Dichlorodifluoromethane

Endpoint summary

Key value for chemical safety assessment

Toxic effect type:

concentration-driven

Effects on fertility

Description of key information

No adverse effects were reported regarding reproductive parameters and/or reproductive organs based on tests conducted by the oral (3-generation study) and/or inhalation routes (2-year repeated dose toxicity study). There was no dominant lethal effect indicating no specific concern for male reproduction.

Link to relevant study records

Reference

Reference 1

Endpoint:

three-generation reproductive toxicity

Remarks:

based on test type

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

The primary report was not available for review but the data has been reviewed by the World Health Organisation (WHO) experts who have agreed that no effects or dominant lethality was found at either dose level tested.

Qualifier:

no guideline followed

Principles of method if other than guideline:

In a three-generation, oral gavage study in rats using CFC-12 (in corn oil) at average doses of 15 and 150 mg/kg per day. Limited details available but the data has been reviewed by the World Health Organisation (WHO) experts.

GLP compliance:

not specified

Remarks:

likely pre-dates the GLP standards

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

Charles River CD

Sex:

male/female

Details on test animals or test system and environmental conditions:

Not specified

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

In a three-generation, oral gavage study in rats using CFC-12 (in corn oil) at average doses of 15 and 150 mg/kg per day

Details on mating procedure:

Not specified

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

Not specified

Duration of treatment / exposure:

Not specified

Frequency of treatment:

Not specified

Details on study schedule:

Not specified

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

15 mg/kg bw/day (nominal)

Dose / conc.:

150 mg/kg bw/day (nominal)

No. of animals per sex per dose:

50 /sex/dose

Control animals:

yes, concurrent vehicle

Details on study design:

Male and female rats were given Freon 12 in doses of 15 or 150 mg/kg by intubation. The rats were then bred and evaluated for fertility, corpora lutea, implantation sites, resorption sites, and number of live fetuses per litter.

Groups of 50 males and 50 females of the F1a generation remained in the test for 2 years, with an interim killing at 1 year.
Animals received CFC-12 in corn oil or corn oil alone daily by gavage for 6 weeks, and 5 times/week thereafter.

Dominant Lethal assay, part of a reproductive toxicity study:
The F0 animals of the reproduction study were mated to initiate an F1b litter. Animals were treated with the test substance gavage until pregnancies were terminated in mid-term to give a dominant lethal assay

Positive control:

Not specified (not required)

Parental animals: Observations and examinations:

Not specified

Oestrous cyclicity (parental animals):

Not specified

Sperm parameters (parental animals):

Not specified

Litter observations:

Not specified

Postmortem examinations (parental animals):

Not specified

Postmortem examinations (offspring):

Not specified

Statistics:

Not specified

Reproductive indices:

Fertility, corpora lutea, implantation sites, resorption sites, and number of live fetuses per litter.

Offspring viability indices:

Number of live fetuses per litter.

Clinical signs:

not specified

Mortality:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not specified

Other effects:

not specified

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

no effects observed

Description (incidence and severity):

No effects on fertility index (percentage of matings resulting in pregnancy), no effects on gestation index (% of pregnancies resulting in birth of liver litters).

No dominant lethality was found at either dose level.

Key result

Dose descriptor:

NOEL

Effect level:

> 150 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

(limited details available)

Clinical signs:

no effects observed

Description (incidence and severity):

No overt signs of toxicity.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

no significant differences between treated and control groups in survival and post-natal survival (survival after 4 days or 21 days)

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

in F1a parental generation (treatment started at 6 weeks of age): Body weight gain was depressed in the high-dose groups, particularly among the females.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

Slight decline in food efficiency in high dose females, compared to controls

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

no effects observed

Description (incidence and severity):

No effects reported on fertility index of the second parental generation

No details provided on the unpublished study report reviewed by WHO.

Key result

Dose descriptor:

NOAEL

Effect level:

> 150 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

(limited details available)

Key result

Critical effects observed:

no

Clinical signs:

not specified

Description (incidence and severity):

No effects on viability index (percentage of rats born that survived four days)
No effects on lactation index (percentage of rats alive at 4 days that survived to be weaned at 21 days)

Body weight and weight changes:

not specified

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Histopathological findings:

not specified

Other effects:

no effects observed

Description (incidence and severity):

No dominant lethality was found at either dose level, indicating no chromosomal damage to germ cells.

Behaviour (functional findings):

not specified

No dominant lethality was found at either dose level.

