Isooctene

Endpoint summary

Description of key information

Isooctene is moderately irritating to skin and warrants classification under DSD and CLP.   Isooctene is not irritanting to eyes and there was no evidence of irritation of the respiratory tract in a repeat dose inhalation study.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

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, adequate for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

no

Species:

rabbit

Strain:

other: small white Russian CHbb-SPF

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr Karl Thomae GmbH, Biberach
- Weight at study initiation: 2.2-2.3 kg
- Housing: stainless steel cages
- Diet: K4 Alleindiat for rabbits ad libitum
- Water: tap water ad libitum
- Acclimatisation period: 14 days

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

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.5 cm3

Duration of treatment / exposure:

4 hours

Observation period:

1, 24, 48 and 72 hours post treatment and then at 6, 8, 10 and 14 days

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: ~6 cm2
- Type of wrap if used: Gauze (2.5 x 2.5 cm) and then with polyethylene film (6 x 6 cm), bound on to the animal

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes (warm water)
- Time after start of exposure: 4 hours

SCORING SYSTEM: OECD method

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 72 hours

Score:

2.22

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 72 hours

Score:

1.22

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Interpretation of results:

moderately irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Di-n-butene was irritating to rabbit skin after application of 0.5 cm3 test substance.

Executive summary:

Following a single 4 hour application, Di-n-butene was irritating to rabbit skin after application of 0.5 cm³ test substance.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

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, adequate for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

GLP compliance:

no

Species:

rabbit

Strain:

other: small, white Russian (Chbb-SPF)

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2.2 kg
- Housing: stainless steel cages
- Diet: K4 Alleindiat for rabbits ad libitum
- Water: tap water ad libitum
- Acclimatisation period: 14 days

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

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 cm3

Duration of treatment / exposure:

72 hours

Observation period (in vivo):

1, 24, 48 and 72 hours after application and also at 6 days after application

Number of animals or in vitro replicates:

3

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): saline solution
- Time after start of exposure: 72 hours

SCORING SYSTEM: Draize

TOOL USED TO ASSESS SCORE: hand-slit lamp and fluorescein

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 72 hours

Score:

0

Max. score:

0

Reversibility:

other: not relevant

Remarks on result:

other: score also 0 at 6 days

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 72 hours

Score:

0

Max. score:

0

Reversibility:

other: not relevant

Remarks on result:

other: score also 0 at 6 days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Time point:

other: 72 hours

Score:

0

Max. score:

0

Reversibility:

other: not relevant

Remarks on result:

other: score also 0 at 6 days

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 72 hours

Score:

0

Max. score:

0

Reversibility:

other: not relevant

Remarks on result:

other: score also 0 at 6 days

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the test conditions, di-n-butene was not irritating to rabbit eyes.

Executive summary:

Following a single application of 0.1 cm³, di-n-butene was not irritating to the rabbit eye.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

Non-human data

Skin Irritation

Isooctene (18% n-octene; and 58% methylheptene and 24% dimethylhexene isomers) was found to be irritating to the skin of rabbits when applied for 4 hours under occlusive conditions (Huels AG, 1986b). Both the erythema and edema were not fully reversible within 14 days of application.

Eye irritation

Instillation of 0.1 ml of undiluted isooctene (18% n-octene; and 58% methylheptene and 24% dimethylhexene isomers) was a non-irritant to the eyes of rabbits (Huels AG, 1986c).

Respiratory Tract Irritation

In the 13 week combined subchronic vapour inhalation study with reproduction/developmental toxicity screening test in Wistar rats with isooctene (BASF, 2007) there is no evidence of respiratory irritation.

Effects on skin irritation/corrosion: moderately irritating

Justification for classification or non-classification

Isooctene warrants classification as Xi R38 Irritating to the skin (DSD Dir 67/548/EEC) and Category 2 H315 Causes skin irritation (CLP)

Isooctene does not warrant classification for eye irritation under DSD or CLP.

Although there are no specific acute studies of respiratory irritation, longer term non human studies indicate no evidence of respiratory irritation and therefore classification is not warranted under DSD or CLP..