Dichlorodifluoromethane

Endpoint summary

Description of key information

No adverse effects were observed in sub-chronic and chronic inhalation toxicity and carcinogenicity studies at relatively high concentrations.

- 90-day inhalation, rat: NOAEC > 10000 ppm, 49350 mg/m3

- 2-year inhalation, rat: NOAEC: 5000 ppm, 24676 mg/m3

Key value for chemical safety assessment

Toxic effect type:

concentration-driven

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

chronic toxicity: oral

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

a sub-chronic toxicity study (90 days) by the oral route does not need to be conducted because an appropriate inhalation study is available and inhalation is the most appropriate route of administration as based on the provided thorough and rigorous exposure assessment

other:

Reference 2

Endpoint:

chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Limited details available on results

Reason / purpose for cross-reference:

reference to same study

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

Charles River CD

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

corn oil

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

2 years

Frequency of treatment:

Daily

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

Control animals:

yes

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Slight body weight reduction

Key result

Dose descriptor:

NOAEL

Effect level:

>= 150 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

Remarks on result:

not determinable due to absence of adverse toxic effects

Conclusions:

No adverse effects were observed in a 2-year chronic study in rats administered 15 or 150 mg/kg/day by gavage.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

chronic toxicity: inhalation

Remarks:

(carcinogenicity)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1975 to 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Reason / purpose for cross-reference:

reference to same study

Remarks:

carcinogenicity study

Qualifier:

no guideline followed

Principles of method if other than guideline:

CFC-12 was tested by inhalation on Sprague-Dawley rats and Swiss Mice using whole body exposure. The animals were exposed by inhalation, 4 hours daily, 5 days weekly, for 104 weeks (rats: Exp. BT 601, 601 bis) and 78 weeks (mice: Exp. BT 602).
All the animals were kept under control until spontaneous death. The status and behaviour of the animals were controlled three times daily. The animals were submitted to clinical examination for gross changes every 2 weeks. The animals were weighed every 2 weeks during treatment, and then every 8 weeks. Full necropsy was performed on all the animals. The housing and the diet of the animals were the same highly standardized ones adopted in the BT Experimental Unit during the last 15 years before the beginning of this experiment.

GLP compliance:

not specified

Limit test:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source of test material: Montedison, Italy
- Purity : 99.98%

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

inhalation: gas

Type of inhalation exposure:

whole body

Vehicle:

air

Dose / conc.:

0 ppm (nominal)

Dose / conc.:

1 000 ppm (nominal)

Remarks:

eq. to 4945 mg/m3

Dose / conc.:

5 000 ppm (nominal)

Remarks:

eq. to 24676 mg/m3

No. of animals per sex per dose:

660 total (330 male & 330 female rats): 90/sex/treatment group, and 150/sex/control group

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: 3 times a day

DETAILED CLINICAL OBSERVATIONS: Yes, for gross changes
- Time schedule: every 2 week

BODY WEIGHT: Yes
- Time schedule for examinations: animals were weighed every 2 weeks furing treatment, then every 8 weeks

HAEMATOLOGY: Not specified

CLINICAL CHEMISTRY: Not specified

Sacrifice and pathology:

Systematic and standardized histopathologic examinations were performed on each animal on the subcutaneous lymph nodes, brain and cerebellum, Zymbal glands, interscapular brown fat, salivary glands, Harderian glands, tongue, thymus and mediastinal lymph nodes, lungs, diaphragm, liver, kidneys, adrenals, spleen, mesenteric lymph nodes, stomach, various segments of the intestine, bladder, uterus, gonads, bone marrow smear, and any other organs with pathologic lesions.
Full necropsy was performed on all the animals.

Clinical signs:

no effects observed

Mortality:

mortality observed, non-treatment-related

Description (incidence):

There was no significant differences in survival linked to exposure to the test substance.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

There was no significant differences in body weight linked to exposure to the test substance.

Food consumption and compound intake (if feeding study):

not specified

Clinical biochemistry findings:

no effects observed

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

No non-neoplastics lesions were reported dor the list of organs examined

Histopathological findings: neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

The tumors most frequently expected in the rats of the strain used, on the basis of the literature and of the historical controls of the BT Experimental Unit, are mammary tumors (benign and malignant), leukemias, pheochromocytomas and pheochromoblastomas. Moreover, a variety of other miscellaneous tumors are also observed.

FC12: Rats (Exp. BT 601 + 601 bis):
Carcinogenicity; No noticeable differences, related to treatment, were found in the incidence of total benign and malignant, and malignant tumors, and of the most frequent expected or rare tumors.

Key result

Dose descriptor:

NOAEC

Effect level:

>= 5 000 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Critical effects observed:

no

Executive summary:

The propellant chlorofluorocarbon dichlorodifluoromethane (CFC-12) was administered for 104 weeks to rats by inhalation at a concentration of 5000, 1000 and 0 ppm, 4 hours daily, 5 days weekly.

The animals were kept under observation until spontaneous death.

No unexpected treatment-related tumors were observed in rats exposed to CFC-12. No important differences in the incidence of total benign and malignant tumors and of frequently occurring spontaneous tumors were observed in the rats exposed to CFC-12.

