the single group comparisons with the control.
- Reproductive performance:
- no effects observed
- Key result
- Dose descriptor:
- NOAEC
- Effect level:
- 2 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- clinical signs
- mortality
- body weight and weight gain
- neuropathology
- histopathology: non-neoplastic
- reproductive function (sperm measures)
- Key result
- Critical effects observed:
- yes
- Lowest effective dose / conc.:
- 10 000 ppm
- System:
- cardiovascular
- Organ:
- brain
- heart
- kidney
- liver
- Treatment related:
- yes
- Dose response relationship:
- yes
- Relevant for humans:
- yes
- Clinical signs:
- no effects observed
- Dermal irritation (if dermal study):
- not examined
- Mortality:
- mortality observed, treatment-related
- Description (incidence):
- A pattern of mortality similar to that seen in the F0 dams was seen in the F1 dams beginning on the 12 day of lactation, 0/18 (controls), 0/23 (low level), 2/23 (medium level) and 6/13 (high level) exposure groups. As noted above, these animals appeared normal at the end of the day and were found dead the following morning.
- Body weight and weight changes:
- effects observed, treatment-related
- Description (incidence and severity):
- In the high dose group there was a decreased body weight at the begining of exposure after weaning in females. This difference disappeared during exposure and a statistically significantly increased body weight gain was seen in females between days 7 and 14 of treatment as well as over the whole premating period. In males, the same trend was observed, with statistically significantly increased body weight gains in the high dose group.
- Food consumption and compound intake (if feeding study):
- effects observed, treatment-related
- Description (incidence and severity):
- There was a slight, but statistically significant, decrease in food consumption in females of the high dose group at the begining of exposure (day 0-7 and 14-21).
- Food efficiency:
- not examined
- Water consumption and compound intake (if drinking water study):
- not examined
- Ophthalmological findings:
- not examined
- Haematological findings:
- not examined
- Clinical biochemistry findings:
- no effects observed
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- no effects observed
- Immunological findings:
- not examined
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Gross pathological findings:
- no effects observed
- Neuropathological findings:
- effects observed, treatment-related
- Description (incidence and severity):
- Statistically significant substance-related histopathological changes were observed in the cerebellum of 10 females of the high dose group. Very severe multifocal malacia was detected in 5 females. Moderate multifocal neuronal degeneration (in one animal with necrosis) in the cerebellar cortex accompanied by a moderate sponigiosis was diagnosed in 2 other females. In the medium dose group, 1 female with very slight focal pervascular haemorrhages in the cerebellar cortex was seen. No such findings were observed in the control animals.
- Histopathological findings: non-neoplastic:
- no effects observed
- Histopathological findings: neoplastic:
- not examined
- Other effects:
- not specified
- Reproductive function: oestrous cycle:
- not examined
- Reproductive function: sperm measures:
- no effects observed
- Description (incidence and severity):
- There was a trend towards a decrease in F1 sperm count in the high dose group, which, however, was not statistically significant. The percentage of abnormal sperm was decreased in all substance-treatment groups, but this was not considered an adverse effect.
- Reproductive performance:
- no effects observed
- Key result
- Dose descriptor:
- NOAEC
- Effect level:
- 10 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- mortality
- neuropathology
- Key result
- Critical effects observed:
- yes
- Lowest effective dose / conc.:
- 50 000 ppm
- System:
- central nervous system
- Organ:
- brain
- Treatment related:
- yes
- Dose response relationship:
- yes
- Relevant for humans:
- yes
- Clinical signs:
- no effects observed
- Dermal irritation (if dermal study):
- not examined
- Mortality / viability:
- mortality observed, non-treatment-related
- Description (incidence and severity):
- There was a statistically significant decrease in average litter size in the medium and high dose group in the late lactation period. Some of this decrease in the high dose group could be attributed to maternal mortality in that group and therefore not attributed to treatment.
- Body weight and weight changes:
- effects observed, treatment-related
- Description (incidence and severity):
- There was a significant decrease in pup weight in the high dose group compared to controls begining with day 14 p.p.
- 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:
- not examined
- Clinical biochemistry findings:
- not examined
- Urinalysis findings:
- not examined
- Sexual maturation:
- no effects observed
- Anogenital distance (AGD):
- not examined
- Nipple retention in male pups:
- not examined
- Organ weight findings including organ / body weight ratios:
- effects observed, treatment-related
- Description (incidence and severity):
- In the high dose group, all organ weights were decreased compared to the control group. This reached statistical significance in males for heart and lung, and in females for ovaries, kidneys, liver, heart and lungs. This also occurred in the heart of females of the medium dose group. This decrease could be a result of the lower terminal body weight of the pups in the high dose group.
- Gross pathological findings:
- no effects observed
- Histopathological findings:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Findings in the heart and kidney were equally divided in the control and high level groups. There were no other reported findings.
- Other effects:
- no effects observed
- Behaviour (functional findings):
- not examined
- Developmental immunotoxicity:
- not examined
- Key result
- Dose descriptor:
- NOAEC
- Generation:
- F1
- Effect level:
- 10 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- body weight and weight gain
- organ weights and organ / body weight ratios
- Key result
- Critical effects observed:
- no
- Clinical signs:
- no effects observed
- Dermal irritation (if dermal study):
- not examined
- Mortality / viability:
- mortality observed, treatment-related
- Description (incidence and severity):
- There was a statistically significant increase in the number of still born pups in the low and high level groups, but not the medium level. When the incidence of stillborn pups is combined with the incidence of pups not surviving until day 4, the incidence in the control, low and medium level groups is comparable. Thus it would appear that the increase in still born pups and pups not surviving until day 4 was only associated with the high exposure level group.
- Body weight and weight changes:
- not specified
- Food consumption and compound intake (if feeding study):
- no effects observed
- Food efficiency:
- not specified
- Water consumption and compound intake (if drinking water study):
- not specified
- Ophthalmological findings:
- not examined
- Haematological findings:
- not examined
- Clinical biochemistry findings:
- not examined
- Urinalysis findings:
- not examined
- Sexual maturation:
- not examined
- Anogenital distance (AGD):
- not examined
- Nipple retention in male pups:
- not examined
- Organ weight findings including organ / body weight ratios:
- effects observed, treatment-related
- Description (incidence and severity):
- In the high level group, the right (but not left) testes was increased in weight in the males and the uterus and heart weight was increased in females. All other organ weights were normal.
- Gross pathological findings:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Sporadically occurring findings in F2 weanling gross pathology included dark red areas in the lung, spongy condition of the lung, and ovarial cysts. There were no statistically significant differences to the control group. Consequently, none of these findings were considered substance-related.
- Histopathological findings:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Very slight and slight chronic progressive nephropathy was diagnosed in rats of the control, medium dose and high dose group.
- Other effects:
- no effects observed
- Behaviour (functional findings):
- not examined
- Developmental immunotoxicity:
- not examined
- Key result
- Dose descriptor:
- NOAEC
- Generation:
- F2
- Effect level:
- 10 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- mortality
- organ weights and organ / body weight ratios
- Key result
- Critical effects observed:
- no
- Key result
- Reproductive effects observed:
- yes
- Lowest effective dose / conc.:
- 10 000 ppm
- Treatment related:
- yes
- Relation to other toxic effects:
- reproductive effects occurring together with other toxic effects, but not as a secondary non-specific consequence of other toxic effects
- Dose response relationship:
- yes
- Relevant for humans:
- yes
- Conclusions:
- In a 2-generation, inhalation, reproduction study conducted in Sprague-Dawley rats the NOAEC was identified to be 2000 ppm based on mortality in several dams in the medium and high level exposure group of the P0 and F1 generation. There was an increase in abnormal findings in the brain and heart that appear to be related to exposure to HFC-245fa seen predominately in the high level exposure group. Brain lesions were not seen in males or non-pregnant females. There was an increase in the number of still-born pups combined with pups not surviving until Day 4 pp in the high level exposure group of the F2 generation. A decrease in sperm motility was found in the high dose males of the F0 generation.
