3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate

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:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Documentation is insufficient for assessment. Few details on the study protocol are given.

Data source

Reference

Reference Type:

publication

Title:

New cosmetic allergens: isononyl isononanoate and trioleyl phosphate

Author:

Goossens, A. et al.

Year:

2008

Bibliographic source:

Contact Dermatitis, 2008; 59: 320-321

Materials and methods

Study type:

clinical case study

Endpoint addressed:

other: allergenic contact dermatitis

Principles of method if other than guideline:

A woman with a history of allergic contact dermatitis reacted to application of a lipstick. Patch testing was performed according to International Contact Dermatitis Research Group criteria, using the ingredients in the lipstick. The skin sensitisation score was assessed on day 2 and 4 after patch testing. Volunteers were patch tested with the substances that the woman reacted to, as a negative control.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate

EC Number:

261-665-2

EC Name:

3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate

Cas Number:

59219-71-5

Molecular formula:

C18H36O2

IUPAC Name:

3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate

Details on test material:

- Name of test material (as cited in study report): isononyl isonoanoate
- Analytical purity: no data

Method

Type of population:

other: case report

Subjects:

- Number of subjects exposed: 1 (case report); 20 (control subjects)
- Sex: female (case report)
- Age: 40 (case report)

Ethical approval:

not applicable

Route of exposure:

dermal

Reason of exposure:

intentional

Exposure assessment:

not specified

Details on exposure:

A 40-year old non-atopic woman with a history of reaction to an 'anticellulite' cream (Roc Retinol Body Contouring Triple Action Creme, Johnson & Johnson, Issy-les-Moulineaux, France) presented in 2002 with contact chelitis following application of Rouge Novalip lipstick (La Roche Posay, France). Patch testing with the European baseline series (Trolab: Hermal, Reinbek, Germany) and a cosmetics series were performed with negative response. Patch testing with Rouge Novalip (two colours) and the Roc Retinol Body Contouring Triple Action Creme caused a positive result. Details of the patch test method was not provided.
In September 2007 the patient presented with severe allergic contact dermatitis on the eyelids following the application of lipstick to the eyelids (Rouge Novalip, La Roche-Posay, France). Patch testing with the individual ingredients of the lipstick was conducted; resulting in reactions to isononyl isononanoate, trioleyl phosphate and oleyl erucate. No details of the study protocol were provided.
Additional patch testing with the lipstick ingredients was performed in November 2007. Van der Bend patch test chambers were attached with Micropore and fixed in place with Mefix adhesive tape. The results were scored according to the International Contact Dermatitis Research Group criteria on Day 2, 4 and 7. The results showed strong vesicular positive reactions to all tested ethanolic dilutions of isononanoate tested on the forearm, from20% (which is the actual use concentration in the product) to 1%. On Day 7, the patient developed severe oedema of the whole test area. The 5% preparation in petrolatum gave a negative result. There was a positive reaction to trioleyl phosphate 1% and 5% in petrolatum. The positive result to oleyl erucate (20% in petrolatum) observed in September 2007 could not be reproduced.
In June 2008, patch tests using the same methods were performed with analogues, to assess the possiblility of cross-reactions. No positive reactions were observed with cetearyl ethylhexanoate (1, 2.5, 5, 10% in ethanol), cetearyl isononanoate (1, 2.5, 5, 10% in pet.), cetyl phosphate (1, 2.5, 5, 10% in pet.), diisopropyl adipate (20% in ethanol), isodecyl neopentanoate (1, 2.5, 5, 10% in ethanol), octyldodecyl neopentanoate (1, 2.5, 5, 10% in ethanol), oleyl erucate (20% on pet.), and stearyl ethylhexanoate and cetyl hexanoate (5% in pet.). Subsequent testing with isononyl isononanoate (5% ethanol) and trioleyl phosphate (1% in pet.) in 20 control subjects gave a negative result.

Results and discussion

Clinical signs:

Results of patch testing:
- September 2007: Positive reactions to isononyl isononanoate, trioleyl phosphate (Day 7 only) and oleyl erucate (Day 7 only) were reported.
- November 2007: The results showed strong vesicular positive reactions to all tested ethanolic dilutions of isononanoate tested on the forearm, from20% (which is the actual use concentration in the product) to 1%. On day 7, the patient developed severe oedema of the whole test area. The 5% preparation in petrolatum gave a negative result. There was a positive reaction to trioleyl phosphate 1% and 5% in petrolatum. The positive result to oleyl erucate (20% in petrolatum) observed in September 2007 could not be reproduced.
- June 2008: No positive reactions were observed with cetearyl ethylhexanoate (1, 2.5, 5, 10% in ethanol), cetearyl isononanoate (1, 2.5, 5, 10% in pet.), cetyl phosphate (1, 2.5, 5, 10% in pet.), diisopropyl adipate (20% in ethanol), isodecyl neopentanoate (1, 2.5, 5, 10% in ethanol), octyldodecyl neopentanoate (1, 2.5, 5, 10% in ethanol), oleyl erucate (20% on pet.), and stearyl ethylhexanoate and cetyl hexanoate (5% in pet.). Subsequent testing with isononyl isononanoate (5% ethanol) and trioleyl phosphate (1% in pet.) in 20 control subjects gave a negative result.