Potassium mercaptoacetate

Exposure related observations in humans: other data

Administrative data

Endpoint:

exposure-related observations in humans: other data

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Adopted according to OECD SIDS

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Type of study / information:

Human skin irritation and sensitization

Endpoint addressed:

skin irritation / corrosion

skin sensitisation

Principles of method if other than guideline:

Repeated insult patch tests

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Ammonium mercaptoacetate

EC Number:

226-540-9

EC Name:

Ammonium mercaptoacetate

Cas Number:

5421-46-5

Molecular formula:

C2H4O2S.H3N

IUPAC Name:

ammonium sulfanylacetate

Details on test material:

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

Method

Details on study design:

Repeated insult patch tests were used to evaluate the skin irritation and sensitization potential of 14.4% Ammonium Thioglycolate in a total of 240 subjects (32 males, 208 females, 18-69 years old). A panel of 240 subjects was patch tested with 14.4% Ammonium Thioglycolate. On Mondays, Wednesdays, and Fridays, the test substance was applied (0.2 ml, semi-occlusive patch) for 24 h to an area, between the scapulae and waist, adjacent to the midline. New sites were used for subsequent induction patch applications.

Patch removals on Tuesday and Thursday were each followed by a 24 h non-treatment period, and removals on Saturday by a 48 h non-treatment period. Each site was scored prior to application of the next patch according to the scale: 0 (no evidence of any effect) to 4 (severe, defined as deep-red erythema with/without vesiculation or weeping). The test procedure was repeated for a total of nine applications.

After a 15 to 19 day nontreatment period, challenge patches were applied to new test sites. Reactions were scored at 24 and 48 h post-application. Any subject with a reaction during the challenge phase that was stronger than mild erythema (score = 1) was rechallenged 28 days later at a new test site.

Exposure assessment:

not specified

Results and discussion

Results:

A total of 20 subjects withdrew from the study, during induction phase, for reasons that were unrelated to treatment. Four of the subjects who withdrew had reactions to 14.4% Ammonium Thioglycolate: barely perceptible erythema (2 subjects), mild erythema with mild oedema (1 subject), and moderate erythema (1 subject). Of the 220 subjects who completed the study, 4 were not available for 24 h challenge readings.

In these subjects, reactions were not observed during 48 h challenge readings nor during the induction phase. Twelve of the 220 subjects had reactions to 14.4% Ammonium Thioglycolate only during the induction phase. Reactions classified as barely perceptible erythema score = +) predominated. Stronger reactions were observed in 3 subjects: 1 subject with mild erythema (score = 1) and 2 subjects with moderate erythema (score = 2). Reactions to not more than two induction applications were observed. Seven subjects had reactions to 14.4% Ammonium Thioglycolate only during the challenge phase. Reactions classified as barely perceptible erythema predominated. A stronger reaction, moderate erythema with mild oedema (score = 2e; 48 h reading), was observed in 1 subject. Reactions were not observed after the second challenge.

Applicant's summary and conclusion

Conclusions:

The authors concluded that 14.4% Ammonium Thioglycolate did not induce clinically meaningful irritation or any evidence of induced allergic contact dermatitis in human subject.