Key result

Dose descriptor:

NOEC

Generation:

F1

Effect level:

>= 150 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

No effects reported on the reproductive parameters of the F1 generation and no effects on postnatal survival

Key result

Critical effects observed:

no

Key result

Reproductive effects observed:

no

Conclusions:

No dominant lethality was found at either dose level.
The substance is not considered to be classified for fertility effects.

Executive summary:

In a 3-generation oral study using CFC12 (in corn oil) at average doses of 15 and 150 mg/kg per day, Sherman (1974) found no adverse effects in reproductive capability as measured by the fertility index, gestation index, viability index and lactation index. No classification is applicable.

Reference 2

Endpoint:

extended one-generation reproductive toxicity - basic test design (Cohorts 1A, and 1B without extension)

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because a two- (or multi-) generation reproductive toxicity study is available

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
Available data in multi-generation experimental study did not indicate adverse effects on reproduction. There was no dominant lethal effect in rats. In chronic studies in rats and mice, no histopathological lesions were reported in the reproductive organs (uterus and gonads) that were examined.
The use of this substance is regulated (Regulation (EC) No. 1005/2009) with limited volumes allowed for the listed use. The process is fully automated and operated remotely, and technical measures are set up to prevent and minimise potential emissions as reported in the CSR.
Existing information in the dataset support a low toxicity profile of the substance, with no specific alerts for fertility or reproduction parameters. There are no consumer uses. As use volumes are controlled and regularly lowered by the Regulation, additional animal tests are not considered necessary

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

In a 3-generation oral study using CFC12 (in corn oil) at average doses of 15 and 150 mg/kg per day, Sherman (1974) found no adverse effects in reproductive capability as measured by the fertility index, gestation index, viability index and lactation index. 

This study has been reviewed by the World Health Organisation (WHO) and international experts have agreed that no effects or dominant lethality was found at either dose level tested. 

Effects on developmental toxicity

Description of key information

No effects were observed on fetal development in rats or rabbits exposed by the oral or inhalation routes.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Study report, not conducted to GLP but well documented with methodology and results included.

Qualifier:

no guideline followed

Principles of method if other than guideline:

See "details on exposure" and "details on test animals and environmental conditions" below.

GLP compliance:

not specified

Remarks:

prior to GLP standards

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Charles River-CD

Details on test animals or test system and environmental conditions:

Seventy-eight pregnant (primigravida) albino rats (Charles River-CD) were received from Charles Rivers Breeding Laboratories in two shipments one day apart. From the time of arrival at Haskell Laboratory through the fifth day of gestation, the animals were housed in suspended stainless steel wire cages, assigned to three groups, and fed Ground Purina Laboratory Chow (GPLC) supplemented with 1% corn oil (CO).

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

On day six of the gestation period, all rats in all groups were given the following diet: 74.25% GPLC + 0.25% CO + 25% Casein + 0.5% vitamin mix. One group, the control, was given 2.0ml of corn oil each day by intragastric intubation for 10 consecutive days; the other two groups were given 2.0ml of Haskell No. 6966 (0.2% solution of Freon 12 in corn oil) or Haskell No. 6967 (2.0% solution of Freon 12 in corn oil), respectively, for the same period of time, i.e., through day 15 of gestation. From day 16 of the gestation period to the time of sacrifice, the control and test rats received their initial basal diet (GPLC + 1% CO).

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

Not specified

Details on mating procedure:

Not specified

Duration of treatment / exposure:

10 days (gestation day 6 to gestation day 15)

Frequency of treatment:

Daily

Duration of test:

To day 21 of gestation period.

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

16.6 mg/kg bw/day (nominal)

Dose / conc.:

170.9 mg/kg bw/day (nominal)

No. of animals per sex per dose:

78 rats in total.
Group I (0) - 25
Group II (16.6) - 26
Group III (170.9) - 27

Control animals:

yes, concurrent vehicle

Details on study design:

The animals were sacrificed by chloroform inhalation on the twenty-first day of gestation. Pregnancy was dated by counting as day one the morning on which a copulation plug was found. An incision was made in the abdominal wall and both ovaries and uterine horns were promptly removed, inspected and weighed. The uterus was carefully opened and the foetuses removed. The following observations and measurements were made:
1. Number and location of live foetuses, dead foetuses, and resorption sites in the respective uterine horns.
2. Body weight and crown-rump length of all live foetuses.
3. External examination of all foetuses, from head to tail, under Macro Scope (Ednakite 2½ x) for gross abnormalities.
About two-thirds of the foetuses from each litter were preserved in 95% alcohol for subsequent maceration in 1% aqueous KOH, clearing and staining with Alizarin Red S, and examination to detect skeletal abnormalities. The remaining foetuses were fixed in Bouin’s fluid for free-hand razor-blade sectioning (Wilson Method) and examination for visceral and neural anomalies under the dissecting microscope.

