Registration Dossier

Toxicological information

Endpoint summary

Currently viewing:

Administrative data

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records
Reference
Endpoint:
toxicity to reproduction
Remarks:
other: dominant lethal assay
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
This study is used for read-across and therefore has been assigned a reliability of 2 (reliable with restrictions). Otherwise the study has a reliability of 1 (reliable without restriction). This study was selected as the key study because the information provided for the hazard endpoint is sufficient for the purpose of classification and labeling and/or risk assessment.
Qualifier:
according to
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
Details on test animals and environmental conditions:
CD-1 male mice, seven to eight weeks old, were supplied by Charles River UK Ltd, Margate, Kent and housed individually on double-sided mobile mouse racks, each having stainless steel cages of internal measurements: length 28.5 cm, width 11 cm and height 7.5 cm and wire mesh floors. The mice were sequentially numbered by ear punching and were housed in this same order.

Female CD1 mice, eight to nine weeks old, were supplied with the males while further batches of females were supplied at weekly intervals during the experiment. Before mating they were acclimatised to their new environment for 12 days and were housed 10 per cage on rack similar to that described for males with cages of internal measurements: length 27.5 cm, width 25.5 cm, height 10 cm. After mating they were housed 2 per cage and identified with the number of the male with which they were housed during mating.

The environment was maintained at 21 – 25°C with relative humidity at approximately 50%. Alternate 12 hr light and dark cycles were controlled with a timer starting at 6 am. The animals received Alderley Park diet supplied and water (provided by an automatic drinker system) ad libitum except for the males during the exposure period.
Route of administration:
inhalation
Type of inhalation exposure (if applicable):
whole body
Vehicle:
unchanged (no vehicle)
Details on exposure:
The HFC 134a treated animals were exposed by inhalation each day for six hours per day on five consecutive days. The negative and positive controls were similarly housed in exposure chambers receiving air. During exposure animals were housed individually without access to food or water in one of twenty compartments in a box made of steel and glass with an internal capacity of approximated 3 litres. Atmospheres of HFC 134a were generated by mixing volumes of the test compounds with air and using rotameters as initial indicators of concentration. The concentrations were monitored by a gas-liquid chromatograph (GLC). The animals of the two positive control groups were maintained in a similar air flow to the negative control animals but were dosed prior to being housed in the exposure boxes. They received either five daily oral doses of ethyl methanesulphonate (EMS) in distilled water or a single intraperitoneal injection of cyclophosphamide in 0.9% saline.
Details on mating procedure:
During exposure animals were housed individually without access to food or water in one of twenty compartments in a box made of steel and glass with an internal capacity of approximated 3 litres. Test substance atmospheres were generated by mixing volumes of the test compound with air and using rotameters as initial indicators of concentration. The concentrations were monitored by a gas-liquid chromatograph (GLC). The animals of the two positive control groups were maintained in a similar air flow to the negative control animals but were dosed prior to being housed in the exposure boxes. They received either five daily oral doses of ethyl methanesulphonate (EMS) in distilled water or a single intraperitoneal injection of cyclophosphamide in 0.9% saline.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Atmospheric concentrations in the exposure chambers were monitored by gas-liquid chromatography and mean atmospheric concentrations calculated
Duration of treatment / exposure:
5 days
Frequency of treatment:
6 hours/day
Remarks:
Doses / Concentrations:
0, 1000, 10000, 50000 ppm
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
0, 900, 10200, 50700 ppm
Basis:
analytical conc.
No. of animals per sex per dose:
30 males for mating from negative control
15 males for mating from test substance and positive controls
Control animals:
yes, sham-exposed
Details on study design:
After an acclimatisation period of 12 days, a pre-experimental fertility test was carried out on the males. Two females were housed with each male, left for four nights, then re-housed. It was assumed that most matings would take place soon after pairing. The females were therefore not examined for vaginal plugs, but were killed (by cervical dislocation) 15 days after first introducing them to the males. Their uteri were examined for live implantations, early deaths and late deaths. The animals were graded according to fertility and extent of background dominant lethal frequency, choosing where possible those successful in fertilising both females but excluding those with a high dominant lethal frequency. The selected males were randomly allocated to six experimental groups. Following the allocation process the males remained housed sequentially on the racks so the groups to which they were allocated were therefore randomly distributed. The experimental outline and groups sizes are shown in Table 1, excess animals being included at this stage to allow for deaths or ill resulting from dosing.
Positive control:
5 oral doses of ethyl methane sulphonate (EMS) or a single i.p. dose of cyclophosphamide (CTX)
Parental animals: Observations and examinations:
All animals were checked daily throughout the study, the males being checked twice daily during exposure. All abnormal observations were recorded.
Postmortem examinations (parental animals):
Deaths were recorded, but the animals were not given a post-mortem examination.
Statistics:
Data from the test substance exposed groups and positive control groups were compared statistically with those from the negative control groups.
To assess fertility, two methods were used:
i) the percentage of pregnant females was analysed using the Chi-squared test
ii) the number of successful matings per male was analysed using Student’s t-test
Pre-implantation egg losses, whilst representing some of the mutagenic effect, are not as important as the post-implantational losses since such losses could be due to other than genetic factors. Pre-implantation egg loss in the present study has thus been measured by comparing values of total implantations in females mated with treated males and control males instead of counting corpora lutea. The total number of implantations per pregnancy was considered by analysis of variance and group means were compared using a one-sided Student’s t-test based on this analysis.
Reproductive indices:
The number of early deaths, late deaths and live implantations observed during the uterine examination were recorded and the resultant data processed and analysed statistically.
Clinical signs:
no effects observed
Body weight and weight changes:
not examined
Food consumption and compound intake (if feeding study):
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Other effects:
not examined
Reproductive function: oestrous cycle:
not examined
Reproductive function: sperm measures:
not examined
Reproductive performance:
no effects observed
Dose descriptor:
NOEC
Effect level:
50 000 ppm
Sex:
male
Basis for effect level:
other: No effects on reproductive performance of male mice at highest concentration tested.
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

