N,N''-(isobutylidene)diurea

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Unsuitable test system

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1967

Report date:

1967

Materials and methods

Principles of method if other than guideline:

The test demonstrates the toxicity of an atmosphere enriched with the dusty parts of the test substance at 20 °C. Young adult laboratory rats, 6 per
sex, were exposed sequentially to the dusts generated by blowing 200 L/h air through a substance column of about 5 cm above a fritted glass disc in a glass cylinder for 8 h. The exposure was subsequently repeated in the same manner. No analytical determination of the atmosphere concentrations was performed. The nominal concentration was calculated as quotient of the amount of test substance weight loss during exposure, and the amount of
air used during exposure. Group-wise documentation of clinical signs was performed over a 7 day study period. Body weight of groups was determined before the start of the study and at the end of the observation period. Gross necropsy of the animals was performed after death of the animals or at
the end of the study.

GLP compliance:

no

Test type:

other: Inhalation Risk Test

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Details on test material:

- Name of test material (as cited in study report): Isobutylidendiharnstoff (IBU)
- Physical state: solid
- Analytical purity: ca. 90-96%
- Impurities (identity and concentrations): ca. 0-3% urea, ca. 2% potassium sulfate)
- Storage condition of test material: room temperature

Test animals

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: mean weight: 164.5 g
no further data

ENVIRONMENTAL CONDITIONS
no data

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

other: air

Details on inhalation exposure:

no further data

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

8 h

Concentrations:

ca. 2.6 mg/l mean concentration (calculated from substance loss; moderate dust formation; air was led through a 5 cm layer of isobutylidenediurea at
a rate of 200 l/hour).

No. of animals per sex per dose:

6

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 7 days
- Frequency of observations and weighing: total body weights of all animals were taken at the beginning and the end of the study, observations were
made, frequency was not reported
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology

Statistics:

not applicable

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.6 mg/L air (nominal)

Exp. duration:

8 h

Effect levels 2

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.2 mg/L air (nominal)

Exp. duration:

4 h

Remarks on result:

other: calculated from 8 h value by using Haber's law.

Mortality:

No deaths occurred.

Clinical signs:

other: No clinical symptoms were observed

Body weight:

mean weight at the beginning of the study: ca. 164.5 g (12 rats together: 1974 g)
mean weight at study termination: ca. 186 g (12 rats together: 2231 g)

Gross pathology:

No pathological changes were noted at necropsy, that were attributed to the test substance