2-hydroxybenzoic acid 2-butyloctyl ester

Endpoint summary

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

Study period:

22 December 2008 to 30 January 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Principles of method if other than guideline:

Although not stated, the procedure used was essentially that of Draize (Procedures for the appraisal of the toxicity of chemicals in foods, drugs, and cosmetics. VIII. Dermal toxicity, Food Drug Cosmetic Law J. 10:722-731, 1955).

GLP compliance:

yes (incl. QA statement)

Type of study:

patch test

Species:

human

Strain:

other: not applicable

Sex:

male/female

Details on test animals and environmental conditions:

Participants:

Sixty-one (61) male and female ranging in age from 17 to 73 years of age. Fifty-three (53) subjects completed the study. The remaining subjects discontinued their participation for various reasons, none of which were related to the application of the test material.

Inclusion Criteria:

The following criteria applied to study participants: male and female, age 16 or older; an absence of any visible skin disease which might confuse the study results; prohibition on the use of topical or systemic steroids and/or antihistamines for at least seven days prior to study initiation; completion of medical history forms and informed consent forms; considered reliable and capable of following directions.

Exclusion Criteria:

The following applied: ill health; someone under a doctor's care and taking medication that might influence the outcome of the study; pregnant or nursing females; a history of adverse reactions to cosmetics or other personal care products.

Route:

epicutaneous, semiocclusive

Vehicle:

corn oil

Concentration / amount:

25%

Route:

epicutaneous, semiocclusive

Vehicle:

corn oil

Concentration / amount:

25%

No. of animals per dose:

53 participants completed the study

Details on study design:

Test Material Preparation:

The test material was prepared as a 25% dilution in corn oil.

Application Area:

The upper back between the scapulae served as the treatment area. Approximately 0.2 ml of the test material, or an amount sufficient to cover the contact surface, was applied to a 1 inch x 1 inch absorbent pad portion of a clear adhesive bandage. This was then applied to the appropriate treatment site to form a semi-occlusive patch.

Induction Phase:

Patches were applied 3 times weekly (e.g., Monday, Wednesday and Friday) for a total of 9 applications. Following supervised removal and scoring of the first induction patch, participants were instructed to remove all subsequent induction patches at home, twenty-four hours after application. Site evaluations were performed prior to re-application.

Challenge Phase:

Approximately 2 weeks after induction patch applications, a challenge patch was applied to a virgin (untreated) site adjacent to the original induction patch applications. The challenge patches were removed and the sites scored at the clinic 24 and 72 hours after applications.

Positive control substance(s):

no

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

53

Clinical observations:

No positive reactions for irritation or allergic contact sensitization.

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 53.0. Clinical observations: No positive reactions for irritation or allergic contact sensitization..

Reading:

2nd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

53

Clinical observations:

No positive reactions for irritation or allergic contact sensitizaiton.

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 72.0. Group: test group. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 53.0. Clinical observations: No positive reactions for irritation or allergic contact sensitizaiton..

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, HallBrite BHB did not indicate a potential for dermal irritation or allergic contact sensitization.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In a procedure essentially that of Draize (1955), a human Repeated Insult Patch Test (RIPT) was completed on 52 male and female volunteers. In an induction phase, approximately 0.2 mL aliquots of the undiluted test substance was applied 3 times weekly for a total of 9 applications to the upper backs between the scapulae using an absorbent pad and clear adhesive bandage. Pads were removed after 24 hours. Approximately 2 weeks following the induction phase, challenge patches were applied to untreated sites on the backs of volunteers and these removed and the sites scored after 24 and 72 hours. There were no positive skin reactions recorded in this study. In a similar RIPT study employing 53 male and female volunteers, 25% test substance in corn oil was used for induction and challenge phases of the study. As in the previous study, there were no positive skin responses recorded.

Skin sensitization studies were conducted on the test substance using the method of Magnusson and Kligman (OECD 406) at applied concentrations of 50 and 100%. The vehicle employed was 70% ethanol with a 5% concentration used for intradermal induction and a 100% topical induction concentration. Challenge concentrations were 50 and 100%. One of ten animals challenged at the 50% concentration exhibited a clear dermal response (score of 1 or greater) with all other animals showing responses less than 1. None of the animals challenged at 100% exhibited a dermal response. The test substance was not deemed a skin sensitizer under the conditions of this study. In essentially a repeat of this study, there were no positive skin responses in animals challenged at either 50 or 100%. In this latter study, a positive control group treated with the known skin sensitizer HCA gave a clear positive skin response.

Migrated from Short description of key information:

In two well conducted human Repeated Insult Patch Tests (RIPT) following accepted GLP standards, the test substance failed to cause skin sensitization at  applied challenge concentrations of either 25% or 100%.

Justification for selection of skin sensitisation endpoint:

In two well conducted human Repeated Insult Patch Tests (RIPT) following accepted GLP standards, the test substance failed to cause skin sensitization.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on consistent and negative findings from both human RIPT studies and guinea pig maximization studies, the subject material would not be rated for skin sensitization under either the EU Directive 67/548/EEC or under the EU CLP (Regulation (EC) 1272/2008).