- Executive summary:
A 2-generation, inhalation, reproduction study was conducted in Sprague-Dawley rats at exposure levels of 0, 2,000, 10,000 and 50,000 ppm. Several of the dams in the high level exposure group died during the late period of lactation. There were also a few similar deaths in the medium level exposure group, but not in the controls or low level groups. There was an increase in abnormal findings in the brain and heart that appear to be related to exposure to HFC-245fa. And while seen predominately in the high level exposure group, 1 rat in the F0 and one rat in the F1 generation also had similar brain lesions. Brain lesions were not seen in males or non-pregnant females. Finally, in the F2 generation, there was an increase in the number of still-borne pups combined with pups not surviving until Day 4 p.p. in the high level exposure group. While there was a decrease in sperm motility in the high level males of the F0 generation, this effect was not seen in the F1 generation and thus may be spurious. Exposure at 2000 ppm did not appear to result in any adverse effects and while the exposure at 10,000 ppm did result in some effects, they were far less numerous than seen at 50,000 ppm, suggesting that this was close to the threshold.
- Endpoint:
- two-generation reproductive toxicity
- Remarks:
- based on test type (migrated information)
- Type of information:
- migrated information: read-across based on grouping of substances (category approach)
- Adequacy of study:
- supporting study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: GLP guideline study not in accordance to OECD TG
- Principles of method if other than guideline:
- Pre-clinical safety evaluation for use of HFA 134a as a propellant in a MDI (metered dose inhaler). In the fertility study snout only inhalation techniques using a single 1 hour daily exposure regimen were used. HFA 134a was generated from MDI to evaluate the propellant delivered through a metering system similar to that used by patients.
- GLP compliance:
- yes
- Species:
- rat
- Strain:
- other: AHA - a strain of rat having both Sprague-Dawley and Wistar origins supplied from the Glaxo colony.
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- For the fertility study, males were within the weight range 177 – 233 g at Week 0 (the first week of treatment) and females were within the weight range 168 – 232 g at Week 6.
Animals were allowed to acclimatise to the experimental exposure conditions for at least two weeks. This included a period of acclimatisation to the exposure procedures. Animals were randomly allocated to treatment groups.
Food (Biosure Laboratory Animal Diet No.1 Special Diet Services Ltd. (Biosure), Manea, Cambridgeshire, UK) and tap water were provided ad libitum except during inhalation exposure and clinical procedures. Each animal was identified by an ear and/or foot tattoo.
The temperature and humidity generally remained within the ranges 21±3°C and 51±10% respectively, throughout the fertility study. A 12 hour light/dark photoperiod was provided. - Route of administration:
- inhalation
- Type of inhalation exposure (if applicable):
- nose only
- Vehicle:
- unchanged (no vehicle)
- Details on exposure:
- Each animal was exposed daily for a period of 1 hour in a snout-only exposure system. Animals were placed in individual restraining tubes, which were positioned in tiers radially around a snout-only exposure chamber (ADG Developments, Hitchin, Hertfordshire, UK). The inhalation system was designed to ensure a constant stream of fresh test material of uniform distribution at all chamber levels. The chamber was operated under dynamic airflow conditions of 20/l min. An electronically timed, pneumatically operated device was used to discharge HFA 134a from pressurised MDI into the top of the chamber. Waste vapour was drawn from the base of the chamber. The different exposure concentrations of test material were achieved by varying the number and rate of discharge of the MDI, which were weighed before and after exposure to estimate consumption.
- Details on mating procedure:
- Animals were mated one-to-one. Within treatment groups, pairing was random, except that the mating of siblings was avoided. During the pre-mating periods four or five animals of the same sex and treatment group were housed per cage. One male was kept with one female during mating. At the end of the mating period, males were replaced with their former cage mates and females were housed individually. Animals were housed in stainless steel cages with mesh floors although during mating, gestation and littering, solid floor polycarbonate breeding cages with sawdust bedding were used.
Oestrous cycles were monitored by means of vaginal lavage with cytology by light microscopy for 14 consecutive days prior to pairing. The stage of the cycle (dioestrous, pro-oestrous or oestrous) was recorded daily. Vaginal smears were examined daily during the mating period and mating was confirmed by the observation of spermatozoa in the smear. - Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- Samples were withdrawn daily from each inhalation chamber to assess the atmospheric concentration of HFA 134a gas, which was determined by specific gas chromatography using a flame ionisation detector. Quantification was by an external standard method.
- Duration of treatment / exposure:
- 10 weeks before pairing for males, 3 weeks before pairing for females, and during mating. F0 males were further exposed until week 18 of exposure and then killed. 14 of the pregnant F0 females from each group were further exposed until day 19 post coitum and terminated on day 20 post coitum for examination of their uterine contents and ovaries. The remaining F0 females were further exposed until day 20 post coitum, at which time exposures were supsended to allow parturition to occur. Exposure of these F0 females recommenced at the same concentrations on day 1 post partum until day 21 post partum, at which time the dams were terminated and the male and female F1 pups seperated.
- Frequency of treatment:
- 1 hour / day
- Details on study schedule:
- The fertility study comprised four groups, each consisting of 30 males and 30 females. The groups of rats received treatment as shown in Table 1. The dosed animals formed the parental (F0) generation and were treated throughout the periods of gametogenesis (10 weeks before pairing in males and 3 weeks before pairing in females) and mating. Males continued to be treated post mating, were killed in Week 18 and examined post mortem, whilst all mated females continued to be treated until their termination.
Fourteen of the pregnant females from each group were killed on Day 20 post coitum from examination of uterine contents and ovaries. Their treatment continued on Day 19. The remaining females were allowed to litter and rear their young (F1 generation). To allow parturition, dosing of these females was discontinued after dosing on Day 20 of pregnancy and recommenced on Day 1 post partum until Day 21 post partum. The dams were then killed and the male and female pups separated.
The survival, and physical and functional development of the F1 generation was assessed. On approximately Day 21 post partum, one animal of each sex was retained from each litter (12 litters/group) and raised to maturity. The remaining pups, together with their mothers, were killed and examined post mortem. The selected F1 rats were mated at approximately 70 days of age and survival and development of the resulting F2 progeny was monitored for 21 days post partum. F1 males failing to mate were examined post mortem. One F2 animal of each sex was retained from each litter (8 litters/group) and the remaining pups together with their mothers were killed and examined post mortem. Once F2 rats had attained sexual maturity they too were killed and examined post mortem. - Remarks:
- Doses / Concentrations:
0, 2595, 10080, 49308 ppm
Basis:
analytical conc. - No. of animals per sex per dose:
- 30/sex/group
- Control animals:
- yes, concurrent no treatment
- Details on study design:
- The maximum exposure concentrations were limited by the need to ensure adequate oxygenation (>19%) of the atmosphere and were based on findings from maximum tolerated dose studies in which rats were exposed to HFA 134a concentrations of up to 150 000 ppm. Low exposures were small multiples of the likely human exposure from drug administration from an MDI (33ppm hr/m2 lung surface area/day) and the intermediate exposures were the approximate geometric means of the high and low exposure concentrations.
Animals were randomly allocated to treatment groups. - Parental animals: Observations and examinations:
- Animals were inspected daily throughout the studies for any signs of ill health or reaction to treatment. Rats of each generation were weighed regularly through the study.
The quantity of food consumed by each cage of F0 rats was recorded weekly before and after mating. Group mean food consumption g/animal/week) was calculated.
Blood samples for analysis of HFA 134a concentration were collected by tail venepuncture into gas-tight vials during the last 15 minutes of exposure and 15 minutes after the completion of each exposure. Three F0 animals of each sex and treatment group were sampled during Week 15 (relative to the start of treatment) of the fertility study. The concentration of HFA 134a in whole blood samples was determined by gas chromatograph headspace analysis with flame ionisation detection. - Oestrous cyclicity (parental animals):
- Oestrous cycles were monitored by means of vaginal lavage with cytology by light microscopy for 14 consecutive days prior to pairing. The stage of the cycle (dioestrous, pro-oestrous or oestrous) was recorded daily.