Maternal examinations:

Not specified

Ovaries and uterine content:

An incision was made in the abdominal wall and both ovaries and uterine horns were promptly removed, inspected and weighed. The uterus was carefully opened and the foetuses removed.

Fetal examinations:

Number and location of live foetuses, dead foetuses, and resorption sites in the respective uterine horns. Body weight and crown-rump length of all live foetuses. External examination of all foetuses, from head to tail, under Macro Scope (Ednakite 2½ x) for gross abnormalities.

Statistics:

Not specified

Indices:

Not specified

Historical control data:

The data was also compared with the standard values established for Charles River-CD (ChR-CD) rats.

Clinical signs:

no effects observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Details on maternal toxic effects:

Maternal toxic effects: no effects

Body Weight: The oral administration of Freon 12 to pregnant rats during the period of organogenesis had no adverse effect on body weight gain
Food Consumption: There were no meaningful differences among the control and test groups of rats with respect to food intake during any of the time periods measured.
Pregnancy Outcome : The uteri of all females in all groups were free from gross abnormalities. There was no difference in the numbers of implantation sites, viable foetuses and resorption sites per female between the control group and those given Freon 12.

Key result

Dose descriptor:

NOAEL

Effect level:

>= 171 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

food consumption and compound intake

mortality

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects: no effects

Details on embryotoxic / teratogenic effects:
Pregnancy Outcome and Fetal Development: The uteri of all females in all groups were free from gross abnormalities. There was no difference in the numbers of implantation sites, viable foetuses and resorption sites per female between the control group and those given Freon 12. Likewise, there was no significant difference in mean weight and length of foetuses. The smaller weight and length in the control group were due to sacrifice of several females on day earlier (20 days). The data was also compared with the standard values established for Charles River-CD (ChR-CD) rats and were found to be in good agreement.
Malformations and Anomalies: No major gross, skeletal or soft tissue abnormalities were detected. Maternal feeding of Freon 12 did not influence the fetal development. The incidence and type of other minor anomalies were compared with those of the control group and with the standard values for ChR-CD rats. They were found to be similar.

Key result

Dose descriptor:

NOAEL

Effect level:

> 170 mg/kg bw/day (actual dose received)

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

TABLE I – AVERAGE BODY WEIGHTS OF PREGNANT RATS RECEIVING FREON 12 DURING ORGANOGENESIS

Group Characteristics	No. of Pregnant Rats No. of Rats Received	Average Body Weight in Grams on Day of Gestation Period
		6	16	21
2 ml corn oil (control)	22/25	199	269	337
2 ml corn oil containing 0.2% Freon 12 (test)	20/26	203	278	345
2 ml corn oil containing 2.0% Freon 12 (test)	25/27	196	271	346

 

TABLE II – AVERAGE FOOD CONSUMPTION DATA OF PREGNANT RATS RECEIVING FREON 12 DURING ORGANOGENESIS

Group Characteristics	No. of Pregnant Rats No. of Rats Received	Average Daily Food Consumption (g/rat/day)
		Control Diet Prior to Day 6	Diet During Dosing Day 6-16	Control Diet Days 16-21
2 ml corn oil (control)	22/25	17.1	17.0	21.0
2 ml corn oil containing 0.2% Freon 12 (test)	20/26	18.7	19.3	22.7
2 ml corn oil containing 2.0% Freon 12 (test)	25/27	17.4	17.8	23.1

 

TABLE III – AVERAGE DOSE OF FREON 12 RECEIVED BY PREGNANT RATS DURING ORGANOGENESIS

Group Characteristics	Average Body Weight In Grams During Day 6-16	Average Dose of Freon 12 (mg/kg/day)
2 ml corn oil (control)	234	-
2 ml corn oil containing 0.2% Freon 12 (test)	241	16.6
2 ml corn oil containing 2.0% Freon 12 (test)	234	170.9

 

TABLE IV – EFFECT OF ORAL ADMINISTRATION OF FREON 12 TO PREGNANT RATS IN THE OUTCOME OF PREGNANCY AND ON VARIOUS PARAMETERS OF FETAL DEVELOPMENT

