Formamide

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study.

Data source

Reference

Reference Type:

other: TSCATS

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes

Test type:

standard acute method

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; purity >99%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure:

not specified

Vehicle:

other: no vehicle

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus:
- Exposure chamber volume:
- Method of holding animals in test chamber:
- Source and rate of air:
- Method of conditioning air:
- System of generating particulates/aerosols: two different methods were used: 1) a nebulizer and 2) an evaporator heated to approx. 100-210°C. - - Method of particle size determination:
- Treatment of exhaust air:
- Temperature, humidity, pressure in air chamber:


TEST ATMOSPHERE
- Brief description of analytical method used:  two different methods were use: 1) GD/FID and 2) gravimetric analysis.




TEST ATMOSPHERE
- Particle size distribution: tabulated below
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): tabulated below

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

1.3, 2.0, 5.1, 14, 19, 21 mg/l (mean concentrations)

No. of animals per sex per dose:

6

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes/no
- Other examinations performed: clinical signs, body weight

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LC50

Effect level:

> 21 mg/L air

Exp. duration:

4 h

Mortality:

One of the rats exposed to 21 mg/l died 11 days after exposure. No deaths were observed at the other test concentrations. The LC50 was >21 mg/l in this study.

Clinical signs:

other: No clinical signs were noted during exposure. Immediately thereafter, rats from all groups exhibited ocular and nasal discharges, and the rats of the  two high dose groups had compound-covered faces.  Clinical signs included lethargy, hunched posture, cle

Body weight:

Body weight losses were seen in rats from the 14, 19, and 21 mg/l groups for up to 5 days post exposure. One rat of the 21 mg/l group continued to loose weight and was found dead 11 days post exposure. 

Applicant's summary and conclusion

Executive summary:

Conclusion

 

In an inhalation study that was conducted similar to OECD TG No. 403 and under GLP, 6 male Sprague-Dawley rats were exposed for 4 hours to mean analytical concentrations of 1.3, 2.0, 5.1, 14, 19, 21 mg/L. The test atmosphere was generated by metering the test material into a round-bottom flask heated to 100-210 deg C for concentrations less than 19 mg/L. The two highest atmospheric concentrations were generated with a nebulizer. Within the 14 day observation period mortality was

observed in 1 animal in the 21 mg/L dose group. Clinical observations included lethargy, hunched posture, ocular and nasal discharges, partially-closed eyes, diarrhea, brown-stained perineum, and weight loss. Gross necropsy was not reported. The LC₅₀is considered to be > 21 mg/L (TSCATS, 1987).