Isooctene

Endpoint summary

Description of key information

In an oral limit dose toxicity test, there were no deaths in rats following a single dose of 10,000 mg/kg isooctene.  No data are available for acute toxicity of isooctene via dermal and inhalation routes.

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: non-GLP, guideline study, fully adequate for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SPF TNO
- Weight at study initiation: 118.6 g
- Fasting period before study: 16 hours
- Housing: stainless steel cages
- Diet: R10 Alleindiat for rats ad libitum
- Water: tap water ad libitum
- Acclimatisation period: 4-8 days

ENVIRONMENTAL CONDITIONS
- Temperature: 20±1°C
- Humidity: 60±5%
- Air changes: 15 per hr
- Photoperiod: 12 hrs dark / 12 hrs light

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Doses:

13699 cm3/kg

No. of animals per sex per dose:

5 per sex (total 10)

Control animals:

no

Details on study design:

- Animals were randomly allocated to stainless steel cages
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations at 6 hours after dosing and daily. Animals were weighed at 1, 7 and 14 days.
- Necropsy of survivors performed: yes
- Other examinations performed: necropsy with macroscopic examination

Statistics:

LD50 calculated following Litchfield and Wilcoxon method with 95% confidence intervals.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 10 000 mg/kg bw

Mortality:

None

Clinical signs:

other: After one hour the animals exhibited piloerection. Then animals crouched, had slight tremors, diuresis, lightly coloured faeces with a strong smell of the test substance. After 48 hours the animals were free of these clinical signs.

Gross pathology:

One animal had partial thickening of the forestomach and another had partial hyperaemia of the small intestine membrane.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The LD50 of di-n-butene in rats was >10,000 mg/kg. Animals were free of clinical signs after 48 hours. At necropsy, one animal had partial thickening of the forestomach and another had partial hyperaemia of the small intestine membrane.

Executive summary:

Following a single oral dose of 10,000 mg/kg, none of the animals died. The LD50 of di-n-butene in rats was >10,000 mg/kg.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Non human data

Oral

In a limit test, there were no deaths in rats following a single oral dose of 10,000 mg/kg isooctene (18% n-octene, 58% methylheptene and 24% dimethylhexene isomers) (Huels AG, 1986a).  Piloerection, tremors and diuresis were observed in the treated rats one hour after dosing. 

Dermal

No data available

Inhalation 

No data available

Aspiration hazard

This is a known hazard of hydrocarbons, although there is no evidence of aspiration hazard from the animal studies considered.

Human data

No data available

Justification for classification or non-classification

Isooctene does not warrant classification under DSD or CLP for acute toxicity via the oral inhalation route of exposure.

Aspiration is a known hazard of hydrocarbons and, although there is no evidence of aspiration hazard from the animal studies considered, classification is based on the physical characteristics of isooctene which has a kinematic viscosity below the cut off values for DSD of 7mm²/s and for CLP of 20.5 mm²/s for hydrocarbons and therefore classification is warranted. Classification as Xn; R65 Harmful; Harmful: may cause lung damage if swallowed under DSD and Cat 1 H304 May be fatal if swallowed and enters airways is warranted.