	Groups (mg/kg/day of Freon 12)			Standard Values (Range) for Charles River (CD) Rats (1)
	Group I (0)	Group II (16.6)	Group III (170.9)
Number Females Pregnant	22/25 (88.0%)	20/26 (76.9%)	25/27 (92.6%)	90% (62-100)
Number Implantation Sites	201	186	236
Number Implantation Sites / Pregnant Female	9.13	9.30	9.44	10.9 (8.6-14.1)
Number Live Fetuses	197	179	231
Number Dead Fetuses	0	0	0
Number of Live Fetuses/Litter	8.95	8.95	9.24	10.2 (8.2-12.7)
Number Females Showing Complete Resorption	0	0	0	0.3% (0-5.9)
Number Females Showing Premature Birth	0	0	0	0.1% (0-5.9)
Number Females Showing Partial Resorption (Excluding Complete Resorptions)	4 (18.2%)	4 (20.0%)	3 (12.0%)	40.6% (10.5-77.8)
Total Number Resorbed	4 (2.0%)	7 (3.8%)	5 (2.1%)	6.0% (1.2-12.4)
Mean Fetus Weight (g)	3.35	4.19	3.93	3.69 (2.90-4.22)
Mean Fetus Crown-Rump Length (cm)	2.98	3.52	3.36

(1) Personal communication; unpublished data obtained from Charles River Breeding Laboratories, Wilmington, Massachusetts for period 1964 -1969.  

 

TABLE V – GROSS EXTERNAL, SKELETAL AND SOFT TISSUE ABNORMALITIES FOUND IN FETUSES FROM MOTHERS ADMINISTERED FREON 12 DURING FETAL DEVELOPMENT

Abnormalities Found	Groups (mg/kg/day of Freon 12)			Standard Values (Range) of Abnormalities for ChR-CD Rats (1)
	Group I (0)	Group II (16.6)	Group III (170.9)
1. Gross External
Number Fetuses Examined	197	179	231	32915
a. Small, stunted	1 (0.5%)	0 (0%)	4 (1.73%)	0.3% (0-3.5)
2. Skeletal
Number Fetuses Examined	12	117	154	7127
a. Xiphisternum and one or more sternebrae unoissified	10 (7.7%)	10 (8.5%)	17 (11.0%)	11% (5-30)
b. With 14 rib(s)	15 (11.7%)	9 (7.6%)	12 (7.8%)	21% (6.36)
c. Vertebral bipartite centra	1 (0.8%)	1 (0.9%)	0 (0%)	2% (0-4)
3. Soft Tissue (Visceral and Neural)
Number Fetuses Examined	68	*	77
a. Found normal	68	-	77

(1) Personal communication; unpublished data obtained from Charles River Breeding Laboratories, Wilmington, Massachusetts for period 1964 -1969.

* Not examined.

Conclusions:

Maternal feeding of CFC-12 was not embryotoxic under the conditions of this experiment. CFC-12 was not teratogenic.

Executive summary:

The present study was undertaken, as part of a comprehensive toxicological program, to evaluate the embryotoxic and teratogenic potential, if any, of CFC-12 when it was administered by intragastric intubation to pregnant rats during the period of fetal organogenesis. 

Gastric intubation of dichlorodifluoromethane (CFC-12) to pregnant rats from day six through day fifteen of their gestation period, at average dose levels of 16.6 and 170.9 mg/kg/day, had no effect on the food intake and the gain in body weight of the mothers.

No clinical signs of toxicity were observed in any of the treated animals. The outcome of pregnancy, measured by the number of implantation sites, resorptions and live foetuses per litter, was not adversely affected by the treatment. The treatment did not affect the embryonal development as measured by weight and crown-rump length of the foetuses. The absence of any major external, skeletal, and soft tissue abnormalities in live foetuses and a similar incidence of spontaneous minor anomalies in the control and treated groups indicate that oral administration for CFC-12 was not teratogenic.

CONCLUSIONS

The absence of any effect on the number of implantation sites, resorptions, live foetuses per litter and mean weight and crown-rump length of the foetuses indicate that maternal feeding of CFC-12 was not embryotoxic under the conditions of this experiment.

Likewise, the absence of any major abnormalities in live foetuses and a similar incidence of spontaneous minor anomalies in the control and treated groups indicate that CFC-12 was not teratogenic.

