N-methylformamide

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: see 'Remark'

Remarks:

Comparable to Guideline study with acceptable restrictions (partly limited documentation, e.g. no further details on the test substance or onset of clinical symptoms; max technical feasible concentration used [limit concentration according to OECD 403 is 5 mg/l; minor restriction]).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

monomethylformamide

IUPAC Name:

monomethylformamide

Details on test material:

Purity: 99.7%
no further details

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Source: Firma WIGA, Sulzfeld,
Initial body weight: 200 +- 30g
After exposure certified diet and tap water ad libitum
no further details

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose/head only

Vehicle:

other: air

Details on inhalation exposure:

Aerosol generation:
Constant supply of the liquid test substance to a nozzle via an infusion pump and generation of aerosol via compressed air (2.5 bar) which was fed to the nozzle. Inhalation system fed with the aerosol (slight over-pressure of 1 Pa).
Samples (3 l/minutes, total volume 5 l; near the head of animals) analysed by GC methods. Data of 4 samples were given (mean value in the result section)

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Nominal 24.1 mg/l
Analytical value (mean): 4.1 mg/l

No. of animals per sex per dose:

10

Control animals:

other: not required

Details on study design:

Post exposure observation period 14 days
Clinical symptoms recorded daily
Body weight measured day 0, 7, 14
Necropsy performed

Statistics:

not required

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 4.1 mg/L air

Exp. duration:

4 h

Mortality:

0/10 females and 0/10 males

Clinical signs:

other: watery or bloody secretion from the nose increased respiration rate ruffled coat prone position all effects reversible within 6 days

Body weight:

clearly reduced body weight gain in males, slight reduction in females

Gross pathology:

no effects

Other findings:

no

Applicant's summary and conclusion

Conclusions:

The LC50 (4 h) in male and female Sprague-Dawley rats is > 4.1 mg/l (1670 ppm).

Executive summary:

omparable to Guideline study with acceptable restrictions (partly limited documentation, e.g. no further details on the test substance or onset of clinical symptoms; max technical feasible concentration used [limit concentration according to OECD 403 is 5 mg/l; minor restriction]).

Ten female and 10 male Sprague-Dawley rats were exposed to an aerosol for 4 h (head only exposure), the analytical concentration was 4.1 mg/l (nominal 24.1 mg/l). Body weight was measured at day 0, 7, and 14. The clinical symptoms were recorded daily. After the post exposure period of 14 days the rats were necropsied.

No mortality was found. Authors reported watery or bloody secretion from the nose, increased respiration rate, ruffled coat, and prone position. All effects were reversible within 6 days. Clearly reduced body weight gain was seen in males, slight reduction in females. No effects were detected at necropsy.

Conclusion: The LC50 (4 h) in male and female Sprague-Dawley rats is > 4.1 mg/l (1670 ppm).