Under the experimental conditions, and on the basis of statistical analysis and of the oncological evaluation of the results, CFC-12 failed to show carcinogenic effects.

Reference 2

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1975

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Study with some limitations (e.g. only 1 dose included)

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: Rats (20/sex/group) were exposed daily (6 hrs/day, 7 days/week) to the test substance at 10000 ppm or control air for 90 days
- Parameters analysed / observed: behaviour, food consumption, body weight, as well as haematology, clinical biochemistry, urine parameters, macroscopic and microscopic examination

GLP compliance:

not specified

Limit test:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source of test material: Hoechst Aktiengesellschadt
- grade compliant with DIN 8960 refrigerant requirements

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: breeder S. Ivanovas, Kiblegg/Allgäu, FR, Germany
- Females (if applicable) nulliparous and non-pregnant: no data
- Age at study initiation: no data
- Weight at study initiation: 100 - 105 g
- Housing: Makrolon cages (type III)
- Diet : standard diet Altromin 1323, ad libitum
- Water: tap water ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.9 - 23.1 °C
- Humidity (%): 58.2 - 61.8% (maximum range)
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12hr light

IN-LIFE DATES: no data (study performed in 1975)

Route of administration:

inhalation: gas

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: chamber 3 m3 (3mx1mx1m)
- Source and rate of air: compressed air supply, cleaned
- Method of conditioning air: air cleaning with potassium dichromate-sulfuric acid, sodium hydroxide, glass wool and calcium hydroxide.
- Temperature, humidity, pressure in air chamber: 23.0°C (+/- 0.5°C), 60% relative humidity (+/- 3%)
- Air flow rate: controled (value not specified)
- Air change rate: no data
- Treatment of exhaust air: no data

TEST ATMOSPHERE
- Brief description of analytical method used: constant controls throughout the exposure period by gas chromatography, with immediate correction if the concentration differed by 3% from the nominal values.
- Samples taken from breathing zone: sampler and thermometer at the air/gas mixture entry, on the side wall of the exposure chamber, and at the air/gas mixture exit.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatography
Detection: WLD
carrier gas: helium
flow velocity: 950 ml/h
column: 5% OV 101 on gas chromium Q; 80-100 mesh
operating temperature: 30°C

Duration of treatment / exposure:

90 consecutive days

Frequency of treatment:

daily, 6 hours per day, 7 days per week

Dose / conc.:

0 ppm

Remarks:

control animals exposed to air flow without test gas

Dose / conc.:

10 000 ppm

Remarks:

Exposure concentration for rats

No. of animals per sex per dose:

20/sex/concentration

Control animals:

yes, concurrent vehicle

Details on study design:

No further details available

Positive control:

No

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Not specified

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

FOOD CONSUMPTION :
- Food consumption: assessed, but no further details provided

WATER CONSUMPTION : Yes, but no further details provided

OPHTHALMOSCOPIC EXAMINATION: Yes, no further details provided
- Time schedule for examinations: prior to sacrifice

HAEMATOLOGY: Yes
- Time schedule for collection of blood: no data
- Anaesthetic used for blood collection: Not specified
- Animals fasted: Not specified
- How many animals: No data
- Parameters examined: haemoglobin content, erythrocyte count, leucocyte count, differential count, reticulocyte count and platelet count, haematocrit value, methaemoglobin, blood clotting time and Heinz bodies;

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: no data
- Animals fasted: Not specified
- How many animals: No data
- Parameters examined: serum GPT, GOT, AP, glucose, BUN, total protein, bilirubin, lipids and cholesterol, sodium, potassium, calcium, chloride, uric acid, creatinine and protein fractions; liver function (BSP);

URINALYSIS: Yes
- Time schedule for collection of urine: not specified; after animals were administered 40 ml of 0.3% sodim chloride solution/kg bw, by gavage)
- Metabolism cages used for collection of urine: Not specified
- Animals fasted: Not specified
- Parameters examined:
* in urine: colour, specific gravity, protein, glucose, bilirubin, haemoglobin, ketone bodies, pH
* in sediment: epithelial cells, leucocytes, erythrocites, organsims, casts and crystalluria

NEUROBEHAVIOURAL EXAMINATION: sight and hearing were investigated (no further details)

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes, 27 organs were examined from 10 rats/sex/group

Statistics:

Analysis of variance and Student's t-test (p = 0.01)

Clinical signs:

no effects observed

Description (incidence and severity):

No effects on the behaviour and external appearance of rats.

Mortality:

no mortality observed

Description (incidence):

None of the animal died prematurely

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Description (incidence and severity):

No effect on composition of urine

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

No effects on sight, hearing or behaviour.

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

Occasional differences in individual organ weights can be regarded as incidental.

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Areas of focal alveolar over-inflation (not to be mistaken for emphysema) and an intraalveolar accumulation of macrophages were found to the same extent in the lungs of experimental and control rats. Isolated changes in other organs can be considered to be of spontaneous nature.

Key result

Dose descriptor:

NOAEC

Remarks:

Rats

Effect level:

>= 10 000 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

(test concentration eq. to 49500 mg/m3)

Key result

Critical effects observed:

no

Conclusions:

No adverse effects were reported in rats exposed to 10 000 ppm of dichlorodifluoromethane (eq. to 49500 mg/m3) for 90 consecutive days, 6 hour/day.

