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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:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1974
Report Date:
1974

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Version / remarks:
: Inhalation hazard test as described in the Annex
GLP compliance:
no
Test type:
other: Inhalation hazard test
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Isobuttersaeure (Propanoic acid, 2-methyl-)
- Analytical purity: 99 %

Test animals

Species:
rat
Strain:
not specified
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 213 g (mean)

Administration / exposure

Route of administration:
inhalation: vapour
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
Rats exposed for 3 h, 8 h, respectively, to a vapour saturated atmosphere. Vapour was generated by bubbling 200 l/h dry air (no CO2) through the liquid substance column (volume ca. 50 ml) of about 5 cm above a fritted glass disc in a glass cylinder. The glas cylinder was heated in a water bath. The air pressure was 754 mm Hg. Temperature in the exposure chamber was 20°C.

Duration of exposure:
8 h
Concentrations:
9.59 mg/l
No. of animals per sex per dose:
6
Control animals:
yes
Details on study design:
- Duration of observation period following administration:7 days
- Other examinations performed: clinical signs

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC0
Effect level:
9.59 mg/L air
Exp. duration:
8 h
Remarks on result:
other: Inhalation Hazard Tests
Mortality:
No Mortality was observed.
Clinical signs:
other: severe mucosal irritation at exposure, day 1 dyspnea (1/12)
Body weight:
Body weight development was positive and with in the normal range
Gross pathology:
nothing abnormal was detected

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Remarks:
Criteria used for interpretation of results: other: OECD TG 403
Conclusions:
Isobutyric acid did not cause any mortality within 7 days after exposure of six male and six female rats for 8 hours to an approximately vapor saturated atmosphere (ca. 9.59 mg/L).
Executive summary:

This acute inhalation toxicity test was performed as Inhalation Hazard Test. Six male and six female rats were exposed for 8 hr to an atmosphere saturated or close to saturation with vapors of isobutyric acid. Breathing atmosphere concentrations are reported as 9.59 mg/L air.

 

Under the conditions of this test, no mortality was observed for the extended exposure period of 8 hr (BASF AG, 1974).

 

The test concentration of 9.59 mg/L air of this test exceeds the limit concentration (5 mg/L) of OECD TG 403 for a limit test but not the limit concentration for vapors (20 mg/L) of EU TG B.2. According to the criteria of OECD test guideline 403 (Acute Inhalation Toxicity), it can be assumed that there is no likely inhalation hazard for isobutyric acid under normal conditions of exposure.

 

Standards of the OECD test guideline 403 (Acute Inhalation Toxicity) are only met with restrictions by this investigation (observation period 7 days). A LC50 was not determined. Nevertheless, the results of the study are regarded as being valuable. Deviations from the test guideline are considered not to influence the results in a way that the reported results could not be relied on.