Reference 2

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Principles of method if other than guideline:

Summary only.

GLP compliance:

not specified

Limit test:

yes

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

pregnant females

Route of administration:

inhalation

Type of inhalation exposure (if applicable):

not specified

Vehicle:

air

Details on exposure:

Not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Animals inseminated

Duration of treatment / exposure:

Rats: gestation day 4 to 16

Frequency of treatment:

2 hours per day.

Duration of test:

Half of the Rats were sacrificed on day 20 of gestation, the rest were allowed to deliver

Dose / conc.:

200 000 ppm (nominal)

Remarks:

eq. to 20% concentration of a mixture of CFC-11 (10%) and CFC-12 (90%) in air
(i.e., approx. 180000 ppm CFC-12)

No. of animals per sex per dose:

20 female rats

Control animals:

not specified

Details on study design:

Inseminated Wistar albino rats were administered a mixture of 90% CFC-12 (dichlorodifluoromethane) and 10% Freon 11 by inhalation for 2hr/day. Pregnant rats were exposed on days 4 to 16 of gestation. The mixture was administered in a 20% concentration (200,000 ppm).

Maternal examinations:

DETAILED CLINICAL OBSERVATIONS: no data

BODY WEIGHT: Yes

Ovaries and uterine content:

Not specified

Fetal examinations:

Yes, but no details provided

Clinical signs:

not specified

Mortality:

not specified

Body weight and weight changes:

no effects observed

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

not specified

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Changes in pregnancy duration:

not specified

Details on maternal toxic effects:

Maternal toxic effects: no effects

Key result

Dose descriptor:

NOEC

Effect level:

> 200 000 ppm (nominal)

Based on:

test mat.

Remarks:

(mixture of 10% CFC-11 and 90% CFC-12)

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

No effects on survival at birth

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

no effects observed

Description (incidence and severity):

No effects on survival after 1 and 4 weeks

External malformations:

no effects observed

Description (incidence and severity):

No details on examinations performed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects: no effects reported.
Limited details available on teratogenicity examination.

Key result

Dose descriptor:

NOEC

Effect level:

>= 200 000 ppm

Based on:

test mat.

Basis for effect level:

other: No embryotoxicity or fetotoxicity observed at that concentration

Remarks on result:

not determinable due to absence of adverse toxic effects

Abnormalities:

no effects observed

Description (incidence and severity):

(limited details available)

Key result

Developmental effects observed:

no

No indications of any embryotoxic, fetotoxic, or teratogenic changes were found when dams were sacrificed and foetuses removed on day 20 of gestation (rats).

Conclusions:

No indications of any embryotoxic, fetotoxic, or teratogenic changes were found in the offspring of rats exposed during gestation days 4 to 16.

Executive summary:

In studies of inseminated Wistar albino rats, Paulet et al. (1974) administered a mixture of 90% CFC-12 (dichlorodifluoromethane) and 10% Freon 11 by inhalation for 2hr/day. Rats were exposed on days 4 to 16 of gestation. The mixture was administered in a 20% concentration (200,000 ppm). No indications of any embryotoxic, fetotoxic, or teratogenic changes were found when dams were sacrificed and foetuses removed on day 20 of gestation (rats). No classification is applicable.

Reference 3

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

WHO assessment.

Principles of method if other than guideline:

Summary only.

GLP compliance:

not specified

Limit test:

yes

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

Not specified

Route of administration:

inhalation

Type of inhalation exposure (if applicable):

not specified

Vehicle:

air

Details on exposure:

Not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Not specified

Duration of treatment / exposure:

Rabbits: Exposure on days 5-20 of gestation

Frequency of treatment:

2 h/day

Duration of test:

Not specified

Dose / conc.:

200 000 ppm (nominal)

Remarks:

of a mixture of 10% CFC-11 and 90% CFC-12
eq. to 20% concentration of a mixture of CFC-11 (10%) and CFC-12 (90%) in air (i.e., approx. 180000 ppm CFC-12)

No. of animals per sex per dose:

Not specified

Control animals:

not specified

Details on study design:

Not specified

Maternal examinations:

Not specified

Ovaries and uterine content:

Not specified

Fetal examinations:

Not specified

Statistics:

Not specified

Indices:

Not specified

Historical control data:

No data

Details on maternal toxic effects:

Maternal toxic effects:no data

Remarks on result:

not determinable

Remarks:

no details available on maternal toxicity

Abnormalities:

not specified

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
No evidence of embryotoxicity, fetotoxicity, or teratogenicity was seen when rabbits were sacrificed at 30 days of gestation. In addition, offspring of the dams that were allowed to deliver naturally showed no evidence of toxicity relative to survival or growth.

