p-(trifluoromethoxy)phenyl isocyanate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Principles of method if other than guideline:

Five groups of 10 male and 10 female rats were exposed nose/head only to vapours of 4.5, 15.7, 22.5, 68.5, or 132 mg/m³ (analytical) 4-trifluoromethoxyphenyl isocyanate for 4 hours. The animals were observed for mortality, body weight and clinical signs up to day 21. A gross pathological examination was performed on animals which died intercurrent or were killed after termination of the study.

GLP compliance:

no

Test type:

standard acute method

Test material

Test material information

Constituent 1

Reference substance name:

p-(trifluoromethoxy)phenyl isocyanate

EC Number:

252-328-0

EC Name:

p-(trifluoromethoxy)phenyl isocyanate

Cas Number:

35037-73-1

Molecular formula:

C8H4F3NO2

IUPAC Name:

1-isocyanato-4-(trifluoromethoxy)benzene

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:

4.5, 15.7, 22.5, 68.5, or 132 mg/m³

No. of animals per sex per dose:

10 male and 10 female rats/dose

Control animals:

not specified

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

22.5 - 68.5 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

The animals which died intercurrent showed strong inflated, edematous, pale grey or dark red decolored lungs. Livers were pale and spotted., spleen and kidneys had a pale colour. The gastro-intestinal tract was filled with a reddish-mucous content.

Body weight:

Body weight gain was normal in males at 15.7 mg/m³.
Higher concentrations in males and all concentrations in females had a markedly influence on body weight.

Other findings:

At a concentration of 15.7 mg/m³ air the rats showed an unspecific abnormal behaviour (lethargy, scruffy fur) and laboured breathing. up to 3 days after exposition. With higher concentrations these symptoms were present until death or termination of the study. Clear signs of irritation on the visible mucosa of the eyes and nose were evident.  

Up to a concentration of 15.7 mg/m³ no evidence of organ damages were found.

Animals killed after the post-observation period had pale or greyish discoloured, inflated lungs on concentrations above 22.5 mg/m³

Applicant's summary and conclusion

Interpretation of results:

Category 1 based on GHS criteria

Remarks:

Based on EU GHS criteria

Conclusions:

Test item showed a strong irritating effect on the mucous membranes. The LC50 was 22.5 - 68.5 mg/m³ (0.0225 - 0.0685mg/L) for male and female rats.

Executive summary:

Five groups of 10 male and 10 female rats were exposed nose/head only to vapours of 4.5, 15.7, 22.5, 68.5, or 132 mg/m³ (analytical) 4-trifluoromethoxyphenyl isocyanat for 4 hours. The animals were observed for mortality, body weight and clinical signs up to day 21. A gross pathological examination was performed on animals which died intercurrent or were killed after termination of the study.

4-trifluoromethoxyphenyl isocyanate showed a strong irritating effect on the mucous membranes. The LC50 was 22.5 - 68.5 mg/m³ (0.0225 - 0.0685mg/L) for male and female rats.