- Sperm parameters (parental animals):
- Prostate, seminal vesicles, testes, epididymides, and pituitary were weighed and preserved only if the male in question had apparently failed to mate.
- Litter observations:
- Physical development of the F1 and F2 generations was assessed by noting the time at which certain events occurred. These events were pinna detachment, upper incisor eruption, eye opening, cleavage of the balanopreputial skinfold in males and vaginal opening (females). Similarly, the age at which certain reflexes (surface righting, startling response, air righting, and pupillary light reflexes) were attained in surviving offspring were recorded. In addition the eyes of all F1 offspring were examined by indirect ophthalmoscopy.
At 4 weeks of age, the locomotor co-ordination of offspring was tested using an accelerating rotarod. The time taken for each pup to lose balance was recorded. Spontaneous exploratory activity in an unfamiliar environment was measured at 5 weeks of age using the Actimat Doppler shift radar monitor. Learning, memory and reverse learning (relearning) were assessed between 7 to 9 weeks of age using the Biel maze. - Postmortem examinations (parental animals):
- Animals were killed by carbon dioxide asphyxiation. Routine post mortem examinations were carried out on all animals killed or found dead. They consisted of general macroscopic examination and preservation of samples of any apparently abnormal tissues.
In addition to routine post mortem examination, the uterus and ovaries of females killed on Day 20 of pregnancy (F0 and F1 generations) were removed entire, and the number of corpora lutea in each ovary was recorded. Upon removal of each uterus, the number of implantation sites, the positions of any foetuses, and of any apparent early or late intra-uterine deaths were recorded.
Uteri of apparently non-pregnant females were examined for evidence of implantation using a modified Salewski technique. Prostate, seminal vesicles, testes, epididymides, and pituitary were weighed and preserved only if the male in question had apparently failed to mate. - Postmortem examinations (offspring):
- All live foetuses were weighed, examined externally, and the sex and any abnormalities recorded. For the fertility study, half of the pups in each litter were fixed in 85% industrial methylated spirit for subsequent macroscopic examination and evisceration. They were later stained with Alizarin red S for skeletal examination (modified Dawson technique). The remaining pups of each litter were fixed in Bouins fluid for sectioning and visceral examination.
- Statistics:
- The group mean food consumption and body weight change of the adults and the litters were calculated for each day/occasion they were weighed. The change in group mean body weight of pregnant F0 females for each day of weighing was calculated with respect to the first day of treatment. Values for the F0 females during lactation, F0 and F1 females during pregnancy, were calculated with respect to the initial body weight recorded at the start of each relevant period.
Depending on the heterogeneity of variance between treatment groups, parametric (analysis of variance followed by Williams’ or t tests) or non-parametric (Kruskal-Wallis test) tests were used to analyse data.
Mean litter data and foetal abnormalities were analysed by the Kruskal-Wallis test. Intergroup comparisons were made by the non-parametric equivalent of the t test together with the Jonckheere test for an ordered series of treatments. Where 75% or more of the values for a given variable were the same, a Fischer’s exact test was used, with the Mantel-Haenszel test applied for analysing trend.
The rotarod data were analysed using an analysis of variance and the Actimat and Biel maze data by the Kruskal-Wallis test. Intergroup comparisons were made using the Williams test or the non-parametric equivalent, Shirley’s test.
Statistical analysis is declared at the 5% level and refers to differences between mean values for Group 1 and Groups 2,3 and 4. - Clinical signs:
- no effects observed
- Mortality:
- no mortality observed
- Body weight and weight changes:
- effects observed, treatment-related
- Food consumption and compound intake (if feeding study):
- effects observed, treatment-related
- Reproductive function: oestrous cycle:
- no effects observed
- Reproductive performance:
- no effects observed
- Key result
- Dose descriptor:
- NOEL
- Effect level:
- >= 50 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- clinical signs
- mortality
- body weight and weight gain
- food consumption and compound intake
- reproductive function (oestrous cycle)
- reproductive performance
- Remarks on result:
- not determinable due to absence of adverse toxic effects
- Clinical signs:
- no effects observed
- Mortality / viability:
- no mortality observed
- Body weight and weight changes:
- no effects observed
- Sexual maturation:
- no effects observed
- Gross pathological findings:
- no effects observed
- Key result
- Dose descriptor:
- NOEC
- Generation:
- F1
- Effect level:
- >= 50 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- viability
- body weight and weight gain
- gross pathology
- Remarks on result:
- not determinable due to absence of adverse toxic effects
- Key result
- Dose descriptor:
- NOEC
- Generation:
- F2
- Effect level:
- >= 50 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- mortality
- body weight and weight gain
- Key result
- Reproductive effects observed:
- no
- Lowest effective dose / conc.:
- 50 000 ppm
- Conclusions:
- There were no treatment-related effects on fertility, reproductive performance of rats treated with 1,1,1,2-tetrafluoroethane (HFA 134a) or on the development, maturation or reproductive performance of up to two sucessive generations. HFA 134a is judged not to be toxic to reproduction (fertility).
- Executive summary:
1,1,1,2 -tetrafluoroethane (HFA 134a) was administered to AHA rats by snout only inhalation to assess the effects on reproduction and development. In the fertility study (detailed above), rats were exposed to atmospheres of 2500, 10 000 or 50 000 ppm HFA 134a throughout gametogenesis, mating, pregnancy and lactation.
The only treatment related effect was a slight reduction in body weight gain of the treated parental generation at 50 000 ppm.
There were no adverse effects of HFA 134a on the fertility and reproductive performance of treated animals or on the development, maturation or reproductive performance of up to two successive generations.
- Endpoint:
- toxicity to reproduction
- Remarks:
- other: dominant lethal assay
- Type of information:
- migrated information: read-across based on grouping of substances (category approach)
- Adequacy of study:
- supporting study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: GLP Guidleline study
- Qualifier:
- according to guideline
- Guideline:
- other: Rodent dominant lethal assay, antifertility and germ cell mutation (equivalent or similar to OECD 478)
- Principles of method if other than guideline:
- Rodent dominant lethal study: antifertility and germ cell cell mutation assay.
- GLP compliance:
- yes
- Species:
- mouse
- Strain:
- CD-1
- Sex:
- male/female
- Route of administration:
- inhalation
- Vehicle:
- unchanged (no vehicle)
- Frequency of treatment:
- 6 hours /day for 5 days
- Remarks:
- Doses / Concentrations:
0, 1000, 10000, 50000 ppm
Basis: - No. of animals per sex per dose:
- 15 males / 30 Females
- Control animals:
- yes, concurrent no treatment
- Reproductive function: sperm measures:
- no effects observed
- Key result
- Dose descriptor:
- NOEL
- Effect level:
- 50 000 ppm
- Based on:
- test mat.
- Sex:
- male
- Basis for effect level:
- other: No effects on reproductive performance of male mice
- Dose descriptor:
- other:
- Remarks on result:
- not measured/tested
- Key result
- Reproductive effects observed:
- no
- Lowest effective dose / conc.:
- 50 000 ppm
- Conclusions:
- HFC 134a did not affect male fertility or cause mutagenic effects through sperm
- Executive summary:
In a dominant lethal assay, CD1 male mice were exposed to up to 50000 ppm HFC 134a for 5 days. After the last exposure, each male was housed with 2 virgin females for 4 consecutive nights. Further matings with new females were conducted at weekly intervals for a total of 8 times. The study indicated that HFC 134a did not affect male fertility or cause mutagenic effects through sperm.