Dose descriptor:

NOAEC

Effect level:

>= 200 000 ppm

Based on:

test mat.

Sex:

not specified

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

no embryotoxicity, fetotoxicity or teratogenicity at the highest concentration tested

Abnormalities:

no effects observed

Developmental effects observed:

no

Conclusions:

In conclusion, CFC-12 did not show any evidence of reproductive or developmental toxicity in rabbits.

Executive summary:

In a study of a mixture (10% CFC-11 and 90% CFC-12), groups of rats and rabbits were exposed by inhalation on days 4-16 (rats) or days 5-20 (rabbits) of gestation for 2 h/day at a concentration of 989 g/m³(200 000 ppm). No evidence of embryotoxicity, fetotoxicity, or teratogenicity was seen when rats and rabbits were sacrificed at 20 days (rats) or 30 days (rabbits) of gestation. In addition, offspring of the dams that were allowed to deliver naturally showed no evidence of toxicity relative to survival or growth (US EPA, 1983).

 

In conclusion, CFC-12 did not show any evidence of reproductive or developmental toxicity.

Reference 4

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

WHO assessment.

Principles of method if other than guideline:

Summary only.

GLP compliance:

not specified

Limit test:

yes

Species:

rat

Strain:

not specified

Details on test animals or test system and environmental conditions:

Not specified

Route of administration:

inhalation

Type of inhalation exposure (if applicable):

not specified

Vehicle:

air

Details on exposure:

Not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Not specified

Duration of treatment / exposure:

Rats: Exposure on days 4-16 of gestation

Frequency of treatment:

2 h/day

Duration of test:

Not specified

Dose / conc.:

200 000 ppm (nominal)

Remarks:

of a mixture of 10% CFC-11 and 90% CFC-12
eq. to 20% concentration of a mixture of CFC-11 (10%) and CFC-12 (90%) in air (i.e., approx. 180000 ppm CFC-12)

No. of animals per sex per dose:

Not specified

Control animals:

not specified

Details on study design:

Not specified

Maternal examinations:

Not specified

Ovaries and uterine content:

Not specified

Fetal examinations:

Not specified

Statistics:

Not specified

Indices:

Not specified

Historical control data:

No data

Details on maternal toxic effects:

Maternal toxic effects:no data

Remarks on result:

not determinable

Remarks:

no details available on maternal toxicity

Abnormalities:

not specified

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects: no effects

Details on embryotoxic / teratogenic effects:
No evidence of embryotoxicity, fetotoxicity, or teratogenicity was seen when rats and rabbits were sacrificed at 20 days (rats) or 30 days (rabbits) of gestation. In addition, offspring of the dams that were allowed to deliver naturally showed no evidence of toxicity relative to survival or growth.

Dose descriptor:

NOAEC

Effect level:

>= 200 000 ppm

Based on:

test mat.

Sex:

not specified

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

No reported effects on embryotoxicity, fetotoxicity, fetal malformations

Abnormalities:

no effects observed

Developmental effects observed:

no

Conclusions:

In conclusion, CFC-12 did not show any evidence of reproductive or developmental toxicity in rats.

Executive summary:

In a study of a mixture (10% CFC-11 and 90% CFC-12), groups of rats and rabbits were exposed by inhalation on days 4-16 (rats) or days 5-20 (rabbits) of gestation for 2 h/day at a concentration of 989 g/m³(200 000 ppm). No evidence of embryotoxicity, fetotoxicity, or teratogenicity was seen when rats and rabbits were sacrificed at 20 days (rats) or 30 days (rabbits) of gestation. In addition, offspring of the dams that were allowed to deliver naturally showed no evidence of toxicity relative to survival or growth (US EPA, 1983).

 

In conclusion, CFC-12 did not show any evidence of reproductive or developmental toxicity.

Reference 5

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Principles of method if other than guideline:

Summary only.

GLP compliance:

not specified

Limit test:

yes

Species:

rabbit

Strain:

not specified

Remarks:

albino rabbits

Details on test animals or test system and environmental conditions:

pregnant females

Route of administration:

inhalation

Type of inhalation exposure (if applicable):

not specified

Vehicle:

air

Details on exposure:

Not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Animals inseminated

Duration of treatment / exposure:

Rabbits: gestation day 5 to 20

Frequency of treatment:

2 hours per day.