Table 2: Daily atmospheric concentrations (%v/v) - standard deviations are in parenthesis

Day

Test substance

1000 ppm (0.1% v/v)

10 000 ppm (1.0% v/v)

50 000 ppm (5.0% v/v)

1

0.07 (0.03)

1.10 (0.23)

5.24 (0.60)

2

0.08 (0.01)

1.05 (0.25)

5.41 (0.51)

3

0.07 (0.06)

0.98 (0.12)

4.74 (0.21)

4

0.10 (0.01)

0.96 (0.08)

5.00 (0.14)

5

0.12 (0.09)

0.99 (0.12)

4.97 (0.73)

Mean

0.09 (0.02)

1.02 (0.06)

5.07 (0.26)

 

Fertility (Tables 3 and 4):

 

Percentage of Females pregnant (Table 3): The only significant effect in the test substance treated groups occurred in week 7 where there was a reduction in pregnancy in the low dose group. The positive control groups had significantly lower percentages in weeks 1, 2, 7, and 8 for EMS and weeks 1, 3, 4, 6, and 7 for CTX.

 

Table 3: Percentage of mated female mice that became pregnant

Test substance

EMS

CTX

Weeks

Control

1000 ppm

10 000 ppm

50 000 ppm

150 mg/kg orally

200 mg/kg i.p.