- Endpoint:
- toxicity to reproduction
- Remarks:
- other: 13-week inhalation toxicity
- Type of information:
- experimental study
- Adequacy of study:
- supporting study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Citing results from the GLP 13 week inhalation toxicity study
- Qualifier:
- according to guideline
- Guideline:
- other: OECD Guideline 413
- Deviations:
- yes
- Remarks:
- an additional 10 rats/sex/level were included as post exposure groups
- GLP compliance:
- yes
- Species:
- rat
- Strain:
- Sprague-Dawley
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- Rats of 22 days of age were obtained from Charles River, Kingston, NY. They were quarantined for approx. 2 wks. The animal room was maintained at 23 +/- 2 deg C and 55 +/- 15% rel. humidity. Individual housing in wire mesh ss cages,
- Route of administration:
- inhalation: gas
- Type of inhalation exposure (if applicable):
- whole body
- Vehicle:
- air
- Details on exposure:
- Whole body exposures were conducted 6-hr/day, 5 days/wk. for 13 weeks in stainless steel and glass exposure units.
- Details on mating procedure:
- There was no mating
- Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- Gas samples (~0.1 ml) were analyzed with a Hewlett Packard 5880A GC with an FID. Samples were chromatographed on a 10 ft. by 1/8 inch ss column packed with 5% KRYTOX 60/80 Carbo Pack B. Samples were collected at approx. 30 min. intervals. Exposure levels were determined by comparing the detector response to a standard curve of the responses obtained with standard gas mixtures.
- Duration of treatment / exposure:
- Exposure levels were determined based on two previous 4-week studies that were conducted at exposure levels of 0, 2000, 10,000 and 39000 ppm. In the first study, exposures were conducted by the nose only route and effects were noted that were attributed to heat stress. In the second study, exposures were conducted by the whole body route and there were no apparent treatment related effects.
- Frequency of treatment:
- 6-hr/day, 5-days/wk for 13 wks
- Details on study schedule:
- 6-hr/day, 5-days/wk for 13 wks
- Remarks:
- Doses / Concentrations:
0, 2000, 10000, and 39000 ppm
Basis:
analytical conc. - No. of animals per sex per dose:
- 20
- Control animals:
- yes, sham-exposed
- Details on study design:
- Exposure levels were determined based on two previous 4-week studies that were conducted at exposure levels of 0, 2000, 10,000 and 39000 ppm.
- Positive control:
- none
- Parental animals: Observations and examinations:
- Rats were observed during the exposures, twice daily for health status on exposure days and once daily during non-exposure days. Body weights were measured and detailed clinical observations were conducted once per week. At the conclusion of the exposure period, a group of 10 rats/sex/level were observed for an additional 4 weeks. Food consumption was measured weekly. An ophthalmological exam was conducted prior to the first exposure and prior to the sacrifice at 13 weeks. Clinical laboratory, urinalysis and hematology evaluations were conducted at 45 and 90 days on 10 rats/sex/level. Rats were fasted for approx. 16 hrs prior to blood collection.
- Oestrous cyclicity (parental animals):
- Not measured in this study
- Sperm parameters (parental animals):
- Not measured in this study
- Litter observations:
- There was no mating
- Postmortem examinations (parental animals):
- All animals were given a gross necropsy examination, organ weights were measured on the spleen, heart, lungs, liver, kidneys, adrenals, testes, ovaries and brain, and tissues were collected from over 40 organs and fixed including reproductive organs. These were examined from the rats in the control and high exposure level from the rats sacrificed at 90 days. If any abnormalities were noted, those tissues would have been examined from the rats in the post exposure period and from the other exposure groups.
- Postmortem examinations (offspring):
- Not measured in this study,
- Statistics:
- Body wts., body wt. gains, organ wts., clinical laboratory and biochemical measurements were analyzed by a one-way analysis of varience. Additionally, the F-test, Dunnet's test, Bonferroni correction, Cochran-Armitage test, Bartlett's test Kruskal-Wallis test and Mann-Whitney U test were applied as appropriate.
- Reproductive indices:
- All reproductive organs from both male and female rats in the control and high exposure level groups were examined using normal fixation and H & Estain.
- Offspring viability indices:
- There were no offspring in this study
- Clinical signs:
- no effects observed
- Body weight and weight changes:
- no effects observed
- Food consumption and compound intake (if feeding study):
- no effects observed
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Histopathological findings: non-neoplastic:
- no effects observed
- Other effects:
- not examined
- Reproductive function: oestrous cycle:
- not examined
- Reproductive function: sperm measures:
- not examined
- Reproductive performance:
- not examined
- Dose descriptor:
- NOEC
- Effect level:
- > 40 000 ppm (analytical)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- other: see 'Remark'
- Remarks on result:
- other: Generation: results from 90 day inh. tox. study (migrated information)
- Clinical signs:
- not examined
- Mortality / viability:
- not examined
- Body weight and weight changes:
- not examined
- Sexual maturation:
- not examined
- Organ weight findings including organ / body weight ratios:
- not examined
- Gross pathological findings:
- not examined
- Histopathological findings:
- not examined
- Reproductive effects observed:
- not specified
- Conclusions:
- Body wts., body wt. gains, organ wts., clinical laboratory and biochemical measurements were analyzed by a one-way analysis of varience. Additionally, the F-test, Dunnet's test, Bonferroni correction, Cochran-Armitage test, Bartlett's test Kruskal-Wallis test and Mann-Whitney U test were applied as appropriate. The NOEL for this study was 40000 ppm (137600 mg/m3).
- Executive summary:
Body wts., body wt. gains, organ wts., clinical laboratory and biochemical measurements were analyzed by a one-way analysis of varience. Additionally, the F-test, Dunnet's test, Bonferroni correction, Cochran-Armitage test, Bartlett's test Kruskal-Wallis test and Mann-Whitney U test were applied as appropriate. The NOEL for this study was 40000 ppm (137600 mg/m3).
Referenceopen allclose all
In-life clinical observations were generally unremarkable. However, there was an unexpected mortality of lactating dams in the medium and high exposure level groups beginning with day 10 of lactation. In the F0 dams, the mortality pattern was 0/22 (control), 0/21 (low level), 2/21 (medium level), and 12/25 (high level). In addition, 4 of the dams in the high level were noted in poor condition. These animals generally appeared normal at the end of the day and were found dead the following morning. There was no treatment related mortality in the males or non-pregnant females. While there were a few incidents of decreases in body weight gain in the high level group, these tended to be at the beginning of the exposure phase of the study. No effect on mating or pregnancy rates were seen in the F0 generation. There were no gross pathological findings or effects on organ weights in the F0 rats, however there was a decrease in sperm motility in the high level males with a suggestion of a similar effect in the medium level. A significant increase in histopathological changes were seen in the cerebellum of 9/27 female rats in the high level group. A similar finding occurred in 1/30 female rats in the medium dose. Also 5/28 female rats in the high level group showed lesions in the cerebrum. No brain lesions were seen in male or non-pregnant female animals. Myocarditis was seen in both male and female rats: 3/30 (male, air control), 3/30 (male, medium level) and 15/30 (male, high level) as well as 1/30 (female, air control), 0/30 (female, medium level) and 6/30 (female, high level). Thus the findings in the medium level were similar to the air control, while the increase in the high level could be related to the exposure to HFC-245fa. Moderate to severe congestion was reported in the liver (10/30) and kidneys (11/30) in the high level exposure female rats. As the liver and kidney findings occurred only in animals that had died during the study and were present in all animals that died except for one dying on the last day, they appear to be agonal in nature and unrelated to the test compound exposure. All other lesions were judged to be incidental.
