Salicylic acid

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:

supporting study

Study period:

data not available

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The method and the test conditions are sufficiently described to assess the results. The quantity of salicylic acid applied is unknown.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Relationship of pKa and acute skin irritation in humans.

Author:

Berner B, Wilson DR, Mazzenga GC et al

Year:

1989

Bibliographic source:

J. Toxicol. - Cut. & Ocular Toxicol., 9(2), 481-492.

Materials and methods

Study type:

study with volunteers

Endpoint addressed:

skin irritation / corrosion

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Test substance was applied on day 1 on the back of woman. On day 2 the patches were removed and erythema and edema were scored by standard 0-4 visual scales. On day 3 the procedure of day 2 was repeated.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Salicylic acid

EC Number:

200-712-3

EC Name:

Salicylic acid

Cas Number:

69-72-7

Molecular formula:

C7H6O3

IUPAC Name:

2-hydroxybenzoic acid

Details on test material:

- Name of test material (as cited in study report): salicylic acid (Fisher, Springfield, NJ)
no other data

Method

Type of population:

general

Subjects:

- Number of subjects exposed: 16
- Sex: female
- Age: 35 to 45
- Race: 10 were hispanic origin with various degrees of olive-complected skin. 5 were white with type II skin, and one was a white/Polynesian mixture with a slightly olive skin tone.
- other: All subjects had reasonably clear backs with no or few comedones, moles, or freeckles.

Ethical approval:

not specified

Route of exposure:

dermal

Reason of exposure:

intentional

Exposure assessment:

estimated

Details on exposure:

Sixteen female subjects (with reasonable clear backs) ranging from 35 to 45 years of age consented to the study.
The scapular regions of the upper back unoccluded by undergarments were tested. Baseline scoring and measurements were taken. The relative humidity and temperature were noted. The loaded test discs were applied to the skin occluded with 3% ethylene vinyl acetate membrane and secured with tape. On day 2, the patches were removed and the measurement was repeated. Erythema and edema were scored by standard 0-4 visual scale by Draize, with an additional scale at 0.5 to signify borderline reaction. Blow flow and color were measured too.
On day 3, procedure of day 2 was repeated. Primary irritation index was calculated as the average for the 2 time points of the sum of the erythema and edema scores.

Examinations:

- Other: skin irritation was evaluated.

Medical treatment:

None

Results and discussion

Clinical signs:

No data

Results of examinations:

Mean scores for salicylic acid were:
24hr erythema 1.0 +/- 0.9; edema 0.8 +/- 0.9
48hr erythema 0.7 +/- 0.8; edema 0.6 +/- 0.8

Control = water
24hr erythema 0.03 +/- 0.18; edema 0.03 +/- 0.18
48hr erythema 0.06 +/- 0.21; edema 0.00

Effectivity of medical treatment:

not applicable

Outcome of incidence:

not applicable

Applicant's summary and conclusion

Conclusions:

Under the conditions of this test, salicylic acid is slightly irritant.

Executive summary:

In a pKa and human skin irritation (Berner et al., 1989/90), a skin irritation study with human volunteers was performed. Sixteen woman ranging from 35 to 45 years of age consented to the study. Ten were of Hispanic origin with various degrees of olive-complected skin. Five were white type II skin, and one was a white/Polynesian mixture with a slightly olive skin tone. All subjects had reasonably clear backs with no or few comedones, moles, or freckles. On day 1 the subjects acclimated for a half hour during which time the sites was marked on the back with a felt tip marker. The scapular regions of the upper back unoccluded by undergarnents were tested. Two replicates per subject and a distilled water control were performed. Baseline scoring and measurements were taken. The relative humidity and temperature were noted. The loaded test discs were applied to the skin occluded with 3 % ethylene vinyl acetate membrane and secured with tape. On day 2 the patches were removed and the sites marked again. Thirty minutes later, the measurements were repeated. Erythema and edema were scored by standard 0 -4 visual scales, with an additional scale at 0.5 to signify borderline reaction. Blood flow assessed by laser Doppler velocimetry and color were measured. On day 3 the procedure of day 2 was repeated. Erythema and Edema scores at 24h were 1.0 +/-0.9 and 0.8 +/- 0.9 respectively. Erythema and Edema scores at 48h were 0.7 +/- 0.8 and 0.6 +/- 0.8 respectively. Under the conditions of this test, salicylic acid showed a slight irritant effect.