Executive summary:

A group of 40 Sprague-Dawley Rats (20 males and 20 females) were exposed daily (whole body, 6 hrs/day, 7 days/week) for 90 days to a concentration of 10000 ppm of Dichlorodifluoromethane. A concurrent group was exposed to air flow only.

Animals were examined for behaviour and external appearance, food consumption, water consumption, faeces, body weight. At the end of the exposure period, detailed examinations included analysis of haematologic parameters, clinical biochemistry parameters, urine, organ weights, macroscopic inspection and histopathology.

No mortality and no clinical signs were observed during the study. No effects were observed on food and water consumption, feaces, body weight, haematology, clinical biochemistry, and urine parameters. The autopsy did not show macroscopic findings.

Occasional variations in individual organ weights were considered incidental. Histopathological examination showed no noticeable changes attributed to treatment. Areas of focal alveolar over-inflation and accumulation of intraalveolar macrophages were found in lungs of both treated and control animals.

Under the conditions of the study the test concentration of 10000 ppm caused no adverse effects.

Reference 3

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: groups of animals were exposed to dichlorodifluoromethane daily for 30 exposures, or as a continuous exposure for 90 days.
- Short description of test conditions:
- Parameters analysed / observed:

GLP compliance:

no

Remarks:

Prior to GLP guidelines

Limit test:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Matheson Gas Company, East Rutherford, New Jersey

Species:

other: rats, guinea-pigs, monkeys, rabbits, dogs

Strain:

other: as stated in the publication: 15 Sprague-Dawley or Long-Evans, 15 Hartley guinea-pigs, 3 squirrel monkeys, 3 New-Zealand rabbits, 2 beagle dogs

Sex:

not specified

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation: no data
- Weight at study initiation: 192 g (range: 145-244g) at start of the repeated exposure study; 213 g (range: 165-262g) at the start of the continuous exposure study
- Housing:
- Diet : not specified
- Water : ad libitum
- Acclimation period:

DETAILS OF FOOD AND WATER QUALITY: commercial dry chow.

ENVIRONMENTAL CONDITIONS : (exposure chambers)
- Temperature (°C): 75 to 80°F (23 to 26.7°C)
- Humidity (%): 50%
- Air changes (per hr): 1.23 m3/ minute
- Photoperiod (hrs dark / hrs light): no data

IN-LIFE DATES: no data

Route of administration:

inhalation: gas

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: chamber (no details)
- Source and rate of air: no data
- Method of conditioning air: a stream of pure gaseous dichlorodifluoromethane from a high-pressure cylinder was metered through a rotameter into a mixing bottle and carried into the chember where it was diluted to the atrget concentration with air.
- Temperature, humidity, pressure in air chamber: 75-80°F (23.6-26.6 °C), 50% humidity, negative pressure at 2.0 inches if water
- Air flow rate: 1.25 m3/minute
- Air change rate: no data
- Treatment of exhaust air: no data

TEST ATMOSPHERE
- Brief description of analytical method used: continous monitoring of chamber concentrations by infrared analysis.
- Samples taken from breathing zone: no data

VEHICLE (if applicable)
- Justification for use and choice of vehicle: no data
- Composition of vehicle: air

Analytical verification of doses or concentrations:

yes

Remarks:

Infrared analysis

Details on analytical verification of doses or concentrations:

Infrared analysis. A stream of chamber air was drawn through a variable pathlength gas cell fitted to an infrared spectrophotometer. The instrument was locked on the analytical wavelength selected for the contaminant and the percent transmission was continuously recorded. The contaminant level was then read from a graph of concentration vs percent transmission previously prepared by vaporizing known amounts of the test material in the gas cell.
Chemical analysis were performed daily and correlated with nominal input data.

Duration of treatment / exposure:

- repeated exposure study: 30 exposures
- continuous exposure study: 90 days

Frequency of treatment:

- Repeated exposures: Daily 8 hours/day, 5 days/week for a total of 30 exposures
- Continuous exposure for 90-day, except for feeding the animals and servicing the chambers (< 2% of the total chamber time)

Dose / conc.:

0 mg/m³ air

Dose / conc.:

4 136 mg/m³ air

Remarks:

30 repeated exposures (Mean +/- SD 87)

Dose / conc.:

3 997 mg/m³ air

Remarks:

90-day continuous exposure (Mean +/- SD 113)

No. of animals per sex per dose:

15 rats per dose (sex not specified)

Control animals:

yes, concurrent no treatment

Positive control:

no

Observations and examinations performed and frequency:

DETAILED CLINICAL OBSERVATIONS: yes
All animals were routinely examined for signs of toxicity, marked alterations in behaviour, physical appearance, respiration pattern, locomotor activity and prostration.

BODY WEIGHT: Yes
- Time schedule for examinations: prior to exposure, at monthly intervals and at the termination of the study.

