Butyl isocyanate

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: guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Principles of method if other than guideline:

ADMINISTRATION: vapor inhalation under dynamic head-nose only exposure conditions post observation period: approx. 4 weeks nominal concentrations: 13; 21; 54; 83; 108; 187; 399; 1077 mg/m³ analytical concentrations: 3.1; 7.2; 31.7; 55.6; 63.6; 109.8; 270.3; 861.9 mg/m³ EXAMINATIONS: mortality; clinical signs; body weight; rectal temperature,reflex, necropsy

GLP compliance:

yes

Test type:

standard acute method

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

n-butyl isocyanate, purity: 99.5 %

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose/head only

Vehicle:

other: unchanged (no vehicle)

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

3, 7, 32, 56, 64, 110, 270, 862 mg/m³ (analytical)

No. of animals per sex per dose:

5

Control animals:

yes

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

ca. 59 mg/m³ air

Exp. duration:

4 h

Mortality:

Number of deaths at each dose (time of death), male rats: 3 mg/m³: 0/5; 7 mg/m³: 0/5; 32 mg/m³: 0/5; 56 mg/m³: 0/5; 64 mg/m³: 4/5 (10d-14d); 110 mg/m³: 5/5 (2d-9d); 270 mg/m³: 5/5 (1d-2d); 862 mg/m³: 5/5 (<4h) Number of deaths at each dose (time of death), female rats: 3 mg/m³: 0/5; 7 mg/m³: 0/5; 32 mg/m³: 0/5; 56 mg/m³: 3/5 (9d-19d); 64 mg/m³: 3/5 (11d-15d); 110 mg/m³: 5/5 (8d-16d); 270 mg/m³: 5/5 (1d-8d); 862 mg/m³: 5/5 (4h/1d)

Clinical signs:

other: Number of animals with clinical signs, male rats: 3 mg/m³: 0/5; >= 7 mg/m³: 5/5 showed during the exposure and up to 28d after the exposure decreased motility, piloerection, exsudate of nostris, cyanosis; rhinitis like vocalization, labored breathing, br

Body weight:

BODY WEIGHT: >= 32 mg/m³: body weight retardation

Gross pathology:

NECROPSY: rats died during the post observation period: distended lungs, pale liver, spleen, and kidneys, gastrointestinal tract was filled with a yellow mucous or bloody mucous mass, reddening of the intestinal mucosa, sporadic ulcus like foci in intestinal mucosa, lobular pattern of the liver, pulmonary edema, and hydrothorax; liver like changes in the lung; blood-incrusted and reddened noses with serous discharge  rats sacrificed at the end of the post observation period: no lung lesions in the control and 3 mg/m³ dose group animals; the animals of the other dose groups showed significant gross findings in the lung

Other findings:

REFLEX EXAMINATION: no substance induced effects
RECTAL TEMPERATURE: concentration dependent decrease
VALUE: NOEL = 3 mg/m³ the LC50-value is true for both sexes

Any other information on results incl. tables

the LC50-value is true for both sexes

 

Applicant's summary and conclusion

Interpretation of results:

highly toxic

Remarks:

Migrated information

Executive summary:

ADMINISTRATION:
vapor inhalation under dynamic head-nose only exposure conditions
post observation period: approx. 4 weeks
nominal concentrations: 13; 21; 54; 83; 108; 187; 399; 1077 mg/m³
analytical concentrations: 3.1; 7.2; 31.7; 55.6; 63.6; 109.8; 270.3; 861.9 mg/m³
EXAMINATIONS:
mortality; clinical signs; body weight; rectal temperature,reflex, necropsy

LC50 = 59 mg/m³ (rat, male/female)