Duration of test:

Half of the Rabbits were sacrificed on day 30 of gestation, the rest were allowed to deliver

Dose / conc.:

200 000 ppm (nominal)

Remarks:

eq. to 20% concentration of a mixture of CFC-11 (10%) and CFC-12 (90%) in air
(i.e., approx. 180000 ppm CFC-12)

No. of animals per sex per dose:

10 female rabbits

Control animals:

not specified

Details on study design:

Inseminated albino rabbits were administered a mixture of 90% CFC-12 (dichlorodifluoromethane) and 10% Freon 11 by inhalation for 2hr/day, on days 5 to 20. The mixture was administered in a 20% concentration (200,000 ppm).

Maternal examinations:

DETAILED CLINICAL OBSERVATIONS: no data

BODY WEIGHT: Yes

Ovaries and uterine content:

Not specified

Fetal examinations:

Yes, but no details provided

Clinical signs:

not specified

Mortality:

not specified

Body weight and weight changes:

no effects observed

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

not specified

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Changes in pregnancy duration:

not specified

Details on maternal toxic effects:

Maternal toxic effects: no effects

Key result

Dose descriptor:

NOEC

Effect level:

>= 200 000 ppm (nominal)

Based on:

test mat.

Remarks:

(mixture of 10% CFC-11 and 90% CFC-12)

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

No effects on survival at birth

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

no effects observed

Description (incidence and severity):

No effects on survival after 1 and 4 weeks

External malformations:

no effects observed

Description (incidence and severity):

No details on examinations performed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects: no effects reported.
Limited details available on teratogenicity examination.

Key result

Dose descriptor:

NOEC

Effect level:

>= 200 000 ppm

Based on:

test mat.

Basis for effect level:

other: No observed embryotoxicity, fetotoxicity, teratogenicity observed at that concentration

Remarks on result:

not determinable due to absence of adverse toxic effects

Abnormalities:

no effects observed

Description (incidence and severity):

(limited details available)

Key result

Developmental effects observed:

no

No indications of any embryotoxic, fetotoxic, or teratogenic changes were found when dams were sacrificed and foetuses removed on day 30 of gestation (rabbits).

Conclusions:

No indications of any embryotoxic, fetotoxic, or teratogenic changes were found in the offspring of rabbits exposed during gestation days 5 to 20.

Executive summary:

In studies with inseminated albino rabbits, Paulet et al. (1974) administered a mixture of 90% CFC-12 (dichlorodifluoromethane) and 10% Freon 11 by inhalation for 2hr/day. Rabbits were exposed on days 5 to 20. The mixture was administered in a 20% concentration (200,000 ppm). No indications of any embryotoxic, fetotoxic, or teratogenic changes were found when dams were sacrificed and foetuses removed on day 30 of gestation in rabbits. No classification is applicable.

Reference 6

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Taken from publically available data, and is considered accurate based on the registrants experience of the substance and the source as the WHO.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

Summary only.

GLP compliance:

not specified

Remarks:

Not likely (prior to GLP standards)

Limit test:

yes

Species:

rat

Strain:

other: Charles River

Details on test animals or test system and environmental conditions:

Not specified

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

Not specified

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Not specified

Duration of treatment / exposure:

Duration 10 days (dosed on days 6-15 of gestation).

Frequency of treatment:

Daily

Dose / conc.:

16.6 mg/kg bw/day (nominal)

Dose / conc.:

179 mg/kg bw/day (nominal)

No. of animals per sex per dose:

Groups of 25 to 27 pregnant rats used within the study.

Control animals:

yes, concurrent vehicle

not specified

Details on study design:

No data

Maternal examinations:

Not specified

Ovaries and uterine content:

Not specified

Fetal examinations:

Not specified

Statistics:

Not specified

Indices:

Not specified

Historical control data:

Not specified

Details on maternal toxic effects:

Maternal toxic effects:no data

Dose descriptor:

NOAEL

Effect level:

>= 179 mg/kg bw/day

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

no reported maternal toxicity

Abnormalities:

not specified

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Neither dose induced any evidence of embryotoxicity or teratogenicity.

Dose descriptor:

NOAEL

Effect level:

> 179 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

no reported embryotoxicity or teratogenicity

Abnormalities:

no effects observed

Developmental effects observed:

no

Conclusions:

In conclusion, CFC-12 did not show any evidence of reproductive or developmental toxicity.

