Isobutyric anhydride

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non standard test design, with little reporting detail

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1978

Report date:

1978

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Inhalation-Risk-Test was performed in principle as described in OECD Guideline 403 (adopted 1981). It demonstrates the toxicity of an atmosphere saturated with vapors of the volatile components of a test substance at the temperature chosen for vapor generation (20°C).

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Isobutyric anhydride

EC Number:

202-603-6

EC Name:

Isobutyric anhydride

Cas Number:

97-72-3

Molecular formula:

C8H14O3

IUPAC Name:

isobutyric anhydride

Details on test material:

- Physical state: liquid
no further data provided

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: mean: male: 228 g; female: 196 g

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Source and rate of air: 200L air/h
- System of generating particulates/aerosols: Vapor is generated by bubbling 200 L/h air at 20°C through a substance column of about 5 cm above a fritted glass disc in a glass cylinder for 1, 3 and 7 hours.
- Pressure in air chamber: 755 mm/Hg

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

7 h

Concentrations:

mean: 7 hours: 4.21 mg/L; 3 hours: 4.18 mg/L; 1 hours: 4.27 mg/L

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: daily, weighing at beginning and at the end of the study
- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

ca. 4.21 mg/L air

Based on:

test mat.

Exp. duration:

7 h

Mortality:

1 male rat died after 3 h exposure on day one after exposure.
1 male rat died after 7 h exposure on day one after exposure further 3 animals died on day 2.
In the 1 hour exposure test no animal died.

Clinical signs:

other: Eyelid closure, clear and bloody discharge (nose), piloerection and dyspnea were seen as long as the animals were under exposure. At the 7 hour exposure dyspnea and crust formation at the nose were seen until day 6.

Body weight:

Normal body weight gain.

Gross pathology:

All dead animals showed in the heart an acute dilation (right) and an acute congestion. One animal showed a blood filled lung after infarct. In sacrificed animals were no abnormalities detected.