Before treatment

98.3 (60)

96.7 (30)

100 (30)

100 (30)

100 (30)

96.7 (30)

1

90.0 (60)

93.3 (30)

90.0 (30)

83.3 (30)

60.0 ** (30)

70.0* (30)

2

93.3 (60)

80.0 (30)

96.7 (30)

90.0 (30)

66.7* (30)

83.3 (30)

3

95.0 (60)

93.3 (30)

93.3 (30)

90.0 (30)

100 (30)

76.7* (30)

4

96.7 (60)

93.3 (30)

100 (30)

93.3 (30)

93.3 (30)

76.7* (30)

5

95.0 (60)

86.7 (30)

93.3 (30)

93.3 (30)

90.0 (30)

92.9 (28)

6

91.7 (60)

90.0 (30)

96.6 (29)

90.0 (30)

100 (30)

57.7*** (26)

7

100 (60)

83.3** (30)

96.7 (30)

93.3 (30)

90.0* (30)

70.0*** (20)

8

98.3 (60)

100 (26)

96.7 (30)

96.7 (30)

83.3* (30)

57.1*** (14)

The number in brackets is the total number of females mated in the experiment at a given time.

Statistically significant differences compared to control: *5%, **1%,***0.1% level based on the χtest.

 

Successful mating per male (Table 4): Both the low and high dose test substance groups had reduced mean numbers of successful matings per male in week 7. The value for the middle dose group was slightly lower than for control and the pooled group value was also significantly lower. The analysis of the two positive control groups gave the same significant values as those described for the percentages of females pregnant.

 

 

Table 4: Frequency distribution (and mean number†) of successful matings per male mouse

Test substance

EMS

CTX

Weeks

Number of successful matings

Control

1000 ppm

10 000 ppm

50 000 ppm

150 mg/kg orally

200 mg/kg i.p.

Before treatment

0

1

2

0

1

29 (100%)

0

1

14

(100%)

0

0

15

(100%)

0

0

15

(100%)

0

0

15

(100%)

0

1

14

(100%)

1

0

1

2

1

4

25

(96.7%)

0

2

13

(100%)

0

3

12

(100%)

0

5

10

(100%)

1***

10

4

(93.3%)

1*

7

7

(93.3%)

2

0

1

2

0

4

26

(100%)

2

2

11

(86.7%)

0

1

14

(100%)

0

3

12

(100%)

2**

6

7

(86.7%)

1

3

11

(93.3%)

3

0

1

2

0

3

27

(100%)

0

2

13

(100%)

0

2

13

(100%)

0

3

12

(100%)

0

0

15

(100%)

2*

3

10

(86.7%)

4

0

1

2

0

2

28

(100%)

1

0

14

(93.3%)

0

0

15

(100%)

0

2

13

(100%)

0

2

13

(100%)

2**

3

10

(86.7%)

5

0

1

2

0

3

27

(100%)

1

2

12

(93.3%)

0

2

13

(100%)

0

2

13

(100%)

0

3

12

(100%)

1

0

13

(92.9%)

6

0

1

2

0

5

25

(100%)

1

1

13

(93.3%)

0

1

13

(100%)

1

1

13

(93.3%)

0

0

15

(100%)

5**

1

7

(61.6%)

7

0

1

2

0

0

30

(100%)

1**

3

11

(93.3%)

0

1

14

(100%)

0*

2

13

(100%)

0**

3

12

(100%)

2***

2

6

(80.0%)

8

0

1

2

0

1

29

(100%)

0

0

13

(100%)

0

1

14

(100%)

0

1

14

(100%)

0**

5

10

(100%)

3***

0

4

57.1%

Statistically significant differences compared to control: *5%, **1%, ***0.1% level based on Student’s t-test of mean number of successful matings.

†Only males paired with two live healthy females have been included

 

In week 7, the significant decrease in the number of males mating with both females in the 1000 ppm test substance group can be explained by two factors: unusually high control values (100% of males mated with both females) and by two males which mated with only one or neither of the two females because of health reasons. One of these males was found to have an abscess on the penis and, retrospectively, it can be seen that from week 4 of mating (abscess first detected week 5) until week 7 when it was killed, the animal failed to mate with any of the females with which it was paired. After both animals had been killed in week 7, 100% of the males in this group mated with both females the following week. It should also be stressed that despite any statistical differences, the fertility in the test substance treated groups remained high throughout the experiment, while the two positive control groups showed definite fertility effects due to treatment in the early weeks of the experiment. The significant effects in the EMS group in weeks 7 and 8 were again probably influenced by the negative control values while those for weeks 6, 7, and 8 in the CTX group were probably an indirect effect caused by the delayed toxicity of CTX since several males died during this time and presumably did not mate before they died.

