Ethylene

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published in peer reviewed literature, non-guideline animal experimental study. Predates implementation of GLP. Limitations in reporting but scientifically acceptable and otherwise adequate for assessment.

Justification for type of information:

N/A

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1978

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Single acute ethylene exposure (4 hrs) (following 3 day gavage pre-treatment with Arochlor 1254).

GLP compliance:

no

Test type:

other: LC50

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Ethylene

EC Number:

200-815-3

EC Name:

Ethylene

Cas Number:

74-85-1

Molecular formula:

C2H4

IUPAC Name:

ethene

Details on test material:

- Name of test material (as cited in study report): ethylene
- Physical state: Gas
- Analytical purity: Purity not reported; described as highest purity
- No further data

Specific details on test material used for the study:

not specified

Test animals

Species:

rat

Strain:

other: Holtzman

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: No data
- Age at study initiation: 170-250 g
- Weight at study initiation: No data
- Housing: 5 or 6 per cage
- Diet: Purina rat chow (Ralston Purina Co., St Louis, Mo, USA), ad libitum except during exposure
- Water: ad libitum
- Acclimation period: No data

ENVIRONMENTAL CONDITIONS
- No data
- Photoperiod: 12 hrs dark / 12 hrs light

IN-LIFE DATES: no data

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure:

not specified

Vehicle:

other: air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Animals were exposed using inhalation chambers as described by Leach (1963); modified to allow regulation of the interior temperature.

TEST ATMOSPHERE
- Brief description of analytical method used: Chamber concentrations were monitored using a gas chromatograph with a flame ionization detector and a 5 foot column of Porapak Q.
- Samples taken from breathing zone: no data

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gas chromatograph

Duration of exposure:

4 h

Concentrations:

10000, 25000, or 57000 ppm (11, 473, 28700 or 65400 mg/m3)

No. of animals per sex per dose:

7

Control animals:

yes

Details on study design:

- Male rats were administered Aroclor 1254 (300 µmole/kg) via gavage, once daily for 3 days, prior to inhalation exposure to ethylene
- Animals were exposed on the 4th day for 4 hours
- Duration of observation period following administration: Animals were killed 24 hrs following exposure

Statistics:

 Dose-response data were analyzed using analysis of variance (ANOVA) where p <0.05 was considered significant.

Results and discussion

Preliminary study:

N/A

Effect levels

Effect levels 1

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

> 57 000 ppm

Exp. duration:

4 h

Remarks on result:

other: no mortality at highest dose tested

Effect levels 2

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

> 65 400 mg/m³ air

Exp. duration:

4 h

Remarks on result:

other: no mortality at highest dose tested

Mortality:

None (0/7) each dose level

Clinical signs:

other: None reported

Body weight:

Not reported

Gross pathology:

None done

Other findings:

N/A

Any other information on results incl. tables

The authors report that rats that were exposed to ethylene, but not pre-treated with Aroclor, showed no observable changes in the liver (no further detail or animal numbers reported).

Applicant's summary and conclusion

Interpretation of results:

other: not classified

Remarks:

Criteria used for interpretation of results: other: EU (DSD)

Conclusions:

The acute inhalation toxicity (4 hour) of ethylene is >57000 ppm ( 65400 mg/m3 or 65.4 mg/L).

Executive summary:

This study was not conducted with the intention of determining an LC50 value. However, acute toxicity via the inhalation route (4 hrs) was assessed following high dose exposure to ethylene at 10000, 25000, or 57000 ppm (11, 473, 28700 or 65400 mg/m3). In all cases exposure was preceded by 3 days gavage pre-treatment with Arochlor 1254.

No deaths occurred within the first 24 hrs in any dose group following exposure which suggests that the LC50 (4h) is greater than 57000 ppm (65.4 mg/L).

The authors report that rats that were exposed to ethylene, but not pre-treated with Aroclor, showed no observable changes in the liver.