Buta-1,2-diene

Acute Toxicity: inhalation

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:

other: Non GLP, near guideline study, available as published report, minor restrictions in design and/or reporting but otherwise adequate for assessment

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Deviations:

not specified

Remarks:

(near guideline study)

Principles of method if other than guideline:

Not applicable

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,2-butadiene

IUPAC Name:

1,2-butadiene

Details on test material:

- Name of test material (as cited in study report): 1,2-butadiene
- Physical state: liquid-gas
- Analytical purity: 92-93%

Test animals

Species:

rat

Strain:

other: Cpb:Wu, Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Central institute for the breeding of laboratory animals TNO, Zeist, The Netherlands
- Age at study initiation: no data
- Weight at study initiation: mean bodyweight: 182 g (males) and 138 g (females)
- Housing: 5 per cage by sex in stainless steel suspended cages
- Diet: Stock diet ad libitum except during exposure
- Bottled unflouridated water: ad libitum except during exposure
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature: 21±1°C
- Humidity: 40-60%
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): not reported

IN-LIFE DATES: From: 30 November 1979 To: 14 December 1979

Administration / exposure

Route of administration:

inhalation: gas

Type of inhalation exposure:

not specified

Vehicle:

other: air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The animals were exposed to the test substance in a horizontally placed glass cylinder (0.90 x 0.15 m) with sampling ports at the inlet and at the outlet part of the exposure cylinder. Two of these cylinders were used, one for the control animals and one for the test animals; each of them was fitted with an interior of perforated stainless steel plate to separately accommodate ten rats.
- A test atmosphere containing a maximum of 8% v/v 1,2-butadiene was used.
- A measured flow of 1,2-butadiene from the cylinder containing the liquid gas was mixed with the filtered compressor generated air-flow to obtain the maximum admissible concentration of 0.8 per cent (V/V) 1,2-butadiene in the atmosphere.
- Rate of air: The total air-flow per cylinder was 8 L/min.
- Temperature in the chamber: The cylinders were kept at a temperature of 23°C

TEST ATMOSPHERE
- Brief description of analytical method used: Analyses of the test atmosphere were performed by gas chromatography, with an Intersmat GC 120, that was fitted with a flame ionization detector.
- To monitor the 1,2-butadiene concentration in the test atmosphere, samples were taken automatically at regular intervals by means of a stainless steel sampling tube and sample loop using a membrane pump and a timer-controlled 7-port gas-sampling valve.
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Remarks:

The mean actual concentration of 1,2-butadiene during the 4-hour exposure period was 0.8±0.005% (v/v).

Duration of exposure:

4 h

Concentrations:

0.8% v/v

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Control animals were exposed to air only
- Duration of observation period following administration: 14 days
- Frequency of weighing: on days 0, 1, 2, 4, 7 and 14
- Necropsy of survivors performed: yes; samples of kidney, liver, lungs with trachea and larynx were processed and examined microscopically.

Statistics:

none required
.

Results and discussion

Preliminary study:

none

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

0.8 other: %

Exp. duration:

4 h

Remarks on result:

other: 8000ppm; (17,701 mg/m3)

Mortality:

None of the animals died.

Clinical signs:

other: During the first twenty minutes of the exposure period the rats of the 1,2-butadiene group were somewhat restless; thereafter they were sitting motionless and were asleep. During the observation period the behaviour of the animals of the 1,2-butadiene gro

Body weight:

During the first day of the observation period both males and females lost body weight. Thereafter, males gained body weight at a rate similar to that of the control animals. Females of the test group did not grow during the first week, but grew in a normal way during the second week of the observation period.

Gross pathology:

Gross examination at autopsy and microscopic examination of kidneys, liver, lungs, trachea and larynx did not reveal any alterations which could be ascribed to the exposure of the animals to 1,2-butadiene.

Other findings:

none

Any other information on results incl. tables

none

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Acute inhalation exposure to 1,2-butadiene at a concentration of 0.8% (v/v) for a period of 4 hours did not result in mortality or in abnormal behaviour in rats.

Executive summary:

An acute inhalation toxicity test on 1,2-butadiene was carried out in rats. No mortality or in abnormal behaviour occurred. The animals slept throughout the exposure period. The LC50 of 1,2-butadiene was greater than 0.8% (v/v) (8000ppm, 17,701 mg/m³). Higher concentrations could not be tested because of the risk of explosion.