HAEMATOLOGY: Yes
- Time schedule for collection of blood: no data
- Anaesthetic used for blood collection: Not specified
- Animals fasted: Not specified
- How many animals: Not specified
- Parameters examined : Total and differential Leukocyte counts, Hemoglobin concentration, Hematocrit, before and after the exposure

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:
- Animals fasted: Yes / No / Not specified
- How many animals:
- Parameters examined:
* Reduced nicotinamide adenine dinucleotide (NADH), reduced nicotinamide adenine dinucleotide phosphate ( NADPH), activities of succinic dehydrogenase ( SDH ), lactic dehydrogenase ( LDH), isocitric dehydrogenase ( ICD), glucose-6-phosphate dehydrogenase ( GGPD), and p-hydroxybutyric dehydrogenase (B-OHBD).
* Alkaline phosphatase activity
* Serum glutamic-pyruvic transaminase levels
* Serum urea nitrogen concentrations
* Liver lipids

URINALYSIS: Not specified

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes : heart, lung, liver, spleen, kidney

Clinical signs:

no effects observed

Description (incidence and severity):

Repeated exposure: No signs of toxicity were observed in the rat survivors.
Continuous exposure: no visible signs of toxicity

Mortality:

mortality observed, treatment-related

Description (incidence):

Rats: (no details on day)
1/15 in the repeated exposure group
2/15 in the continuous exposure group
7/304 controls

Guinea-pigs:
1/15 in the continuous exposure group.

No mortality observed in the other groups and species.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

* Repeated exposure: no effect reported
* continuous exposure: No effects reported in rats. Body weights of the rabbits and guinea-pigs were depressed.

Food consumption and compound intake (if feeding study):

not examined

Ophthalmological findings:

not examined

Clinical biochemistry findings:

not specified

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

No details

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

* Repeated exposure: several rats and guinea pigs, had varying degrees of lung congestion.
Other organs appeared normal.
No effects were reported in rats, but guinea-pigs showed focal necrosis of the liver, but which could not be defintely attributed to the exposure.

* Continuous exposure: high incidence of varying degrees of lung congestion in rats, rabbits, monkeys, guinea-pigs.
In guinea-pigs, submassive necrosis of the liver was noted in the surviving guinea-pigs.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

* Repeated exposure: non-specific interstitial inflammatory changes in the lungs of both treated and control animals.
- Several guinea-pigs showed focal necrosis or fatty infiltration of the liver.
- one monkey had heavy pigment deposits in the liver, spleen, kidney.

* Continuous exposure: non-specific interstitial inflammatory changes in the lungs (all species)
- one guinea-pig showed a focal giant cell pneumonitis. All guinea-pig liver sections: slight to extensive fatty infliltration of the hepatic cells; several sections with focal or submassive necrosis of the liver. It could not be determined if this toxic response was due to the continuous exposure or to the higher susceptibility of the guinea-pigs, already noted in other studies.

Histopathological findings: neoplastic:

not specified

Key result

Dose descriptor:

NOAEC

Effect level:

ca. 3 997 mg/m³ air (nominal)

Based on:

test mat.

Sex:

not specified

Key result

Critical effects observed:

no

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

24 676 mg/m³

Study duration:

chronic

Species:

rat

Repeated dose toxicity: inhalation - local effects

Link to relevant study records

Reference

Reference 1

Endpoint:

chronic toxicity: inhalation

Remarks:

(carcinogenicity)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1975 to 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Reason / purpose for cross-reference:

reference to same study

Remarks:

carcinogenicity study

Qualifier:

no guideline followed

Principles of method if other than guideline:

CFC-12 was tested by inhalation on Sprague-Dawley rats and Swiss Mice using whole body exposure. The animals were exposed by inhalation, 4 hours daily, 5 days weekly, for 104 weeks (rats: Exp. BT 601, 601 bis) and 78 weeks (mice: Exp. BT 602).
All the animals were kept under control until spontaneous death. The status and behaviour of the animals were controlled three times daily. The animals were submitted to clinical examination for gross changes every 2 weeks. The animals were weighed every 2 weeks during treatment, and then every 8 weeks. Full necropsy was performed on all the animals. The housing and the diet of the animals were the same highly standardized ones adopted in the BT Experimental Unit during the last 15 years before the beginning of this experiment.

GLP compliance:

not specified

Limit test:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source of test material: Montedison, Italy
- Purity : 99.98%

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

inhalation: gas

Type of inhalation exposure:

whole body

Vehicle:

air

Dose / conc.:

0 ppm (nominal)

Dose / conc.:

1 000 ppm (nominal)

Remarks:

eq. to 4945 mg/m3

Dose / conc.:

5 000 ppm (nominal)

Remarks:

eq. to 24676 mg/m3

No. of animals per sex per dose:

660 total (330 male & 330 female rats): 90/sex/treatment group, and 150/sex/control group

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: 3 times a day

DETAILED CLINICAL OBSERVATIONS: Yes, for gross changes
- Time schedule: every 2 week

BODY WEIGHT: Yes
- Time schedule for examinations: animals were weighed every 2 weeks furing treatment, then every 8 weeks

HAEMATOLOGY: Not specified

CLINICAL CHEMISTRY: Not specified

Sacrifice and pathology:

Systematic and standardized histopathologic examinations were performed on each animal on the subcutaneous lymph nodes, brain and cerebellum, Zymbal glands, interscapular brown fat, salivary glands, Harderian glands, tongue, thymus and mediastinal lymph nodes, lungs, diaphragm, liver, kidneys, adrenals, spleen, mesenteric lymph nodes, stomach, various segments of the intestine, bladder, uterus, gonads, bone marrow smear, and any other organs with pathologic lesions.
Full necropsy was performed on all the animals.

