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Toxicological information

Acute Toxicity: inhalation

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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: Test procedure in accordance with national standard methods

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Principles of method if other than guideline:
Seven groups of 5 male and 5 female rats were exposed nose/head only to vapours of 0, 0.7, 5.4, 15.2, 11.7, 27.9, 47.1 or 87.8 mg/m³ (analytical) tert-butylisocyanat for 4 hours. The animals were observed for mortality, body weight and clinical signs through week 4. A gross pathological examination was performed on animals which died intercurrent or were killed after termination of the study.
GLP compliance:
yes
Test type:
standard acute method

Test material

Constituent 1
Reference substance name:
109-86-5
IUPAC Name:
109-86-5
Constituent 2
Chemical structure
Reference substance name:
tert-butyl isocyanate
EC Number:
216-544-9
EC Name:
tert-butyl isocyanate
Cas Number:
1609-86-5
Molecular formula:
C5H9NO
IUPAC Name:
tert-butyl isocyanate
Details on test material:
content: 99.7%

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
nose/head only
Vehicle:
air
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
nominal: 0, 454, 1004, 1486, 1836, 2028, 3597 mg/m³
analytical: 0, 295.9, 777.9, 1071.8, 1144.3, 1391.5, 2510.3 mg/m³
No. of animals per sex per dose:
5 male and female rats/dose
Control animals:
yes

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
ca. 1 593 mg/m³ air
Exp. duration:
4 h

Any other information on results incl. tables

A concentration of 296 mg/m³ tert-butylisocyanate/ m³air ( 4 hr exposure) was tolerated without any clinical symptoms. Body weight was temporily influenced at a concentration of 778 mg/m³. A concentration of 1144 mg/m³ was the threshold of the mortality range.

Vapour of tert-butyl isocyanate is irritating to the respiratory tract.  Animals which died during the post-observation period showed inflated lungs. Liver, spleen and kidneys were pale. A bloddy mucous content was found in the inestinal tract. Mucosa of the intestines were reddened. A lung edema and hydrothorax was evident. Rats which were killed after the post-observation period had no visible macroscopic lung changes.

Applicant's summary and conclusion

Interpretation of results:
toxic
Remarks:
Migrated information
Executive summary:

Seven groups of 5 male and 5 female rats were exposed nose/head only to vapours of 0, 0.7, 5.4, 15.2, 11.7, 27.9, 47.1 or 87.8 mg/m³ (analytical) phenylisocyanat for 4 hours. The animals were observed for mortality, body weight and clinical signs through week 4. A gross pathological examination was performed on animals which died intercurrent or were killed after termination of the study.

A concentration of 296 mg/m³ tert-butyl isocyanate/ m³air ( 4 hr exposure) was tolerated without any clinical symptoms. Body weight was temporily influenced at a concentration of 778 mg/m³. A concentration of 1144 mg/kg was the threshold of the mortality range.

Vapour of tert-butyl isocyanate is irritating to the respiratory tract.  LC50 = 1695 mg/m³ tert-butyl isocyanate/m³ air (rat, male + female). The NOEL was 296 mg/m³ tert-butyl isocyanate/m³ air.