Solvent naphtha (coal), xylene-styrene cut

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-guideline study, GLP status not known, published in peer reviewed literature, no restrictions, fully adequate for assessment.

Data source

Reference

Reference Type:

publication

Title:

The identification of contact allergens by human assay III. The maximisation test: A procedure for screening and rating contact sensitizers

Author:

Kligman AM

Year:

1966

Bibliographic source:

J. Invest. Derm. Vol 47, 393-409

Materials and methods

Study type:

study with volunteers

Endpoint addressed:

skin sensitisation

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

25 healthy adult males were used. Two main procedures were involved; (a) the potential induction of an immune response; (b) a challenge of that response.
Induction: 1.0 mL of undiluted xylene was applied on "Webril" patches (1.5" x 1.5") under an occlusive dressing to the forearm or calf of the subject. There was a total of five 48 hour exposures to exactly the same skin site. For 24 hours before each application 1.0 mL of 5% aqueous sodium lauryl sulphate (irritant) was administered.
Challenge: 0.4 mL of 5% aqueous sodium lauryl sulphate was applied on "Webril" patches (1" x 1") under an occlusive dressing to the back for 1 hour followed by undiluted xylene for 48 hours. The challenge reaction is assessed immediately after removal of the dressing and again 2 days later and the degree of sensitisation classified on a 1-5 scale.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

mixed xylenes

IUPAC Name:

mixed xylenes

Constituent 2

Reference substance name:

Xylene

EC Number:

215-535-7

EC Name:

Xylene

Cas Number:

1330-20-7

Molecular formula:

C8H10

IUPAC Name:

xylene

Details on test material:

No further details

Method

Type of population:

other: volunteer

Subjects:

25 males (90% were black) aged 18 - 50 years.

Ethical approval:

not specified

Route of exposure:

dermal

Reason of exposure:

intentional

Exposure assessment:

measured

Details on exposure:

A total of five applications of undiluted test material to inflamed skin on the forearm or calf (same site on each occasion, pre-treated with SLS) followed by challenge (100%, 25% mixed xylenes) on the back. An occlusive dressing was applied.

Results and discussion

Clinical signs:

None

Results of examinations:

The sensitisation rate was 0/24 indicating that mixed xylenes was not a skin sensitiser under the conditions of the study.

Any other information on results incl. tables

Mixed xylenes was not a sensitiser under the conditions of the study.

Applicant's summary and conclusion

Conclusions:

The human maximization test devised by Albert Kligman is a highly sensitive detector of skin sensitizing potential. In this assay, xylene was tested at 100% and subjects challenged at 25%. No skin sensitization resulted.

Executive summary:

The skin sensitisation potential of mixed xylenes was investigated in an early human maximisation test employing a total of five applications to inflamed skin on the forearm or calf (same site on each occasion, pre-treated with SLS) followed by challenge (100%, 25% mixed xylenes) on the back. The sensitisation rate was 0/24 indicating that mixed xylenes was not a skin sensitiser under the conditions of the study. The results for more than 80 chemicals are presented in this paper which demonstrates the very considerable predictive sensitivity of ths assay.