2,2,4-trimethylpentane

Endpoint summary

Description of key information

Acute toxicity oral LD₅₀ >5000 mg/kg bw in rats (OECD TG 401)

Acute toxicity dermal LD₅₀ >2000 mg/kg bw in rabbits (OECD TG 402)

Acute toxicity inhalation LC₅₀ >33520 mg/m³ in rats (OECD TG 403)

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study meets generally accepted scientific principles, acceptable for assessment.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

Limit test with 5000 mg/kg versus 2000 mg/kg as per guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

Limit test with 5000 mg/kg versus 2000 mg/kg as per guideline

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations daily; weighing on initiation and on days 7 and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Mortality:

No mortality occurred in any test animal over the 14-day observation period.

Clinical signs:

other: Clinical observations noted one-hour post exposure in 8 of 10 animals included depression, salivation, wheezing, rough coat, and soft feces. Two female rats appeared normal throughout the study. All animals appeared normal from day 2 through termination

Gross pathology:

No abnormal gross pathology findings were noted in any of the animals upon necropsy.

Interpretation of results:

other: not classified

Remarks:

Criteria used for interpretation of results: other: GHS, EU, 2007

Conclusions:

Based on the study design the test substance, 2,2,4-trimethylpentane, needs not to be classified.

Executive summary:

Based on the study design the test substance, 2,2,4 -trimethylpentane, needs not to be classified.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

> 5 000 mg/kg bw

Quality of whole database:

1 key substance specific study available for assessment.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

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: Study meets generally accepted scientific principles, acceptable for assessment. Vapour generation and analysis not well documented.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

- limit test concentration: 5 mg/L

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Duration of exposure:

4 h

Concentrations:

33.52 mg/L nominal concentration
21561.5 ± 776.32 ppm mean analytical concentration

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: day 2, 3, and 4 mentioned, not further specified
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

not reported

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 33.52 mg/L air (nominal)

Exp. duration:

4 h

Mortality:

No mortality occurred during the 14-day observattion period.

Clinical signs:

other: Exposure-related observations noted in all animals during the exposure period included lying prostrate in the cage and rapid respiration. All animals appeared normal throughout the post exposure period.

Body weight:

Sightly decreased body weights were noted in the males on day 2 post exposure and in the females on days 2, 3 and 4 post exposure.

Gross pathology:

No abnormal gross pathology observations were noted in any animals upon necropsy.

Inhalation LC50 > 33.52 mg/L air (nominal) for 4 hours in male and female rats.

Interpretation of results:

other: not classified

Remarks:

Criteria used for interpretation of results: other: GHS, EU, 2007

Conclusions:

Based on the study design the test substance, 2,2,4-trimethylpentane, needs not to be classified.

Executive summary:

Based on the study design the test substance, 2,2,4 -trimethylpentane needs not to be classified.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

> 33 520 mg/m³ air

Physical form:

inhalation: vapour

Quality of whole database:

1 key substance specific study available for assessment.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study meets generally accepted scientific principles, acceptable for assessment.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

Only 3 animals per sex versus 5 as per guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

Only 3 animals per sex versus 5 as per guideline

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Type of coverage:

not specified

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

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: observation continuous, weighing on initiation and days 7 and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, dermal score

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

No mortality occurred during the 14-day observation period.

Clinical signs:

other: All rabbits appeared normal throughout the study. Very slight dermal erythema was noted in all animals on day 1 after dosing, which persisted in one male and one female on day 3. All erythema had cleared by day 7. Very slight edema was noted in two males

Gross pathology:

No abnormal gross pathology was noted in any rabbits upon necropsy.

Interpretation of results:

other: not classified

Remarks:

Migrated information Criteria used for interpretation of results: other: GHS, EU, 2007

Conclusions:

Based on the study design the test substance, 2,2,4-trimethylpentane, needs not to be classified.

Executive summary:

Based on the study design the substance, 2,2,4 -trimethylpentane, needs not to be classified.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

> 2 000 mg/kg bw

Quality of whole database:

1 key substance specific study available for assessment.

Additional information

Oral

 

2,2,4-trimethylpentane

The acute oral LD₅₀ value in rats was greater than 5000 mg/kg for 2,2,4-trimethylpentane. Clinical observations noted one-hour post exposure in 8 of 10 animals included depression, salivation, wheezing, rough coat, and soft faeces. Two female rats appeared normal throughout the study. All animals appeared normal from day 2 through termination of the study. (Chevron Phillips, 1982).

 

Inhalation

 

2,2,4-trimethylpentane

Male and female Sprague-Dawley rats (5/sex/dose) were exposed to 2,2,4-trimethylpentane at a nominal concentration of 33520 mg/m³ (21561.5 ± 776.32 ppm mean analytical concentration) for 4 h in a study similar to OECD 403 (limit test). No mortality occurred during the 14-day observation period. Exposure-related observations noted in all animals during the exposure period included lying prostrate in the cage and rapid respiration. All animals appeared normal throughout the post exposure period. No abnormal gross pathology observations were noted in any animal upon necropsy. The LC₅₀ value was greater than the nominal concentration of 33520 mg/m³ (Chevron Phillips, 1982).

 

Dermal

 

2,2,4-trimethylpentane

The dermal LD₅₀ value of 2,2,4-trimethylpentane, as determined in rabbits, was greater than the limit dose of 2000 mg/kg. All rabbits appeared normal throughout the study. Very slight dermal erythema was noted in all animals on day 1 after dosing, which persisted in one male and one female on day 3. All erythema had cleared by day 7. Very slight oedema was noted in two males and one female on day 1 and cleared by day 3. Epidermal scaling was noted in one female on day 10 (Chevron Phillips, 1982).

Justification for classification or non-classification

Based on available data, 2,2,4-trimethylpentane is minimally toxic via ingestion where the LD₅₀ is >5000 mg/kg bw, via dermal exposure where the LD₅₀ is >2000 mg/kg bw, and by inhalation where the LC₅₀ is >33520 mg/m³. These findings do not warrant classification under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP).

2,2,4-trimethylpentane is classified under EU CLP guidelines as H336: STOT Single Exposure Category 3 (narcosis) based on non-lethal narcotic effects observed in acute inhalation exposure.

 

2,2,4-trimethylpentane is classified under EU CLP guidelines as a Category 1 aspiration hazard based on its physical and chemical properties (hydrocarbon fluid, viscosity ≤ 20.5 mm²/s).