Clinical signs:

no effects observed

Mortality:

mortality observed, non-treatment-related

Description (incidence):

There was no significant differences in survival linked to exposure to the test substance.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

There was no significant differences in body weight linked to exposure to the test substance.

Food consumption and compound intake (if feeding study):

not specified

Clinical biochemistry findings:

no effects observed

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

No non-neoplastics lesions were reported dor the list of organs examined

Histopathological findings: neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

The tumors most frequently expected in the rats of the strain used, on the basis of the literature and of the historical controls of the BT Experimental Unit, are mammary tumors (benign and malignant), leukemias, pheochromocytomas and pheochromoblastomas. Moreover, a variety of other miscellaneous tumors are also observed.

FC12: Rats (Exp. BT 601 + 601 bis):
Carcinogenicity; No noticeable differences, related to treatment, were found in the incidence of total benign and malignant, and malignant tumors, and of the most frequent expected or rare tumors.

Key result

Dose descriptor:

NOAEC

Effect level:

>= 5 000 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Critical effects observed:

no

Executive summary:

The propellant chlorofluorocarbon dichlorodifluoromethane (CFC-12) was administered for 104 weeks to rats by inhalation at a concentration of 5000, 1000 and 0 ppm, 4 hours daily, 5 days weekly.

The animals were kept under observation until spontaneous death.

No unexpected treatment-related tumors were observed in rats exposed to CFC-12. No important differences in the incidence of total benign and malignant tumors and of frequently occurring spontaneous tumors were observed in the rats exposed to CFC-12.

Under the experimental conditions, and on the basis of statistical analysis and of the oncological evaluation of the results, CFC-12 failed to show carcinogenic effects.

Reference 2

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1975

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Study with some limitations (e.g. only 1 dose included)

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: Rats (20/sex/group) were exposed daily (6 hrs/day, 7 days/week) to the test substance at 10000 ppm or control air for 90 days
- Parameters analysed / observed: behaviour, food consumption, body weight, as well as haematology, clinical biochemistry, urine parameters, macroscopic and microscopic examination

GLP compliance:

not specified

Limit test:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source of test material: Hoechst Aktiengesellschadt
- grade compliant with DIN 8960 refrigerant requirements

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: breeder S. Ivanovas, Kiblegg/Allgäu, FR, Germany
- Females (if applicable) nulliparous and non-pregnant: no data
- Age at study initiation: no data
- Weight at study initiation: 100 - 105 g
- Housing: Makrolon cages (type III)
- Diet : standard diet Altromin 1323, ad libitum
- Water: tap water ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.9 - 23.1 °C
- Humidity (%): 58.2 - 61.8% (maximum range)
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12hr light

IN-LIFE DATES: no data (study performed in 1975)

Route of administration:

inhalation: gas

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: chamber 3 m3 (3mx1mx1m)
- Source and rate of air: compressed air supply, cleaned
- Method of conditioning air: air cleaning with potassium dichromate-sulfuric acid, sodium hydroxide, glass wool and calcium hydroxide.
- Temperature, humidity, pressure in air chamber: 23.0°C (+/- 0.5°C), 60% relative humidity (+/- 3%)
- Air flow rate: controled (value not specified)
- Air change rate: no data
- Treatment of exhaust air: no data

TEST ATMOSPHERE
- Brief description of analytical method used: constant controls throughout the exposure period by gas chromatography, with immediate correction if the concentration differed by 3% from the nominal values.
- Samples taken from breathing zone: sampler and thermometer at the air/gas mixture entry, on the side wall of the exposure chamber, and at the air/gas mixture exit.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatography
Detection: WLD
carrier gas: helium
flow velocity: 950 ml/h
column: 5% OV 101 on gas chromium Q; 80-100 mesh
operating temperature: 30°C

Duration of treatment / exposure:

90 consecutive days

Frequency of treatment:

daily, 6 hours per day, 7 days per week

Dose / conc.:

0 ppm

Remarks:

control animals exposed to air flow without test gas

Dose / conc.:

10 000 ppm

Remarks:

Exposure concentration for rats

No. of animals per sex per dose:

20/sex/concentration

Control animals:

yes, concurrent vehicle

Details on study design:

No further details available

Positive control:

No

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Not specified

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

FOOD CONSUMPTION :
- Food consumption: assessed, but no further details provided

WATER CONSUMPTION : Yes, but no further details provided

OPHTHALMOSCOPIC EXAMINATION: Yes, no further details provided
- Time schedule for examinations: prior to sacrifice

HAEMATOLOGY: Yes
- Time schedule for collection of blood: no data
- Anaesthetic used for blood collection: Not specified
- Animals fasted: Not specified
- How many animals: No data
- Parameters examined: haemoglobin content, erythrocyte count, leucocyte count, differential count, reticulocyte count and platelet count, haematocrit value, methaemoglobin, blood clotting time and Heinz bodies;

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: no data
- Animals fasted: Not specified
- How many animals: No data
- Parameters examined: serum GPT, GOT, AP, glucose, BUN, total protein, bilirubin, lipids and cholesterol, sodium, potassium, calcium, chloride, uric acid, creatinine and protein fractions; liver function (BSP);

