Benzene

Endpoint summary

Description of key information

Based on limited animal and human experimental data, and no reports in humans of skin sensitisation, benzene is considered not to be a skin sensitiser. As benzene is a mutagen and a carcinogen, human exposure is minimised by the implementation of appropriate risk management measures. Benzene is produced and used under strictly controlled conditions.

There is no evidence from animal experimental inhalation studies, or from human experience, to indicate that benzene is a respiratory sensitiser.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-guideline, non- GLP animal experimental study, limitations in design and reporting but otherwise adequate for assessment.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

only 15 test and 6 control animals in GMPT

Qualifier:

no guideline available

GLP compliance:

not specified

Type of study:

other: GPMT and mouse ear swelling test (MEST)

Species:

other: mouse and guinea pig

Strain:

other: CF-1 mouse and Hartley guinea pigs

Sex:

not specified

Details on test animals and environmental conditions:

Specific details for benzene cannot be deduced from paper

Route:

intradermal and epicutaneous

Vehicle:

unchanged (no vehicle)

Concentration / amount:

MEST: Induction and challenge neat (100%)
GPMT: Intradermal injection and topical induction application and challenge application neat (100%)

Route:

epicutaneous, semiocclusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

MEST: Induction and challenge neat (100%)
GPMT: Intradermal injection and topical induction application and challenge application neat (100%)

No. of animals per dose:

MEST: 10- 15 females per test group, 5-10 control group
GPMT: 15 per test group, 6 in control group

Key result

Reading:

other: Overall

Hours after challenge:

48

Group:

test chemical

Dose level:

100 µl

Remarks on result:

no indication of skin sensitisation

MEST: 0% sensitised, 100% swelling

GPMT: 0% sensitised

Interpretation of results:

not sensitising

Conclusions:

Under the conditions of the MEST and limited GPMT studies described, benzene was not a skin sensitizer.

Executive summary:

The skin sensitisation potential of benzene was assessed in a mouse ear swelling test (MEST) and a reduced guinea pig maximisation test (GPMT) using neat benzene. None of the mice and none of the guinea pigs showed any evidence of sensitisation.

It is concluded that benzene is not a strong sensitizer and does not warrant labelling under CLP or GHS.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Non-human information

Although there are no GLP guideline compliant studies the skin sensitisation potential of benzene was assessed in a mouse ear swelling test (MEST) and a reduced guinea pig maximisation test (GPMT) using neat benzene. None of the mice and none of the guinea pigs showed any evidence of sensitisation (Gad et al, 1986).

Human information

In a study using 25 male volunteers a maximisation test with induction using 50% benzene and challenge with 20% benzene no evidence of skin sensitisation was seen (0/25) (Kligman, 1966).

Justification for selection of skin sensitisation endpoint:
Benzene was not a dermal sensitiser when assessed in a mouse ear swelling test (MEST) and a guinea pig maximisation test (GPMT). No evidence of skin sensitisation was found in a human maximisation test.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Non-human information

There is no evidence from animal experimental studies that benzene is a respiratory sensitiser

Human Information

There are no reports of human respiratory sensitisation to benzene despite more than 100 years of human experience with benzene which was commonly used as a solvent. As benzene is a mutagen and a carcinogen, human exposure is minimised by the implementation of appropriate risk management measures. Benzene is produced and used under strictly controlled conditions.

Justification for classification or non-classification

It is concluded that benzene is not a skin or respiratory sensitiser and does not warrant labelling under (EC) No 1272/2008 of the European Parliament.