In the F1 pups, clinical observations were generally unremarkable. Sexual maturation was comparable across all groups. Body weight, body weight gains and food consumption, while showing some variations, tended to be unremarkable. Evaluations of locomotor activity, learning and memory were unaffected. As with the F0 generation, there was no effect on mating and pregnancy rates in the F1 generation. A similar pattern of mortality was seen in the F1 dams beginning on the 12 day of lactation, 0/18 (controls), 0/23 (low level), 2/23 (medium level) and 6/13 (high level) exposure groups. As noted above, these animals appeared normal at the end f the day and were found dead the following morning. In both male and female pups in the high level group and the female pups of the medium level group, there were depressions in many organ weights. These were judged to be a consequence of the lower terminal body weights. Histopathological examination of these pups did not show abnormalities in the lungs. Findings in the heart and kidney were equally divided in the control and high level groups. There were no other reported findings.
Gross pathological examination of the adult F1 rats did not reveal any treatment related findings. There were no treatment related findings on examination of sperm. Organ weights were comparable across all groups. Clinical chemical measurements of LDH, CK, and AST were unremarkable. The CK determinations were used to look for myocardial muscle damage. There was no evidence of myocardial damage. Blood samples were also analyzed for the presence of metabolites (trifluoroacetic acid and trifluoropropanoic acid). Only minimal levels of trifluoroacetic acid were found. Trifluoropropanoic acid levels were below the limits of detection. A significant increase in histopathological changes were seen in the cerebellum of 10/27 female rats in the high level group. A similar finding occurred in 1/30 female rats in the medium dose. Also 1/27 female rats in the high level group showed lesions in the cerebrum. No brain lesions were seen in male or non-pregnant female animals. Myocardial fibrosis was seen only in the female rats: 3/30 (female, air control), 0/30 (female, medium level) and 9/27 (female, high level). This increase in the high level could be related to the exposure to HFC-245fa. All other lesions were judged to be incidental.
In the F2 litters, there was a statistically significant increase in the number of still borne pups in the low and high level groups, but not the medium level. When the incidence of stillborn pups is combined with the incidence of pups not surviving until day 4, the incidence in the control, low and medium level groups is comparable. Thus it would appear that the increase in still borne pups and pups not surviving until day 4 was only associated with the high exposure level group. While there was a decrease in average litter size in the medium and high level groups, this was associated with the loss of complete litters as a consequence of maternal mortality (when the dams died, the pups in that litter was sacrificed) and not a direct effect of the exposure to the test article. Clinical observations and gross pathological observations did not show evidence for a treatment related effect. In the high level group, the right (but not left) testes was increased in weight in the males and the uterus and heart weight was increased in females. All other organ weights were normal. No abnormalities were detected in the cerebrum, cerebellum or heart by histopathological examination. In the liver, extramedullary haematopoesis was seen in all groups, including the controls. This was considered normal. While seen in the controls, in the high level group there was an increase in dilated tubules and interstitial fibrosis in the kidneys of the females.
In-life clinical observations were generally unremarkable. However, there was an unexpected mortality of lactating dams in the medium and high exposure level groups beginning with day 10 of lactation. In the F0 dams, the mortality pattern was 0/22 (control), 0/21 (low level), 2/21 (medium level), and 12/25 (high level). In addition, 4 of the dams in the high level were noted in poor condition. These animals generally appeared normal at the end of the day and were found dead the following morning. There was no treatment related mortality in the males or non-pregnant females. While there were a few incidents of decreases in body weight gain in the high level group, these tended to be at the beginning of the exposure phase of the study. No effect on mating or pregnancy rates were seen in the F0 generation. There were no gross pathological findings or effects on organ weights in the F0 rats, however there was a decrease in sperm motility in the high level males with a suggestion of a similar effect in the medium level. A significant increase in histopathological changes were seen in the cerebellum of 9/27 female rats in the high level group. A similar finding occurred in 1/30 female rats in the medium dose. Also 5/28 female rats in the high level group showed lesions in the cerebrum. No brain lesions were seen in male or non-pregnant female animals. Myocarditis was seen in both male and female rats: 3/30 (male, air control), 3/30 (male, medium level) and 15/30 (male, high level) as well as 1/30 (female, air control), 0/30 (female, medium level) and 6/30 (female, high level). Thus the findings in the medium level were similar to the air control, while the increase in the high level could be related to the exposure to HFC-245fa. Moderate to severe congestion was reported in the liver (10/30) and kidneys (11/30) in the high level exposure female rats. As the liver and kidney findings occurred only in animals that had died during the study and were present in all animals that died except for one dying on the last day, they appear to be agonal in nature and unrelated to the test compound exposure. All other lesions were judged to be incidental.
In the F1 pups, clinical observations were generally unremarkable. Sexual maturation was comparable across all groups. Body weight, body weight gains and food consumption, while showing some variations, tended to be unremarkable. Evaluations of locomotor activity, learning and memory were unaffected. As with the F0 generation, there was no effect on mating and pregnancy rates in the F1 generation. A similar pattern of mortality was seen in the F1 dams beginning on the 12 day of lactation, 0/18 (controls), 0/23 (low level), 2/23 (medium level) and 6/13 (high level) exposure groups. As noted above, these animals appeared normal at the end f the day and were found dead the following morning. In both male and female pups in the high level group and the female pups of the medium level group, there were depressions in many organ weights. These were judged to be a consequence of the lower terminal body weights. Histopathological examination of these pups did not show abnormalities in the lungs. Findings in the heart and kidney were equally divided in the control and high level groups. There were no other reported findings.
Gross pathological examination of the adult F1 rats did not reveal any treatment related findings. There were no treatment related findings on examination of sperm. Organ weights were comparable across all groups. Clinical chemical measurements of LDH, CK, and AST were unremarkable. The CK determinations were used to look for myocardial muscle damage. There was no evidence of myocardial damage. Blood samples were also analyzed for the presence of metabolites (trifluoroacetic acid and trifluoropropanoic acid). Only minimal levels of trifluoroacetic acid were found. Trifluoropropanoic acid levels were below the limits of detection. A significant increase in histopathological changes were seen in the cerebellum of 10/27 female rats in the high level group. A similar finding occurred in 1/30 female rats in the medium dose. Also 1/27 female rats in the high level group showed lesions in the cerebrum. No brain lesions were seen in male or non-pregnant female animals. Myocardial fibrosis was seen only in the female rats: 3/30 (female, air control), 0/30 (female, medium level) and 9/27 (female, high level). This increase in the high level could be related to the exposure to HFC-245fa. All other lesions were judged to be incidental.
In the F2 litters, there was a statistically significant increase in the number of still borne pups in the low and high level groups, but not the medium level. When the incidence of stillborn pups is combined with the incidence of pups not surviving until day 4, the incidence in the control, low and medium level groups is comparable. Thus it would appear that the increase in still borne pups and pups not surviving until day 4 was only associated with the high exposure level group. While there was a decrease in average litter size in the medium and high level groups, this was associated with the loss of complete litters as a consequence of maternal mortality (when the dams died, the pups in that litter was sacrificed) and not a direct effect of the exposure to the test article. Clinical observations and gross pathological observations did not show evidence for a treatment related effect. In the high level group, the right (but not left) testes was increased in weight in the males and the uterus and heart weight was increased in females. All other organ weights were normal. No abnormalities were detected in the cerebrum, cerebellum or heart by histopathological examination. In the liver, extramedullary haematopoesis was seen in all groups, including the controls. This was considered normal. While seen in the controls, in the high level group there was an increase in dilated tubules and interstitial fibrosis in the kidneys of the females.
Exposure concentrations were close to target values (Table 1)
Pharmacokinetics
HFA 134a was absorbed into the systemic circulation. Concentrations increased with increasing dose. Elimination was rapid and there was no apparent accumulation on repeat dosing (Table 2). The mean half-life of HFA 134a was 5.8 and 7 minutes for the study.
Clinical observation
Mortality: no mortality was related to treatment.
One F0 male dosed at 50 000 ppm was killed for human reasons in Week 5 due to noisy respiration and red staining around the nose and eyes. There were no findings at autopsy to account for its condition.
Clinical signs: there were no clinical effects of treatment observed.
Food consumption: There was no effect of treatment on food consumption.