 

Implantations: Analysis of the numbers of implantations per pregnancy revealed no significant effects in the test substance groups. Both positive controls EMS and CTX produced very significantly reduced mean numbers of implantations per pregnancy in weeks 1 and 2. The effect of CTX was also apparent in weeks 3 and 6.

 

Early Deaths: Early deaths which are the most sensitive indicator or mutagenicity in the dominant lethal test were statistically significantly increased in the group of male mice exposed to the top dose of the test substance in weeks 4 and 8, while in week 7 the pooled value for all three test substance treated groups was significantly higher than that of the negative control. The actual increases, especially when compared to the positive control values in weeks 1 and 2 were very small. On examination of the negative control data, it was seen that at weeks 4, 7 and 8 the numbers of early deaths were particularly low. Furthermore except when the percentage of pregnant females with at least one early death was considered, the values found to be statistically significant for the test substance treated groups fell within the range obtained for the negative control group. That these effects were due to low negative control values was also borne out by the statistically significant increases in the positive control groups in weeks 4, 7, and 8 which have not been seen in previous studies which showed a good degree of correlation. A subsequent experiment using cyclophosphamide (CTX) did, however, show a slight increase in week 4. There was no effect on the number of implantations in the test substance treated groups and it is usual for pre- and post-implantation loss to be associated with a mutagenic effect, as was demonstrated by the positive controls.

 

Late deaths: The proportion of females with late deaths showed a significant increase in the 10000 ppm test substance group. Since this was an isolated finding which did not show a dose response it was unlikely to have been treatment related and was slightly greater than a value observed before treatment in one of the groups.

 

Conclusion: The test substance had no effect on fertility and is unlikely to cause mutagenic effects as assessed by the mouse dominant lethal assay.

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 0, 1000, 10000 or 50000 ppm test substance 6 hours a day for 5 days. Positive control groups received either 5 daily oral doses of ethyl methanesulphonate or a single intraperitoneal dose of cyclophosphamide. 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.

Despite occasional statistical differences between the test substance and the negative control groups, this study indicated that the test substance does not did not affect male fertility or cause mutagenic effects through sperm. This lack of effect was not due to a lack of sensitivity of the test system since the expected positive responses were demonstrated by ethyl mehtanesulphonate and cyclophosphamide. The NOAEC for this study was >50000 ppm.

Effect on fertility: via inhalation route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
210 000 mg/m³
Species:
rat
Additional information

No reproductive toxicity data are available for the test substance. Dominant lethal and fertility data with 1,1,1,2-tetrafluoroethane (HFC 134a) were used as a read-across to fulfill the data gap for the test substance. The underlying hypothesis for the read-across between the test substance and HFC 134a is that the substances are structurally similar and possess similar physicochemical properties that account for their poor absorption in the body, neither has significant acute or subchronic toxicity (including histopathological effect on reproductive organs) event at the highest concentrations tested, and are not classified as hazardous to health. Additional documentation, provided within the IUCLID Assessment Reports section, supports the read-across approach.

In a dominant lethal assay, CD1 male mice were exposed to 0, 1000, 10000 or 50000 ppm1,1,2 -tetrafluoroethane (HFC 134a) for 6 hours a day for 5 days. This study indicated that the test substance does not did not affect male fertility or cause mutagenic effects through sperm. The NOAEC for this study was >50000 ppm.

