Formamide

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Restrictions: concentrations were not measured. Observation period was not reported. Heating to 150°C may have generated breakdown products; this second experiment is not similar to OECD TG 403.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1963

Report date:

1963

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

; test substance was heated in a second experiment

Principles of method if other than guideline:

Inhalation hazard test

GLP compliance:

no

Test type:

other: Inhalation hazard test

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Formamide

EC Number:

200-842-0

EC Name:

Formamide

Cas Number:

75-12-7

Molecular formula:

CH3NO

IUPAC Name:

formamide

Details on test material:

Formamide, degree of purity not reported.

Test animals

Species:

rat

Strain:

not specified

Sex:

not specified

Details on test animals or test system and environmental conditions:

no data

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

not specified

Vehicle:

other: air

Details on inhalation exposure:

- Exposure: animals were exposed to vapors of TS
- Atmosphere generation: air was conducted through a 5 cm-layer of TS in a wash-bottle at room temperature (20°C).
In a second experiment TS was also heated to 150°C in order to produce vapors.
- Observation period: no data.
- Measurement: not performed.

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

8 h

Concentrations:

near saturation

No. of animals per sex per dose:

12

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: not specified

Results and discussion

Effect levels

Key result

Sex:

not specified

Dose descriptor:

LC0

Effect level:

>

Based on:

test mat.

Exp. duration:

8 h

Remarks on result:

not determinable because of methodological limitations

Remarks:

No effects were observed at the vapour saturation concentration.

Mortality:

1st experiment: No mortality was observed when 12 rats were exposed for 8 hours to an atmosphere that had been saturated with the volatile parts of formamide at 20 °C. No clinical signs of toxicity were observed. No gross pathological findings were seen.
2nd experiment: One out of 12 rats died after an 8-hour exposure to an atmosphere that had been saturated with the volatile parts of formamide at 150 °C. 

Clinical signs:

other: 1st experiment: No clinical signs of toxicity were observed in 12 rats, exposed for 8 hours to an atmosphere that had been saturated with the volatile parts of formamide at 20 °C. 2nd experiment (formamide heated to 150°C): Clinical signs of toxicity incl

Gross pathology:

1st experiment: No gross pathological findings were seen in 12 rats, exposed for 8 hours to an atmosphere that had been saturated with the volatile parts of formamide at 20 °C.
2nd experiment (formamide heated to 150°C):  No gross pathological findings were seen except for slight pneumonia in two animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The lethal inhalation concentration is above the saturated air concentration.

Executive summary:

In a pre-guideline In halation Hazard Test performed similar to OECD TG 403, 12 rats were exposed for 8 hours to formamide vapours near saturation. The concentration was not analytically determined. There were no mortalities, clinical signs of toxicity, or findings during necropsy. Thus there was no indication of an inhalation risk due to vapors of formamide at concentrations near saturation at 20°C. In a second experiment the atmosphere generation included heating formamide to 150°C. This may have generated breakdown products, and this experiment is not considered to be similar to OECD TG 403. One animal of 12 died, clinical signs included irritation of mucous membranes, dyspnea lasting for days, apathy, and loss of weight, but there were no pathological changes noted at termination that was related to the test substance. It is likely that the animals were exposed to a mixture of vapours and aerosols in the second experiment (BASF, 1963).