5-methylhexan-2-one

Endpoint summary

Description of key information

- open epicutaneous test with repeated exposure: study conducted according to an internal Eastman Kodak Company laboratory method; guinea pigs (Hartley; m/f), application most likely open cutaneous. A weak allergic response was observed in one of five guinea pigs, while the other four animals exhibited no response. The overall result: 5-methylhexan-2-one does not trigger C&L as skin sensitizer.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted prior to introduction of Good Laboratory Practices; data from a summary report; insufficient experimental detail; actual test report not available for review. Study was conducted by an internal Eastman Kodak Company method, developed prior to established guidelines.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Deviations:

not specified

Principles of method if other than guideline:

Not specified; method used is most like the Open Epicutaneous Test in which the test substance is repeatedly applied topically, and subsequently evaluated for any increase in the dermal reaction elicited.

GLP compliance:

no

Type of study:

other: Study conducted according to an internal Eastman Kodak Company laboratory method, not used elsewhere.

Justification for non-LLNA method:

This in vivo the Open Epicutaneous Test - in which the test substance is repeatedly applied topically to Guinea pig skin, and the dermal reaction elicited was evaluated - was available before conduct of in vitro tests were judged to be the preferred method.

Species:

guinea pig

Strain:

Hartley

Sex:

not specified

Details on test animals and environmental conditions:

no data

Route:

other: Not specified; most likely open epicutaneous

Vehicle:

no data

Concentration / amount:

no data

Route:

other: Not specified; most likely open epicutaneous

Vehicle:

no data

Concentration / amount:

no data

No. of animals per dose:

5 animals in test group (sex not reported)

Details on study design:

no data

Challenge controls:

no data

Positive control substance(s):

not specified

Reading:

1st reading

Group:

test chemical

Dose level:

no data

No. with + reactions:

1

Total no. in group:

5

Clinical observations:

A weak allergic response was observed in one of five guinea pigs.

Remarks on result:

other: Reading: 1st reading. Group: test group. Dose level: no data. No with. + reactions: 1.0. Total no. in groups: 5.0. Clinical observations: A weak allergic response was observed in one of five guinea pigs..

Reading:

1st reading

Group:

negative control

Remarks on result:

other: not specified in detail

Remarks:

please refer to results for test groups given above

Reading:

1st reading

Group:

positive control

Remarks on result:

other: not specified in detail

Remarks:

please refer to results for test groups given above

Interpretation of results:

other:

Remarks:

EU-GHS criteria not met

Conclusions:

One of five guinea pigs displayed a weak allergic response following a presumed open epicutaneous exposure to methyl isoamyl ketone. No sensitization responses were observed in the four remaining animals. Based on the results of this study, methyl isoamyl ketone is not expected to be classified for sensitization by skin contact under EU-GHS.

Executive summary:

In a skin sensitization study using an Eastman Kodak Company study design, five guinea pigs were induced and challenged by presumed open epicutaneous exposure to methyl isoamyl ketone. Skin examinations after the challenge dose indicated no positive sensitization reactions were evident in four of the five animals. Only a weak allergic response was reported in the remaining animal after the challenge application. Based on results of this study, methyl isoamyl ketone is not considered to be a skin sensitizer in guinea pigs, and therefore, presents a low skin sensitization hazard upon skin contact under conditions of normal use.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Skin sensitisation

The potential for methyl isoamyl ketone to cause dermal sensitization was evaluated using a non-guideline study in which guinea pigs were repeatedly exposed to the test material using an open epicutaneous method. One of five animals displayed a weak allergic response while the four remaining animals exhibited no response. In addition, guinea pigs receiving 7 applications of the test material over a 10-day period in a repeated skin irritation study showed no evidence of a sensitization response. Slight to moderate erythema in 2 of 5 animals and dry skin with cracked eschars in all animals in this study were more likely due to the drying effects of repeated solvent exposure than to a sensitization response.

Justification for classification or non-classification

No evidence of a sensitization response was observed when guinea pigs were exposed to the test material in a dermal sensitization study or a repeat-exposure dermal irritation study. 

Based on a weight-of-the-evidence assessment, methyl isoamyl ketone is not classified for “Skin Sensitization” according to EU-GHS guidelines.