Mercaptoacetic acid

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key 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:

study report

Title:

Unnamed

Year:

1973

Report date:

1973

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

2 animals per dose levels

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Mercaptoacetic acid

EC Number:

200-677-4

EC Name:

Mercaptoacetic acid

Cas Number:

68-11-1

Molecular formula:

C2H4O2S

IUPAC Name:

2-sulfanylacetic acid

Details on test material:

Test compound: Thioglycolic acid
CAS no.: 68-11-1
Source: Evans Chemetics Inc.
Batch: ba-93B-109
Purity: 98.2%

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

No data

Administration / exposure

Type of coverage:

occlusive

Vehicle:

water

Details on dermal exposure:

Twenty-four hours prior to applying the test materials, the entire trunk  of the rabbits to be used were clipped free of hair with electric  clippers. The test materials were applied under a heavy gauge plastic  cuff. The cuff was held in place with rubber bands and covered with a  cloth bandage which was taped securely to the marginal hair. Thioglycolic  acid was applied as a solution in water.

Duration of exposure:

24 hours

Doses:

252, 500, 1000 or 2000 mg/kg

No. of animals per sex per dose:

2

Control animals:

no

Details on study design:

After application of the test material, the animals were placed in  individual holding cages with free access to food and water. At the end  of the 24-hour exposure period, the cuffs were removed and the skin was  washed with soap and water, rinsed thoroughly, and dried with a towel.  The animals were observed for signs of toxicity during the exposure and  periodically for two weeks or more thereafter. Body weights were recorded  before and after the exposure period and at intervals up to two-weeks  post-application or until the pre-exposure body weights were surpassed.

Statistics:

no data

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

848 mg/kg bw

Based on:

test mat.

95% CL:

505 - 1 430

Mortality:

Dose        # dead/# treated        Time of Death 
250         0/4                        --- 
500         1/4                        Day 1
1000         2/4                         Day 1, 1
2000         4/4                        Day 1, 1, 1, 1

Clinical signs:

other: Topical effects noted after removal of the cuff were slight to moderate  erythema, slight to moderate oedema and slight to moderate necrosis in  all cases (no other clinical signs were reported). 

Gross pathology:

no data

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Executive summary:

In a non-guideline acute dermal toxicity study, 4 groups of 2 New Zealand whiterabbits per sex were dosed with 250, 500, 1000 or 2000 mg/kg bw thioglycolic acid (purity 98.2%). Animals were observed for 14 days following the exposure for mortality and clinical signs. Mortality was 0/4, 1/4, 2/4 and 4/4 on day one. No other effects than a skin irritation at the site of application was reported. The LD₅₀was 848 mg/kg bw.