1,1,2 -tetrafluoroethane (HFC 134a) was administered to AHA rats by snout only inhalation to assess the effects on reproduction and development. In the fertility element of the study, rats were exposed to atmospheres of 2500, 10000 or 50000 ppm HFC 134a for 1 hour/day 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 50000 ppm (208000 mg/m3). There were no adverse effects of HFC 134a on the fertility and reproductive performance of treated animals or on the development, maturation or reproductive performance of up to two successive generations. The NOAEL for the P, F1,and F2 generations was ≥50000 ppm.

Additionally, male and female rats were exposed to the test substance at 0, 0.2, 1, or 2.5% v/v via inhalation for 24 months. No survival or life-shortening effects were observed at any exposure concentration. No histopathological or weight changes were observed in reproductive organs at any concentration tested. Based on this information, the NOAEC was 2.5% (67485 mg/m3). 

Overall, the reproductive data from the read-across chemical, data from the 2-year inhalation study with the test substance, the poor absorption, and lack or reactivity and rapid elimination of unmetabolised test substance suggest that test substance-related reproductive toxicity via inhalation is unlikely.


Short description of key information:
NOAEC = 210000 mg/m3

Justification for selection of Effect on fertility via inhalation route:
Equivalent to OECD 478, Reliability = 2

Effects on developmental toxicity

Description of key information
NOAEC = 135000 mg/m3
Link to relevant study records
Reference
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This study was selected as the key study because the information provided for the hazard endpoint is sufficient for the purpose of classification and labelling and/or risk assessment.
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Deviations:
yes
Remarks:
Only 2 concentrations tested; dosing through day 15G (not through to the day prior to scheduled sacrifice); no food consumption data collected; no data on gravid uterus weight.
GLP compliance:
not specified
Limit test:
no
Species:
rat
Strain:
other: Charles River-CD®
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: Not reported
- Weight at study initiation: Approximately 185 g
- Fasting period before study: No
- Housing: Individually in suspended stainless steel wire-mesh cages
- Diet (e.g. ad libitum): ad libitum, except during exposures
- Water (e.g. ad libitum): ad libitum, except during exposures
- Acclimation period: Not reported

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.4-23.3°C
- Humidity (%): 50%
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): Not reported
Route of administration:
inhalation: vapour
Type of inhalation exposure (if applicable):
not specified
Vehicle:
other: Air
Details on exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 1.4 cubic meter stainless steel and glass chambers
- Method of holding animals in test chamber: Not reported
- Source and rate of air: Not reported
- Method of conditioning air: Not reported
- System of generating particulates/aerosols: The desired concentrations were generated by metering vapours of the test substance from the cylinder into 1.4 cubic meter stainless steel and glass chambers operating under dynamic airflow conditions. The control animals were exposed to room air in identical chambers.
- Temperature, humidity, pressure in air chamber: Not reported
- Air flow rate: Not reported
- Air change rate: Not reported
- Treatment of exhaust air: Not reported

TEST ATMOSPHERE
- Brief description of analytical method used: Chamber atmospheres were monitored every 30 minutes using Teflon® lines connected to a gas chromatograph fitted with a sample loop injection and stream selection valve. The GC was calibrated daily with gaseous standards.
- Samples taken from breathing zone: yes
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Chamber atmospheres were monitored every 30 minutes via gas chromatograph (GC). The GC was calibrated daily with gaseous standards. The daily average analytical exposure levels during the entire 10-day exposure period were 5300 ± 1200 and 45300 ± 4900 ppm.
Details on mating procedure:
- Impregnation procedure: purchased timed pregnant; the morning when sperm were found in the vaginal smear was counted as Day 1 of gestation. One-half of the females were bred on Day 0 and the other half on Day 0 + 2. All females were received in one shipment as 4 and 2 days pregnant.
Duration of treatment / exposure:
6 hours/day
Frequency of treatment:
Days 6 - 15 of gestation
Remarks:
Doses / Concentrations:
5000 and 50000 ppm
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
5300±1200 and 45300±4900 ppm
Basis:
analytical conc.
No. of animals per sex per dose:
27 female rats per dose
Control animals:
yes, concurrent vehicle
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily

BODY WEIGHT: Yes
- Time schedule for examinations: On day of receipt, when first exposed, twice weekly during exposure, and day of sacrifice

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No

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

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 21
- Organs examined: Ovaries, uterine horns, vital organs and tissues
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
- Foetal Weight and crown-rump length of all live foetuses
- External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]
- Head examinations: Yes: [half per litter]
Statistics:
For statistical evaluation of the data, the litter was considered the experimental unit of treatment and observation. The Fisher Exact probability test was used to evaluate the incidence of resorptions and abnormalities among litters. Maternal and foetal body weights and foetal crown-rump measurements were treated statistically by analysis of variance and least significant difference (LSD) tests. The number of corpora lutea, implantations, and live foetuses per litter were analyzed by the Wilcoxon rank sum test. In all cases, two-tailed significance tests were performed and significance was judged at the 0.05 probability level.
Details on maternal toxic effects:
Maternal toxic effects:no effects
Dose descriptor:
NOAEC
Effect level:
50 000 ppm (nominal)
Basis for effect level:
other: maternal toxicity
Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Petechial haemorrhages and small subcutaneous hematomas on various parts of the body and the number of runts among litters and foetuses were similar in all groups. Apparent hydronephrosis, transposition of the viscera, liver peliosis, and internal haemorrhage were detected; however, none of these findings were considered to be treatment-related.
Dose descriptor:
NOAEC
Effect level:
50 000 ppm (nominal)
Basis for effect level:
other: teratogenicity
Abnormalities:
not specified
Developmental effects observed:
not specified

A summary of other reproductive outcomes (means/litter) are provided in the table below:

 Concentration (ppm)

0

 5000  

 50000  

 Corpora lutea:

11.6

 11.3  

 12.2  

 Implantations:

10

 9.4  

 10.5  

 No. of Resorptions:

1.5

 1.4  

 1.2  

 Total No. of Foetuses: 

9.3

 8.8  

 9.9  

 Total No. of Live Foetuses:

9.3

 8.8  

 9.9  

 Mean Foetal Weight (g):

4.3

 4.4  

 4.3  

 Sex Ratio:

NR

 NR  

 NR  

NR = Foetal sex was not recorded; therefore, sex ratios could not be calculated.  

 

 

A summary of gross, soft tissue, and skeletal anomalies are provided in the table below. Data are presented as number of litters (foetuses) affected:

Concentration (ppm)  

 0  

 5,000  

 50,000  

 Gross External,

 Number examined:  

 22(205)  

  20(184)  

 19(188)  

 Petechial haemorrhages

 4(4)  

 5(5)  

 3(5)  

 Hematoma  

 10(12)  

 6(7)  

 8(14)  

 Runts  

 2(2)  

 1(1)  

 1(1)  

 Soft Tissue,

 Number examined:  

 22(105)  

 20(93)  

 19(90)  

 Hydronephrosis  (apparent)  

 1(1)  

 3(4)  

  2(2)  

 Situs inversus  

 0  

 0  

  1(1)  

 Liver peliosis  

 0  

 0  

  3(3)  

 Internal haemorrhage  

 1(1)  

 0  

 0  

 Skeletal,

 Number examined:

 22(100)  

 20(91)  

 19(98)  

 14th rudimentary rib  

 16(51)  

 16(53)  

 19(69)  

 Wavy ribs  

 8(17)  

 6(8)  

  5(7)  

 Sternebrae unossified  

 10(14) 

  9(16)  

 12(23)  

 Bipartite centra  

 3(3)  

 0  

  2(2)  

 Hyoid unossified  

 2(3)  

 0  

  4(6)  

 

Conclusions:
The study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability). The NOEC for maternal and developmental toxicity was 50000 ppm, the highest level tested.
Executive summary:

Pregnant rats were exposed to nominal concentrations of 0, 5000, and 50000 ppm of the test substance for 6 hours per day on Days 6 through 15 of gestation. The animals were observed daily for signs of toxicity and changes in demeanour and behaviour. They were weighed on days they were received, when first exposed, twice weekly during the exposure and on the day of sacrifice. 