Executive summary:

In a study, groups of 25 to 27 pregnant Charles River rats were given CFC-12 in corn oil by gavage at doses of 16.6 or 179 mg/kg per day on days 6-15 of gestation. Neither dose induced any evidence of embryotoxicity or teratogenicity (Sherman, 1974).

 

In conclusion, CFC-12 did not show any evidence of reproductive or developmental toxicity. No classification is applicable.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no adverse effect observed

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Several studies conducted in the past in rats and rabbits were available and assessed as a weight of evidence because they did not fulfill the current standards and available documentation was limited. However the studies reports cited here were reviewed by international experts as part of the International Program on Chemical Safety and summarised in the Environmental Health Criteria document No.113: Fully halogenated chlorofluorocarbons (WHO/IPCS, 1990).

http://www.inchem.org/documents/ehc/ehc/ehc113.htm#PartNumber:7

 

One of the most relevant studies was undertaken, as part of a comprehensive toxicological program, to evaluate the embryotoxic and teratogenic potential of CFC-12 when administered by intragastric intubation to pregnant rats during the period of fetal organogenesis. 

Gastric intubation of dichlorodifluoromethane (CFC-12) to pregnant rats from day six through day fifteen of their gestation period, at average dose levels of 16.6 and 170.9 mg/kg/day, had no effect on the food intake and the gain in body weight of the mothers.

No clinical signs of toxicity were observed in any of the treated animals. The outcome of pregnancy, measured by the number of implantation sites, resorptions and live foetuses per litter, was not adversely affected by the treatment. The treatment did not affect the embryonal development as measured by weight and crown-rump length of the foetuses. The absence of any major external, skeletal, and soft tissue abnormalities in live foetuses and a similar incidence of spontaneous minor anomalies in the control and treated groups indicate that oral administration for CFC-12 was not teratogenic.

 

CONCLUSIONS

The absence of any effect on the number of implantation sites, resorptions, live foetuses per litter and mean weight and crown-rump length of the foetuses indicate that maternal feeding of CFC-12 was not embryotoxic under the conditions of this experiment.

Likewise, the absence of any major abnormalities in live foetuses and a similar incidence of spontaneous minor anomalies in the control and treated groups indicate that CFC-12 was not teratogenic.

 

Other supporting studies:

In studies of inseminated Wistar albino rats and albino rabbits, Paulet et al. (1974) administered a mixture of 90% CFC-12 (dichlorodifluoromethane) and 10% Freon 11 by inhalation for 2hr/day. Rats were exposed on days 4 to 16 of gestation, and rabbits on days 5 to 20. The mixture was administered in a 20% concentration (200,000 ppm). No indications of any embryotoxic, fetotoxic, or teratogenic changes were found when dams were sacrificed and foetuses removed on day 20 of gestation (rats) or day 30 of gestation (rabbits). No classification is applicable.

 

In a study of a mixture (10% CFC-11 and 90% CFC-12), groups of rats and rabbits were exposed by inhalation on days 4-16 (rats) or days 5-20 (rabbits) of gestation for 2 h/day at a concentration of 989 g/m³(200 000 ppm). No evidence of embryotoxicity, fetotoxicity, or teratogenicity was seen when rats and rabbits were sacrificed at 20 days (rats) or 30 days (rabbits) of gestation. In addition, offspring of the dams that were allowed to deliver naturally showed no evidence of toxicity relative to survival or growth (US EPA, 1983). (possibly the same study by Paulet et al).

 

In a study, groups of 25 to 27 pregnant Charles River rats were given CFC-12 in corn oil by gavage at doses of 16.6 or 179 mg/kg per day on days 6-15 of gestation. Neither dose induced any evidence of embryotoxicity or teratogenicity (Sherman, 1974).

 

In conclusion, CFC-12 did not show any evidence of reproductive or developmental toxicity. No classification is applicable.

Justification for classification or non-classification

The above studies have all been ranked reliability 2 according to the Klimish et al system. This ranking was deemed appropriate because the studies were not conducted to GLP and are not in compliance with agreed protocols. However these are considered appropriate for use in assessment purposes in accordance with the criteria listed in Annex XI. As such, it is deemed appropriate to apply a weight of evidence approach based on similarity and animal welfare grounds.

The above results triggered no classification under the CLP Regulation (EC No 1272/2008). No classification for reproductive or developmental effects is therefore required.