2,2-dimethylbutane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1970

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This study is classified as reliable with restrictions because it is an acceptable well-documented publication which meets basic scientific principles.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1970

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This study is classified as reliable with restrictions because it is an acceptable well-documented publication which meets basic scientific principles.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Remarks:

Pre-GLP study

Test type:

acute toxic class method

Species:

rat

Strain:

Long-Evans

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 150-300 g

Route of administration:

inhalation: vapour

Type of inhalation exposure:

not specified

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure chamber volume: 250 l
- Method of conditioning air: Sample was heated in a water bath at 77 degree F. Air was bubbled through the sample and entered the exposure chamber. For concentrations less than saturation, air flow was divided with part passing over the sample and part passing directly into the exposure chamber.

TEST ATMOSPHERE
- Brief description of analytical method used: GLC

Duration of exposure:

4 h

Concentrations:

73,680 ppm (30-40% of saturation at 25 degree C)
81,800 ppm

No. of animals per sex per dose:

10 males

Details on study design:

- Duration of observation period following administration: at least 6 days

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

73 860 ppm

Exp. duration:

4 h

Remarks on result:

other: 259354 mg/m3

Mortality:

All deaths occurred during exposure, except one rat in the 81800 ppm group that died on day 6.

Clinical signs:

other: Surviving rats were uncoordinated, prostrate or comatose during exposure but recovered within a few hours of removal from the chamber. The rat that died on day 6 had convulsions during and after exposure.

Interpretation of results:

study cannot be used for classification

Conclusions:

The 4-hr LC50 for rats exposed by inhalation was 73,680 ppm.

Executive summary:

This study examined that acute inhalation toxicity of hexane to male rats. Groups of 10 male rats exposed to various large concentrations of hexane vapor for 4 hrs. Animals were then observed for clinical signs and mortality for at least the next 6 days.

Several animals died during the exposure period. Surviving animals experienced severe toxicological effects during the exposure. One animal experienced convulsions during and after exposure, and died on day 6 post-exposure. The LC₅₀ was determined to be 73,680 ppm (259354 mg/m³). Due to the high concentration of the LC₅₀, the test substance would not be classified as toxic by inhalation according to OECD GHS guidelines.

Data source

Reference

Reference Type:

publication

Title:

The Toxicological Properties of Hydrocarbon Solvents

Author:

Hine, CH, and Zuidema, HH

Year:

1970

Bibliographic source:

Industrial Medicine, Vol. 39, No. 5, May 1970.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Remarks:

Pre-GLP study

Test type:

acute toxic class method

Test material

Test material information

Constituent 1

Reference substance name:

C-6 normal and iso paraffins (hexanes) and naphthenes (methyl-cyclohexane, dimethylcyclohexane), 25-35% n-hexane

IUPAC Name:

C-6 normal and iso paraffins (hexanes) and naphthenes (methyl-cyclohexane, dimethylcyclohexane), 25-35% n-hexane

Details on test material:

- Name of test material (as cited in study report): S-1
- Composition of test material, percentage of components: C-6 normal and iso paraffins (hexanes) and naphthenes (methyl-cyclohexane, dimethylcyclohexane), 25-35% n-hexane

Test animals

Species:

rat

Strain:

Long-Evans

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 150-300 g

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

not specified

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure chamber volume: 250 l
- Method of conditioning air: Sample was heated in a water bath at 77 degree F. Air was bubbled through the sample and entered the exposure chamber. For concentrations less than saturation, air flow was divided with part passing over the sample and part passing directly into the exposure chamber.

TEST ATMOSPHERE
- Brief description of analytical method used: GLC

Duration of exposure:

4 h

Concentrations:

73,680 ppm (30-40% of saturation at 25 degree C)
81,800 ppm

No. of animals per sex per dose:

10 males

Details on study design:

- Duration of observation period following administration: at least 6 days

Results and discussion

Effect levels

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

73 860 ppm

Exp. duration:

4 h

Remarks on result:

other: 259354 mg/m3

Mortality:

All deaths occurred during exposure, except one rat in the 81800 ppm group that died on day 6.

Clinical signs:

other: Surviving rats were uncoordinated, prostrate or comatose during exposure but recovered within a few hours of removal from the chamber. The rat that died on day 6 had convulsions during and after exposure.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

The 4-hr LC50 for rats exposed by inhalation was 73,680 ppm.

Executive summary:

This study examined that acute inhalation toxicity of hexane to male rats. Groups of 10 male rats exposed to various large concentrations of hexane vapor for 4 hrs. Animals were then observed for clinical signs and mortality for at least the next 6 days.

Several animals died during the exposure period. Surviving animals experienced severe toxicological effects during the exposure. One animal experienced convulsions during and after exposure, and died on day 6 post-exposure. The LC₅₀ was determined to be 73,680 ppm (259354 mg/m³). Due to the high concentration of the LC₅₀, the test substance would not be classified as toxic by inhalation according to OECD GHS guidelines.