URINALYSIS: Yes
- Time schedule for collection of urine: not specified; after animals were administered 40 ml of 0.3% sodim chloride solution/kg bw, by gavage)
- Metabolism cages used for collection of urine: Not specified
- Animals fasted: Not specified
- Parameters examined:
* in urine: colour, specific gravity, protein, glucose, bilirubin, haemoglobin, ketone bodies, pH
* in sediment: epithelial cells, leucocytes, erythrocites, organsims, casts and crystalluria

NEUROBEHAVIOURAL EXAMINATION: sight and hearing were investigated (no further details)

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes, 27 organs were examined from 10 rats/sex/group

Statistics:

Analysis of variance and Student's t-test (p = 0.01)

Clinical signs:

no effects observed

Description (incidence and severity):

No effects on the behaviour and external appearance of rats.

Mortality:

no mortality observed

Description (incidence):

None of the animal died prematurely

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Description (incidence and severity):

No effect on composition of urine

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

No effects on sight, hearing or behaviour.

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

Occasional differences in individual organ weights can be regarded as incidental.

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Areas of focal alveolar over-inflation (not to be mistaken for emphysema) and an intraalveolar accumulation of macrophages were found to the same extent in the lungs of experimental and control rats. Isolated changes in other organs can be considered to be of spontaneous nature.

Key result

Dose descriptor:

NOAEC

Remarks:

Rats

Effect level:

>= 10 000 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

(test concentration eq. to 49500 mg/m3)

Key result

Critical effects observed:

no

Conclusions:

No adverse effects were reported in rats exposed to 10 000 ppm of dichlorodifluoromethane (eq. to 49500 mg/m3) for 90 consecutive days, 6 hour/day.

Executive summary:

A group of 40 Sprague-Dawley Rats (20 males and 20 females) were exposed daily (whole body, 6 hrs/day, 7 days/week) for 90 days to a concentration of 10000 ppm of Dichlorodifluoromethane. A concurrent group was exposed to air flow only.

Animals were examined for behaviour and external appearance, food consumption, water consumption, faeces, body weight. At the end of the exposure period, detailed examinations included analysis of haematologic parameters, clinical biochemistry parameters, urine, organ weights, macroscopic inspection and histopathology.

No mortality and no clinical signs were observed during the study. No effects were observed on food and water consumption, feaces, body weight, haematology, clinical biochemistry, and urine parameters. The autopsy did not show macroscopic findings.

Occasional variations in individual organ weights were considered incidental. Histopathological examination showed no noticeable changes attributed to treatment. Areas of focal alveolar over-inflation and accumulation of intraalveolar macrophages were found in lungs of both treated and control animals.

Under the conditions of the study the test concentration of 10000 ppm caused no adverse effects.

Reference 3

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: groups of animals were exposed to dichlorodifluoromethane daily for 30 exposures, or as a continuous exposure for 90 days.
- Short description of test conditions:
- Parameters analysed / observed:

GLP compliance:

no

Remarks:

Prior to GLP guidelines

Limit test:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Matheson Gas Company, East Rutherford, New Jersey

Species:

other: rats, guinea-pigs, monkeys, rabbits, dogs

Strain:

other: as stated in the publication: 15 Sprague-Dawley or Long-Evans, 15 Hartley guinea-pigs, 3 squirrel monkeys, 3 New-Zealand rabbits, 2 beagle dogs

Sex:

not specified

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation: no data
- Weight at study initiation: 192 g (range: 145-244g) at start of the repeated exposure study; 213 g (range: 165-262g) at the start of the continuous exposure study
- Housing:
- Diet : not specified
- Water : ad libitum
- Acclimation period:

DETAILS OF FOOD AND WATER QUALITY: commercial dry chow.

ENVIRONMENTAL CONDITIONS : (exposure chambers)
- Temperature (°C): 75 to 80°F (23 to 26.7°C)
- Humidity (%): 50%
- Air changes (per hr): 1.23 m3/ minute
- Photoperiod (hrs dark / hrs light): no data

IN-LIFE DATES: no data

Route of administration:

inhalation: gas

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: chamber (no details)
- Source and rate of air: no data
- Method of conditioning air: a stream of pure gaseous dichlorodifluoromethane from a high-pressure cylinder was metered through a rotameter into a mixing bottle and carried into the chember where it was diluted to the atrget concentration with air.
- Temperature, humidity, pressure in air chamber: 75-80°F (23.6-26.6 °C), 50% humidity, negative pressure at 2.0 inches if water
- Air flow rate: 1.25 m3/minute
- Air change rate: no data
- Treatment of exhaust air: no data

TEST ATMOSPHERE
- Brief description of analytical method used: continous monitoring of chamber concentrations by infrared analysis.
- Samples taken from breathing zone: no data

VEHICLE (if applicable)
- Justification for use and choice of vehicle: no data
- Composition of vehicle: air

Analytical verification of doses or concentrations:

yes

Remarks:

Infrared analysis

Details on analytical verification of doses or concentrations:

Infrared analysis. A stream of chamber air was drawn through a variable pathlength gas cell fitted to an infrared spectrophotometer. The instrument was locked on the analytical wavelength selected for the contaminant and the percent transmission was continuously recorded. The contaminant level was then read from a graph of concentration vs percent transmission previously prepared by vaporizing known amounts of the test material in the gas cell.
Chemical analysis were performed daily and correlated with nominal input data.