Body weights
There was a slight but statistically significant reduction in body weight gain of F0 males dosed at 10 000 and 50 000 ppm after 2 weeks of exposure. Cumulative (Weeks 0 – 5) and overall (Weeks 0 – 10) weight gains of males were reduced also at 50 000 ppm. However, there were no effects on weight gain in F0 females.
Amongst F1 rats, there were no significant effects upon the mean body weights of pups, nor on the growth rate of litters, when compared with the control group. This continued to be the case with all retained F1 animals during pre-mating and pregnancy. Towards the end of lactation, F2 litters in the 50 000 ppm group showed a slight decrease in weight to those from control animals which was slight and considered not to be attributable to treatment of the F0 generation. Weight gains of the F2 animals were comparable between the groups.
Breeding performance
There was no evidence of any effect on oestrous cycles, mating, pre-coital times, conception or on the length of gestation in the F0 and F1 generations (Tables 3 and 5).
Post mortem observations
No abnormalities attributable to HFA 134a were detected in F0 and F1 males, in F0 and F1 Females at termination of pregnancy or at the end of lactation
Findings in F0 females.
The number of corpora lutea. Implants, embryonic deaths, live you, sex ratio, litter weights and F1 foetal body weights did not differ significantly between treated and control groups.
Litter data of F0 dams rearing young. The numbers of live born pups, their sex ratio and their survival post partum were unaffected by treatment (Table 4). There were two litter losses, one due to total embryonic death (2500 ppm), the other to unsuccessful weaning (10 000 ppm). Neither were attributed to treatment.
Post natal development of the F1 generation. There was no evidence of a treatment related effect on the mean day of eruption of upper incisors nor in the appearance of surface, air righting and pupillary reflexes (Table 6). Vaginal opening and cleavage of the balanopreputial skinfold were likewise unaffected, and differences between animals in the treated groups and controls in the rotarod, activity and learning tests were considered to be on no importance. There were no treatment related ocular effects in F1 animals. There were no effect of treatment on the mean day on which pinnae detachment, eye opening and the startle response occurred (Table 6).
Litter data of F1 dams rearing young. The numbers of live born pups, their sex and their survival post partum were unaffected by treatment (Table 5). Physical and functional development of the F2 generation was considered to be unaltered as, despite the occasional statistically significant difference in certain developmental markers (pinna detachment, startle response, and air righting reflex), non of the group means exceeded one day’s difference from control values and there was no dose relationship (Table 7).
No abnormalities attributable to HFA 134a were detected in the sexually mature F2 animals. In addition, macroscopic examination of F1 and F2 generation rats at weaning did not reveal any abnormalities of significance.
There were no effects of treatment upon the incidence, type and distribution of visceral or skeletal abnormalities in foetuses from the F0 generation females killed on Day 20 post coitum (Table 8).
Table 1. Treatment of the dose groups
Group |
Target Conc. (ppm) |
Fertility Study Measured mean ppm (SD) |
1.Control |
0 |
|
2.Low |
2500 |
2595 (170) |
3.Intermediate |
10000 |
10080 (452) |
4.High |
50000 |
49308 (3281) |
Table 2. Mean (standard deviation) blood HFA 134a concentration (Cmax ug/ml)
Group |
During exposure |
After exposure |
2.Low |
2.9 (0.5) |
<1 |
3.Intermediate |
11.3 (3.6) |
2.7 (1.2) |
4.High |
68.2 (14.6) |
5.2 (2.1) |
Table 3. Breeding performance of F0 females.
Group 1 |
Group 2 |
Group 3 |
Group 4 |
|
Females paired |
30 |
30 |
30 |
30 |
Females mated |
30 |
30 |
30 |
30 |
Females pregnant |
30 |
30* |
30** |
30 |
Median precoital time (days)*** |
3.0 |
2.0 |
2.0 |
3.0 |
Females examined |
14 |
14 |
14 |
14 |
Corpora lutea |
15.6 |
16.6 |
15.8 |
16.2 |
Implantations |
14.2 |
15.5 |
15.4 |
14.4 |
Intra uterine deaths |
1.0 |
0.6 |
1.1 |
1.4 |
Live young/litter |
13.2 |
14.9 |
14.3 |
13.1 |
Litter weight (g) |
45.22 |
50.30 |
47.91 |
44.18 |
Foetal weight (g) |
3.44 |
3.38 |
3.36 |
3.37 |
* one dam with total embryonic death; ** one dam with total litter loss post partum; *** day by which half the number of pair females had mated.
Table 4. Group mean findings from F0 females allowed to litter and rear their offspring
Group 1 |
Group 2 |
Group 3 |
Group 4 |
|
Females examined |
16 |
16 |
16 |
16 |
Females pregnant |
16 |
15* |
16** |
16 |
Gestation length (days) |
21.8 |
21.9 |
22.0 |
21.8 |
Implantation sites |
14.9 |
14.3 |
14.6*** |
14.8 |
Number in litter |
13.8 |
13.4 |
14.0 |
13.3 |
% males/litter at birth |
56.2 |
54.1 |
51.4 |
51.1 |
% males/litter on Day 21 post partum |
55.7 |
54.5 |
51.6 |
52.1 |
Live young/litter at birth |
13.8 |
13.4 |
13.7 |
13.1 |
Live young/litter Day 21 post partum |
13.6 |
13.1 |
13.5 |
12.8 |
Litter weight at birth (g) |
77.8 |
78.3 |
79.3 |
74.8 |
Litter weight Day 21 post partum (g) |
537.9 |
527.9 |
526.3 |
496.1 |
Pup body weight at birth (g) |
5.7 |
5.9 |
5.8 |
5.8 |
Pup body weight Day 21 post part (g) |
40.0 |
41.0 |
40.2 |
40.2 |
* one dam with total embryonic death; ** one dam with total litter loss post partum; *** excludes one litter where implantation sites were not recorded.
Table 5. Breeding performance of F1 generation
Group 1 |
Group 2 |
Group 3 |
Group 4 |
|
Females paired |
12 |
12 |
12 |
12 |
Females mated |
12 |
12 |
12 |
12 |
Females pregnant |
12 |
11 |
12* |
12 |
Median pre-coital time (days) |
3.0 |
3.0 |
2.0 |
3.0 |
Mean gestation length (days) |
21.6 |
21.8 |
22.1 |
21.6 |
Females weaning young |
12 |
11 |
11 |
12 |
Implantation sites |
15.8 |
15.0 |
15.9 |
15.8 |
Number in litter |
14.5 |
14.4 |
15.5 |
15.4 |
% Males/litter at birth |
48.6 |
44.6 |
51.9 |
53.4 |
% Males/litter Day 21 post partum |
48.4 |
44.4 |
51.2 |
53.5 |
Live young/litter at birth |
14.5 |
14.4 |
15.0 |
15.3 |
Live young/litter Day 21 post partum |
14.3 |
14.4 |
14.9 |
15.3 |
Litter weight (g) at birth |
86.2 |
87.3 |
90.5 |
91.1 |
Litter weight (g) Day 21 post partum |
580.2 |
580.1 |
581.9 |
558.8 |
Pup body weight (g) at birth |
5.9 |
6.1 |
6.1 |
6.0 |
Pup body weight (g) Day 21 post part |
40.7 |
40.7 |
40.4 |
37.1** |
* one dam with total litter loss post partum; **statistically significant decrease from control (P<0.05)
Table 6. Development of the F1 generation
Mean age (day post-coitum) of appearance |
||||
Group 1 |
Group 2 |
Group 3 |
Group 4 |
|
Number of animals |
12 |
12 |
12 |
12 |
Pinna detachment |
24.9 |
25.1 |
24.9 |
24.8 |
Upper incisor eruption |
30.3 |
30.0 |
30.0 |
30.1 |
Eye opening |
37.0 |
37.0 |
37.1 |
36.8 |
Reflex development: |
||||
Surface righting |
24.2 |
24.6 |
24.7 |
24.6 |
Startle response |
34.7 |
34.6 |
34.3 |
34.3 |
Air righting |
37.8 |
37.5 |
37.5 |
37.5 |
Pupil reflex (% success on Day 20 post partum) |
100 |
100 |
100 |
100 |
Cleavage of balanopreputial skinfold |
43.9 |
44.7 |
43.5 |
44.5 |
Vaginal opening |
32.3 |
33.4 |
33.3 |
33.6 |
Table 7. Development of the F2 generation
Mean age (day post-coitum) of appearance |
||||
Group 1 |
Group 2 |
Group 3 |
Group 4 |
|
Number of animals |
8 |
8 |
8 |
8 |
Pinna detachment |
23.7 |
23.8 |
24.4** |
23.7 |
Upper incisor eruption |
30.2 |
30.4 |
30.7 |
30.3 |
Eye opening |
36.6 |
36.7 |
37.0 |
36.7 |
Reflex development: |
||||
Surface righting |
23.5 |
23.5 |
24.0 |
23.4 |
Startle response |
33.8 |
33.9 |
34.3** |
34.3* |
Air righting |
36.6 |
37.2* |
37.6* |
37.1 |
Pupil reflex (% success on Day 20 post partum) |
100 |
99 |
100 |
100 |
Cleavage of balanopreputial skinfold |
44.6 |
45.0 |
43.8 |
45.4 |
Vaginal opening |
31.6 |
32.5 |
32.6 |
32.4 |
* statistically significant increases from control group (P<0.05); **(P<0.01)
Table 8 Abnormalities in foetuses from F0 generation killed on Day 20 post coitum.
