Propyl 3,4,5-trihydroxybenzoate

Sensitisation data (human)

Administrative data

Endpoint:

sensitisation data (humans)

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Positive rates to propyl gallate on patch testing: a change in trend

Author:

Perez A. et al.

Year:

2008

Bibliographic source:

Contact Dermatitis, 58(1), 47-48

Materials and methods

Type of sensitisation studied:

skin

Study type:

study with volunteers

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: To assess the prevalence of allergic contact dermatitis to propyl gallate via patch test
- Short description of test conditions: From 1988 to 2005, 9529 patients were patch tested to the face series, 6973 were females and 2556 were males. Patch tests were read at 2 D and 4 D.
- Parameters analysed / observed: Scoring of positive reactions (negative, +, ++ and +++)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Propyl 3,4,5-trihydroxybenzoate

EC Number:

204-498-2

EC Name:

Propyl 3,4,5-trihydroxybenzoate

Cas Number:

121-79-9

Molecular formula:

C10H12O5

IUPAC Name:

propyl 3,4,5-trihydroxybenzoate

Specific details on test material used for the study:

Propyl gallate was used at a 1% petrolatum (pet.).

Method

Type of population:

general

Ethical approval:

not specified

Subjects:

- Number of subjects exposed: 9529 (6973 females and 2556 males)
- Sex: males & females

Clinical history:

not specified

Controls:

not specified

Route of administration:

dermal

Details on study design:

TYPE OF TEST(S) USED: patch test (epicutaneous test)

ADMINISTRATION
- Type of application: occlusive / semiocclusive /other: not specified
- Description of patch: Finn Chambers are used and mounted on Scanpor tape.
- Vehicle / solvent: Propyl gallate was used at a 1% petrolatum (pet.)
- Testing/scoring schedule: Patch tests were read at 2 D and 4 D.

EXAMINATIONS
- Grading/Scoring system: Positive reactions were scored as per International Contact Dermatitis Research Group recommendations as negative, +, ++, and +++ reactions
- Statistical analysis: Chi-square test

Results and discussion

Results of examinations:

SYMPTOMS
- Frequency, level, duration of symptoms observed: not specified

NO. OF PERSONS WITH/OUT REACTIONS COMPARED TO STUDY POPULATION
- Number of subjects with positive reactions: 55 patients (0.57%), 46 were female (0.65%) and 9 were male (0.33%).
- Number of subjects with negative reactions: 9474 patients
- Number of subjects with equivocal reactions: not specified
- Number of subjects with irritating reactions: not specified

RESULT OF CASE REPORT: There was a significant difference (P < 0.05) in the positivity rates between the 1988-96 period (0.45%) and the 1997-2005 period (0.77%). A review of face series performed in the last 18 years has shown a statistically significant increase in propyl gallate-positive rates on patch testing over the last decade. An increase in its use in the cosmetic industry may well be the explanation for this.

Any other information on results incl. tables

The authors assumed that an increase in its use in the cosmetic industry may well be the explanation for the significant increase in propyl gallate-positive rates on patch testing over the last decade. Furthermore, a concomitant reduction of propyl gallate as an antioxidant in food, with oral tolerance being less likely to develop, may also be a contributing factor in the increasing trend of allergic contact dermatitis caused by propyl gallate.

Applicant's summary and conclusion

Conclusions:

In a human patch test reported by Perez et al. (2008), positive reactions were observed in 0.57% of the patients (55 out of 9529 patients). There was a significant difference (P < 0.05) in the positivity rates between the 1988-96 period (0.45%) and the 1997-2005 period (0.77%). Furthermore, a statistically significant increase in propyl gallate-positive rates on patch testing over the last decade was observed. The authors assumed that an increase in its use in the cosmetic industry may well be the explanation for this. Also, a concomitant reduction of propyl gallate as an antioxidant in food, with oral tolerance being less likely to develop, may also be a contributing factor in the increasing trend of allergic contact dermatitis caused by propyl gallate.

Executive summary:

In a human patch test reported by Perez et al. (2008), the prevalence of allergic contact dermatitis to propyl gallate was investigated in 9529 patients (6973 females and 2556 males) from 1988 to 2005. Patch tests were read at 2 D and 4 D. Positive reactions were scored as per International Contact Dermatitis Research Group recommendations as negative, +, ++, and +++ reactions. Propyl gallate was used at a 1% petrolatum (pet.). Out of 9529 patients, a total of 55 patients (0.57%) had positive reactions to propyl gallate, which 46 of them were females (0.65%) and 9 were males (0.33%). There was also a significant difference in the positivity rates between the 1988-96 period (0.45%) and the 1997-2005 period (0.77%). A review of face series performed in the last 18 years has shown a statistically significant increase in propyl gallate-positive rates on patch testing over the last decade. An increase in its use in the cosmetic industry may well be the explanation for this. Nevertheless, a concomitant reduction of propyl gallate as an antioxidant in food, with oral tolerance being less likely to develop, may also be a contributing factor in the increasing trend of allergic contact dermatitis caused by propyl gallate.