Duration of treatment / exposure:

- repeated exposure study: 30 exposures
- continuous exposure study: 90 days

Frequency of treatment:

- Repeated exposures: Daily 8 hours/day, 5 days/week for a total of 30 exposures
- Continuous exposure for 90-day, except for feeding the animals and servicing the chambers (< 2% of the total chamber time)

Dose / conc.:

0 mg/m³ air

Dose / conc.:

4 136 mg/m³ air

Remarks:

30 repeated exposures (Mean +/- SD 87)

Dose / conc.:

3 997 mg/m³ air

Remarks:

90-day continuous exposure (Mean +/- SD 113)

No. of animals per sex per dose:

15 rats per dose (sex not specified)

Control animals:

yes, concurrent no treatment

Positive control:

no

Observations and examinations performed and frequency:

DETAILED CLINICAL OBSERVATIONS: yes
All animals were routinely examined for signs of toxicity, marked alterations in behaviour, physical appearance, respiration pattern, locomotor activity and prostration.

BODY WEIGHT: Yes
- Time schedule for examinations: prior to exposure, at monthly intervals and at the termination of the study.

HAEMATOLOGY: Yes
- Time schedule for collection of blood: no data
- Anaesthetic used for blood collection: Not specified
- Animals fasted: Not specified
- How many animals: Not specified
- Parameters examined : Total and differential Leukocyte counts, Hemoglobin concentration, Hematocrit, before and after the exposure

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:
- Animals fasted: Yes / No / Not specified
- How many animals:
- Parameters examined:
* Reduced nicotinamide adenine dinucleotide (NADH), reduced nicotinamide adenine dinucleotide phosphate ( NADPH), activities of succinic dehydrogenase ( SDH ), lactic dehydrogenase ( LDH), isocitric dehydrogenase ( ICD), glucose-6-phosphate dehydrogenase ( GGPD), and p-hydroxybutyric dehydrogenase (B-OHBD).
* Alkaline phosphatase activity
* Serum glutamic-pyruvic transaminase levels
* Serum urea nitrogen concentrations
* Liver lipids

URINALYSIS: Not specified

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes : heart, lung, liver, spleen, kidney

Clinical signs:

no effects observed

Description (incidence and severity):

Repeated exposure: No signs of toxicity were observed in the rat survivors.
Continuous exposure: no visible signs of toxicity

Mortality:

mortality observed, treatment-related

Description (incidence):

Rats: (no details on day)
1/15 in the repeated exposure group
2/15 in the continuous exposure group
7/304 controls

Guinea-pigs:
1/15 in the continuous exposure group.

No mortality observed in the other groups and species.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

* Repeated exposure: no effect reported
* continuous exposure: No effects reported in rats. Body weights of the rabbits and guinea-pigs were depressed.

Food consumption and compound intake (if feeding study):

not examined

Ophthalmological findings:

not examined

Clinical biochemistry findings:

not specified

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

No details

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

* Repeated exposure: several rats and guinea pigs, had varying degrees of lung congestion.
Other organs appeared normal.
No effects were reported in rats, but guinea-pigs showed focal necrosis of the liver, but which could not be defintely attributed to the exposure.

* Continuous exposure: high incidence of varying degrees of lung congestion in rats, rabbits, monkeys, guinea-pigs.
In guinea-pigs, submassive necrosis of the liver was noted in the surviving guinea-pigs.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

* Repeated exposure: non-specific interstitial inflammatory changes in the lungs of both treated and control animals.
- Several guinea-pigs showed focal necrosis or fatty infiltration of the liver.
- one monkey had heavy pigment deposits in the liver, spleen, kidney.

* Continuous exposure: non-specific interstitial inflammatory changes in the lungs (all species)
- one guinea-pig showed a focal giant cell pneumonitis. All guinea-pig liver sections: slight to extensive fatty infliltration of the hepatic cells; several sections with focal or submassive necrosis of the liver. It could not be determined if this toxic response was due to the continuous exposure or to the higher susceptibility of the guinea-pigs, already noted in other studies.

Histopathological findings: neoplastic:

not specified

Key result

Dose descriptor:

NOAEC

Effect level:

ca. 3 997 mg/m³ air (nominal)

Based on:

test mat.

Sex:

not specified

Key result

Critical effects observed:

no

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

chronic toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In accordance with section 2 REACH Annex XI, studies via the oral and dermal route do not need to be conducted as the substance is a gas.

The toxicity of CFC-12 following repeated exposure by inhalation has been studied in the mouse and dog. In long-term inhalation toxicity studies by Smith & Case (1973), mice and dogs were exposed regularly for brief periods to high levels of mixtures containing CFC-12, at 49% and 50%, respectively. In this study 30 female mice were exposed by inhalation 5 days/week at levels of 0 or 970 mg/kg (calculated value) per day for 23 months. No signs of toxicity were observed during the study and there was no evidence of lung tumours after the 23 months of exposure. When adult dogs (three of each sex) were exposed 7 days/week at levels of 0 or 2240 mg/kg (calculated value) per day for 1 year, some signs of toxicity, such as slight depression or drowsiness, were observed in dogs immediately after dosing but lasted only a few minutes. Tissue sections of the lungs did not show signs of toxicity or irritation from inhalation. Also, no changes were observed in haematology, blood chemistry, or urinalysis.