Group 1 |
Group 2 |
Group 3 |
Group 4 |
|
Major abnormalities |
||||
Foetuses examined |
185 |
209 |
200 |
183 |
Foetuses with major defects |
1 |
2 |
0 |
0 |
Anury |
1 |
|||
Retroesophageal aortic arch |
1 |
|||
Cranial meningocoele |
1 |
|||
Minor abnormalities* |
||||
Foetuses examined for visceral defects |
91 |
102 |
103 |
93 |
Foetuses with visceral defects |
12 |
9 |
15 |
9 |
Absent innominate artery |
2 |
1 |
||
Variation in origin of arteries from aortic arch |
1 |
|||
Abnormal lobulation of the liver |
1 |
3 |
2 |
6 |
Dilatation of renal pelvis +/- ureter |
10 |
3 |
6 |
3 |
Displacement of one testis |
2 |
4 |
||
Reduction in size of thyroid |
1 |
|||
Small intraventricular septal defect |
1 |
|||
Minimal dilatation of orbital sinus |
1 |
|||
Foetuses examined for skeletal defects |
93 |
105 |
97 |
90 |
Foetuses with skeletal defects |
7 |
9 |
13 |
11 |
One/two bipartite thoracic centra |
2 |
3 |
7 |
4 |
One/two butterfly-shaped thoracic centra |
4 |
3 |
2 |
3 |
Butterfly-shaped lumbar centrum |
1 |
|||
Shortened rib |
1 |
|||
Right cervical rib |
1 |
|||
Extra thoraco-lumbar vertebrae |
2 |
|||
Asymmetrical alignment of costal cartilage elements |
1 |
1 |
||
Reduced ossification of cranium |
1 |
|||
Reduced ossific’n of vertebral arches |
1 |
1 |
||
Reduced ossification of rib |
1 |
|||
Unossified 5thmetatarsals |
1 |
3 |
1 |
BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS) no effects observed
TEST SUBSTANCE INTAKE (PARENTAL ANIMALS) inhalation study, dose not measured
REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS) not determined
REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS) not measured
REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS) not determined
ORGAN WEIGHTS (PARENTAL ANIMALS) no effects seen even at the highest exposure level of 40000 ppm
GROSS PATHOLOGY (PARENTAL ANIMALS) no significant findings
HISTOPATHOLOGY (PARENTAL ANIMALS) no significant findings
OTHER FINDINGS (PARENTAL ANIMALS) no significant findings
Effect on fertility: via oral route
- Endpoint conclusion:
- no study available
Effect on fertility: via inhalation route
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- NOAEC
- 2 000 ppm
- Study duration:
- subchronic
- Experimental exposure time per week (hours/week):
- 28
- Species:
- rat
- Quality of whole database:
- Sufficient to address requirements.
Effect on fertility: via dermal route
- Endpoint conclusion:
- no study available
Effects on developmental toxicity
Description of key information
The substance showed no maternal toxicity nor developmental effects in rat and rabbit developmental toxicity studies.
Link to relevant study records
- Endpoint:
- developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: GLP OECD Guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 414 (Prenatal Developmental Toxicity Study)
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Limit test:
- no
- Species:
- rat
- Strain:
- Sprague-Dawley
- Details on test animals or test system and environmental conditions:
- 162 nulliparous females, 64 days old were received from Charles River Breeding Lab., Kingston, NY. Males of the same strain were used for breeding. Rats were individually housed in wire mesh cages in temperature (21-25 deg.C) and humidity (40-60%) controlled rooms with a 12 hr light-dark cycle. They were given Purina Rodent Chow #5002 and tap water ad libitum except during exposures.
- Route of administration:
- inhalation: gas
- Type of inhalation exposure (if applicable):
- whole body
- Vehicle:
- unchanged (no vehicle)
- Details on exposure:
- exposures were conducted daily on days 7-16 of gestation for 6 hrs/day.
- Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- Samples of the chamber air were withdrawn hourly and analyzed by gas chromatography. Nominal concentrations were within 90 to 110% of analytical controls.
- Details on mating procedure:
- Females were individually caged with males from an in-house colony. Copulation was determined (Day 1) by the presence of a copulation plug.
- Duration of treatment / exposure:
- Exposures were conducted daily from Day 7 through day 16 of gestation.
- Frequency of treatment:
- daily
- Duration of test:
- From day of copulation plug until day 21.
- Remarks:
- Doses / Concentrations:
0 (control), 2000, 10000, and 40000 ppm
Basis:
analytical conc. - No. of animals per sex per dose:
- 25
- Control animals:
- yes, sham-exposed
- Maternal examinations:
- Animals were observed on arrival, twice during quarantine, daily in the morning from Day 1- 22 and in the afternoon on days 7-16. Body weights were measured on days 1, 7, 9, 11, 13, 15, 17 and 22G. Food consumption was measured on the same days as well as on days 3 and 5.
- Ovaries and uterine content:
- The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes - Fetal examinations:
- - External examinations: Yes: [all per litter ]
- Soft tissue examinations: Yes: [ half per litter ]
- Skeletal examinations: Yes: [ half per litter ]
- Head examinations: Yes: [ #? per litter ] - Statistics:
- Statistical evaluations will be at p
- Indices:
- At termination viscera will be examined grossly, uterine weight measured, corpora lutea counted for each ovary with the number of viable fetuses recorded. The number of implantations will be determined using ammonium sulfate staining and the number of early resorptions calculated. Fetuses will be examined for soft tissue abnormalities or skeletal abnormalities
- Historical control data:
- Historical control data are available if needed to clarify uncertainties.
- Details on maternal toxic effects:
- Maternal toxic effects:no effects
Details on maternal toxic effects:
HFC-143a was administered by inhalation to groups of 25 female rats on days 7 -16 of gestation at exposure levels of 0, 2000, 10000, and 40000 ppm. There was no evidence of maternal or developmental toxicity at any level tested. The NOEC was greater than 40,000 ppm for the dam and conceptus. - Key result
- Dose descriptor:
- NOEC
- Effect level:
- > 40 000 ppm (analytical)
- Based on:
- test mat.