Inhalation exposure did not produce clinical signs of toxicity or changes in behaviour in pregnant rats exposed for 6 hours daily on Days 6 through 15 of gestation. The outcome of pregnancy measured by the number of corpora lutea, implantation sites, resorptions, and live foetuses per litter, was not adversely affected by the treatment. The exposures did not affect embryonal development as measured by weight, crown-rump length, and gross external, visceral, and skeletal examination of the foetuses. Under the conditions of this study, the test substance was not embryotoxic or teratogenic in rats. The NOEC for maternal and developmental toxicity was 50000 ppm, the highest dose tested.

Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
135 000 mg/m³
Study duration:
subacute
Species:
rat
Additional information

Rats were evaluated in a developmental toxicity via inhalation concentrations up to and including 50000 ppm. No maternal or developmental toxicity was observed at the highest concentration tested, therefore, the NOAEC was 50000 ppm (135000 mg/m3).

Although developmental toxicity studies in rats are available, no developmental toxicity studies in rabbits are available for the test substance. Developmental toxicity studies in rabbits with 1,1,1,2-tetrafluoroethane (HFC 134a), 1,1,1-trifluoroethane (HFC-143a), and 1,1,1,2,2-pentafluoroethane (HFC-125) were used as a read-across to fulfill the data gap for the test substance. The underlying hypothesis for the read-across between the test substance and the read across substances is that the substances are structurally similar and possess similar physicochemical properties that account for their poor absorption in the body, all have no significant acute or subchronic toxicity (including histopathological effect on reproductive organs) event at the highest concentrations tested, and none are classified as hazardous to health. Additional documentation, provided within the IUCLID Assessment Reports section, supports the read-across approach.

A developmental toxicity study with 1,1,1,2 -tetrafluoroethane (HFC 134a) was conducted. HFC-134a was administered via inhalation to groups of female rabbits on days 7-19 of gestation at exposure levels of 0, 2500, 10000 and 40000 ppm. Exposure to concentrations of ≥10000 ppm was associated with slight maternal toxicity manifest as reduced body weight gain and food consumption. There was no evidence of maternal toxicity at 2500 ppm. There was no evidence of embryotoxicity, teratogenicity or foetotoxicity at any exposure level. The NOEC was 2500 ppm (10500 mg/m3) for maternal toxicity and 40000 ppm (168000 mg/m3) for embryotoxicity and fetotoxicity.

A developmental toxicity study with 1,1,1-trifluoroethane (HFC-143a) was conducted. HFC-143a was administered via inhalation to groups of 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 40000 ppm (136000 mg/m3) for the dam and conceptus.

A developmental toxicity study with pentafluoroethane (HFC-125) was conducted. HFC-125 was administered via inhalation to groups of female rabbits on days 6 -18 of gestation at exposure levels of 0, 5000, 15000, and 50000 ppm. There was no evidence of maternal or developmental toxicity at any level tested. The NOEC was greater than 50000 ppm (245000 mg/m3) for the dam and conceptus.


Justification for selection of Effect on developmental toxicity: via inhalation route:
Equivalent to OECD 414, rat, Reliability = 2

Justification for classification or non-classification

The test substance did not adversely affect reproductive organs and was not uniquely toxic to the developing foetus. Additional developmental and reproductive data from read-across substances support the conclusion that the test substance is not expected to be a developmental or reproductive toxin. Therefore, the substance does not need to be classified for reproductive toxicity according the EU Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.