On the basis of the dose levels noted in approximately 50% CFC-12 dose levels, no classification is required.

In addition, dogs, monkeys and guinea pigs were exposed to air containing 20 per cent by volume of dichlorodifluoromethane vapour for 7 to 8 hours daily on five days, and for four hours on the sixth day of each week during a 12-week period. During the exposure they were observed for unnatural signs or symptoms; change in weight; changes in red blood cells, hemoglobin, and white blood cells and their types; fatality and pathology indicative of deleterious action of the gas.

1. Exposure for 7 to 8 hours daily to 20 per cent dichlorodifluoro methane produces mild to moderate to marked generalised tremor in dogs and mild to moderate generalised tremor in monkeys. When they attempt to walk, they act very much like persons suffering from alcoholic ataxia. They react to light and stimuli and do not become unconscious. The maximum severity of symptoms is reached in the first 10 to 20 minutes of an exposure. A tolerance is developed with successive exposures as manifested by decrease in severity of the symptoms. Guinea pigs exhibit no significant symptoms.      

2. During the first two or three weeks of the test the weight and growth of some of the animals were slightly to moderately inhibited, but during the succeeding two to three weeks they regained and loss and thereafter maintained weight and growth similar to unexposed control animals.      

3. The number of red blood cells and hemoglobin tended toward a slight increase during the first two to three weeks of the test but thereafter was normal and similar to control animals; also, the number of white cells was the same as the controls. Differential white cell examinations showed a slight increase in the polymorphonuclear neutrophils and a slight decrease in lymphocytes in the blood of animals exposed to dichlorodifluoro methane. The number of eosinophils, basophils, lymphoblasts, endothelial cells, normoblasts, and Kurloff bodies was practically the same for both the animals exposed to dichloro-difluoro methane and the controls.      

4. No fatalities occurred among the dogs and monkeys. The fatality among the guinea pigs used for symptoms, weight, and fatality observations was two out of a group of 16 exposed to gas and one out of a group of 16 controls during the 12 -week test period, thus indicating no effects of exposure on fatality.      

5. Autopsies performed on all animals revealed no gross pathology attributable to the exposure to dichloro-difluoro methane.      

6. Pregnancy and bearing normal young were frequent among the guinea pigs exposed to dichloro-difluoro methane as among the controls. No abortions or abnormal foeti were observed.      

7. In so far as the results of animal experimentation serve as a measure of hazards to persons, the investigations described in this report has shown that the possibility of public health and accident hazards resulting from exposure to dichloro-difluoro methane when used as a refrigerant are remote.      

 

In addition, a carcinogenicity study on the substance was conducted. Three propellant chlorofluorocarbons, namely trichlorofluoromethane (FC11), dichlorodifluoromethane (FC 12), and chlorodifluoromethane (FC22) were administered by inhalation at a concentration of 5000, 1000 and 0 ppm, 4 hours daily, 5 days weekly, for 104 and 78 weeks, to rats and mice, respectively.

As a result of this study, no unexpected treatment-related tumors were observed in rats exposed to FC11, FC12, and FC22. No important differences in the incidence of total benign and malignant tumors and of frequently occurring spontaneous tumors were observed in the rats exposed to the tested propellants. The incidence of all tumors and of some particular frequently occurring spontaneous tumors in mice showed a tendency to increase in animals exposed to FC11 and FC12.The increased incidence was usually observed in one sex and was not always dose-related, possibly due to a longer survival of the treated mice compared with controls.

 

Under the experimental conditions, and on the basis of statistical analysis and of the oncological evaluation of the results, FC11, FC12 and FC22 failed to show carcinogenic effects.

 

Value used for CSA (route: inhalation):

NOEC 24676 mg/m3 air (5000 ppm from the 2-year carcinogenicity study in the rat)

This is a lowest NO(A)EC used a point of departure for the DNEL derivation, compared to using the 90-day inhalation study NOAEC of 49350 mg/m3 (10000 ppm).

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
This route of exposure is not applicable to the substance as a gas. One existing study by oral gavage did not show adverse effect after 2 years of administration to rats.

Justification for selection of repeated dose toxicity inhalation - local effects endpoint:
Not assessed. Local effects were not documented in the repeated dose study data available, and no further studies are deemed appropriate.

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint:
This route of exposure is not applicable to the substance as a gas.

Justification for selection of repeated dose toxicity dermal - local effects endpoint:
This route of exposure is not applicable to the substance as a gas.

Justification for classification or non-classification

There are several repeated dose toxicity studies available investigating potential CFC-12 effects. Although they were not conducted according to GLP and are not in compliance with current standardised protocols, they are considered appropriate for assessment purposes in accordance with the criteria listed in Annex XI. 90-day repeated dose toxicity studies in rats and dogs, and chronic studies in rats and mice provided no evidence of serious adverse effects following inhalation exposure, or via oral administration in feed.

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