- Basis for effect level:
- other: other:
- Details on embryotoxic / teratogenic effects:
- Embryotoxic / teratogenic effects:no effects
Details on embryotoxic / teratogenic effects:
HFC-143a was administered by inhalation to groups of 25 female rats on days 7 -16 of gestation at exposure levels of 0, 2000, 10000, and 40000 ppm. There was no evidence of maternal or developmental toxicity at any level tested. The NOEC was greater than 40,000 ppm for the dam and conceptus. - Key result
- Dose descriptor:
- NOEC
- Effect level:
- > 40 000 ppm
- Based on:
- test mat.
- Sex:
- not specified
- Remarks on result:
- not determinable due to absence of adverse toxic effects
- Abnormalities:
- not specified
- Key result
- Developmental effects observed:
- no
- Lowest effective dose / conc.:
- 40 000 ppm
- Conclusions:
- HFC-143a was administered by inhalation to groups of 25 female rats on days 7 -16 of gestation at exposure levels of 0, 2000, 10000, and 40000 ppm. There was no evidence of maternal or developmental toxicity at any level tested. The NOEC was greater than 40,000 ppm for the dam and conceptus.
- Executive summary:
HFC-143a was administered by inhalation to groups of 25 female rats on days 7 -16 of gestation at exposure levels of 0, 2000, 10000, and 40000 ppm. There was no evidence of maternal or developmental toxicity at any level tested. The NOEC was greater than 40,000 ppm for the dam and conceptus.
- Endpoint:
- developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1993
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: GLP OECD Guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 414 (Prenatal Developmental Toxicity Study)
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Limit test:
- no
- Species:
- rabbit
- Strain:
- New Zealand White
- Details on test animals or test system and environmental conditions:
- 110 sexually mature, virgin female rabbits were received from Hazleton Research Products, Inc, Denver CO. Animals were housed from 5 to 8 weeks prior to study initiation. Rabbits were individually housed in wire mesh cages in temperature (17-22 deg.C) and humidity (30-70%) controlled rooms with a 12 hr light-dark cycle. They were given Purina Rabbit Chow #5322 and tap water ade libitum except during exposures. Pregnancy was induced by artificial insemination using pooled seman from 8 resident males.
- Route of administration:
- inhalation: gas
- Type of inhalation exposure (if applicable):
- whole body
- Vehicle:
- unchanged (no vehicle)
- Details on exposure:
- exposures were conducted daily on days 6-18 of gestation for 6 hrs/day using 1.5 cubic meter chambers
- Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- Samples of the chamber air were withdrawn at least 3 times during each exposure and analyzed by gas chromatography. Nominal concentrations were within 90 to 110% of analytical controls.
- Details on mating procedure:
- Females were artificially inseminated using pooled seman collected from 8 males from an in-house colony.
- Duration of treatment / exposure:
- Exposures were conducted daily from Day 6 through day 18 of gestation. Each exposure was for 6 hours.
- Frequency of treatment:
- daily
- Duration of test:
- From day of copulation plug until day 29.
- Remarks:
- Doses / Concentrations:
0 (control), 2000, 10000, and 40000 ppm
Basis:
analytical conc. - No. of animals per sex per dose:
- 24
- Control animals:
- yes, sham-exposed
- Maternal examinations:
- Animals were observed on arrival, daily during holding, and daily prior to exposure from Day 1- 29. Body weights were measured on days 0, 6-19, daily, and on days 24 and 29. Food consumption was measured daily.
- Ovaries and uterine content:
- The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes - Fetal examinations:
- - External examinations: Yes: [all per litter ]
- Soft tissue examinations: Yes: [ half per litter ]
- Skeletal examinations: Yes: [ half per litter ]
- Head examinations: Yes: [ #? per litter ] - Statistics:
- Statistical evaluations were at p
- Indices:
- At termination viscera will be examined grossly, uterine weight measured, corpora lutea counted for each ovary with the number of viable fetuses recorded. The number of implantations will be determined using ammonium sulfate staining and the number of early resorptions calculated. Fetuses will be examined for soft tissue abnormalities or skeletal abnormalities
- Historical control data:
- Historical control data are available if needed to clarify uncertainties.
- Details on maternal toxic effects:
- Maternal toxic effects:no effects
- Key result
- Dose descriptor:
- NOEC
- Effect level:
- > 40 000 ppm (analytical)
- Basis for effect level:
- other: other:
- Details on embryotoxic / teratogenic effects:
- Embryotoxic / teratogenic effects:no effects
- Key result
- Dose descriptor:
- NOAEC
- Effect level:
- > 40 000 ppm
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- external malformations
- skeletal malformations
- Remarks on result:
- not determinable due to absence of adverse toxic effects
- Key result
- Abnormalities:
- no effects observed
- Key result
- Developmental effects observed:
- not specified
- Conclusions:
- HFC-143a was administered by inhalation to groups of 24 female rabbits on days 6 -18 of gestation at exposure levels of 0, 2000, 10000, and 40000 ppm. There was no evidence of maternal or developmental toxicity at any level tested. The NOEC was greater than 40,000 ppm for the dam and conceptus.
- Executive summary:
HFC-143a was administered by inhalation to groups of 24 female rabbits on days 6 -18 of gestation at exposure levels of 0, 2000, 10000, and 40000 ppm. There was no evidence of maternal or developmental toxicity at any level tested. The NOEC was greater than 40,000 ppm for the dam and conceptus.
Referenceopen allclose all
HFC-143a was administered by inhalation to groups of 25 female rats on days 7 -16 of gestation at exposure levels of 0, 2000, 10000, and 40000 ppm. There was no evidence of maternal or developmental toxicity at any level tested. Treatment-related findings were not observed in litter size, embryo-fetal loss and litter and fetal weight. Effects on the incidence of malformation were not observed at any exposure level. A significant increase in the incidence of fetal visceral variations in the litters of all the exposed groups in comparison to the control group was seen. The actual incidences were 1.6, 10.5, 8.7, and 10.0 % for the 0, 2000, 10000, and 40000 ppm groups, respectively. Retarded renal papillary development was the primary and most frequently recorded observation. The higher values observed in the 1,1,1-trifluoroethane-exposed litters are not considered to be biologically significant for three reasons. First, in the study, the control value was abnormally low relative to historical control values for retarded renal papillary development which averaged 10.5% and ranged from 6.8 to 16.2 % for 5 other studies conducted within the same period (1991-1992). Second, the increases did not show concentration-dependent response. Third, there was a lack of other developmental effects in the study. The NOAEC for maternal and developmental toxicity in rats was 40,000 ppm
HFC-143a was administered by inhalation to groups of 24 female rabbits on days 6 -18 of gestation at exposure levels of 0, 2000, 10000, and 40000 ppm. There was no evidence of maternal or developmental toxicity at any level tested. The NOEC was greater than 40,000 ppm for the dam and conceptus.
Effect on developmental toxicity: via oral route
- Endpoint conclusion:
- no study available
Effect on developmental toxicity: via inhalation route
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- NOAEC
- 137 600 mg/m³
- Study duration:
- subacute
- Species:
- rat
Effect on developmental toxicity: via dermal route
- Endpoint conclusion:
- no study available
Additional information
Developmental toxicity studies were conducted in Sprague Dawley rats (gestation days 7-16) and New Zealand rabbits (gestation days 6-18) using daily 6-hr exposures at up to 137600mg/m3 (40000 ppm). There were no effects on either the adults or the offspring. The level of 137600 mg/m3 was chosen as it is 50% of the lower flammability level.
Justification for classification or non-classification
In a reliable two generation inhalation study conducted on a structural analogue, adverse effects on fertility and reproductive performance were observed but only at doses that caused maternal lethality and therefore these effects are not relevant for classification purposes. Some effects were seen in the absence of marked systemic toxicity however these were not statistically significant and/or showed an incomplete pattern of dose dependence. In addition, two reliable developmental toxicity studies conducted on the substance itself in the rat and rabbit respectively showed no evidence of developmental effects. Overall there is insufficient evidence to justify classification of the substance for reproductive toxicity.
Additional information
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
