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Diss Factsheets

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature

Data source

Referenceopen allclose all

Reference Type:
review article or handbook
Title:
SIDS Dossier
Author:
OECD
Year:
2008
Bibliographic source:
OECD SIDS Dossier - sodium methanethiolate
Reference Type:
other: Unpublished study report
Title:
Acute dermal toxicity in rats. CIT Report No. 10874.
Author:
Elf Atochem
Year:
1994
Bibliographic source:
as cited in Methanethiol/sodium methanethiolate, OECD SIDS Initial Assessment Report For SIAM 27, 2008

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Version / remarks:
adopted 1987
GLP compliance:
yes
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Sodium methanethiolate
EC Number:
225-969-9
EC Name:
Sodium methanethiolate
Cas Number:
5188-07-8
Molecular formula:
CH4S.Na
IUPAC Name:
sodium methylsulfanide
Test material form:
liquid
Specific details on test material used for the study:
- Test article name : Sodium methylmercaptide
- CAS No.: 5188-07-8
- Origin: Elf Aquitaine, Lacq
- Batch: 93-7074
- Composition: Sodium methylmercaptide: 21.2 % (w/w) in water, free NaOH: 1.0% (w/w)

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
water
Duration of exposure:
24 hours
Doses:
First assay: 2000 mg/kg bw (424 mg/kg bw raw material)
Second assay: 400 mg/kg bw (84.8 mg/kg bw raw material)
No. of animals per sex per dose:
At 2000 mg/kg bw: 1 per sex
At 400 mg/kg bw: 4 per sex
Control animals:
no
Details on study design:
Sodium methylmercaptide (21.2% solution in water) was administered by dermal route to a group of Sprague-Dawley rats. As the test substance was anticipated to be corrosive, 1 animal per sex were used in a first assay. The test substance in its original form was applied directly to the skin at a dose of 2000 mg/kg bw (i.e. 424 mg/kg bw in raw material), taking into consideration that the specific gravity (SG) of the test substance was 1.12. In a second assay, 8 animals (4 males and 4 females) were treated with the test substance at a dose of 400 mg/kg bw (i.e. 84.8 mg/kg in raw material). After 24 hours under a semi-occlusive dressing, no residual test substance was observed on removal of the dressing. The animals given 400 mg/kg bw were checked for clinical signs, mortality and body weight gain for a period of 14 days following the single application of the test substance. A necropsy was performed on each animal sacrificed during the study or sacrificed at the end of the study.
Statistics:
not specified

Results and discussion

Effect levelsopen allclose all
Key result
Sex:
male/female
Dose descriptor:
LD0
Effect level:
> 84.8 mg/kg bw
Based on:
test mat.
Remarks on result:
other: recalculated to 100% raw material
Sex:
male/female
Dose descriptor:
LD0
Effect level:
> 400 mg/kg bw
Based on:
test mat.
Remarks on result:
other:
Remarks:
formulated test substance: 21.2% in water
Mortality:
At 2000 mg/kg bw (424 mg/kg bw raw material) the 2 treated animals were sacrificed on day 2 for humane reasons. At 400 mg/kg (84.8 mg/kg bw raw material) bw no deaths were noted.
Clinical signs:
At 2000 mg/kg bw tissue lesions on the whole depth of the skin were noted after removal of the dressing on day 2. At 400 mg/kg bw no cutaneous reactions were noted in males and females. Hypoactivity, tremors were noted in one female. No clinical signs and no alteration of the general behaviour were noted in the other animals.
Body weight:
At 400 mg/kg bw reversible body weight loss between days 1 and 5 was noted in one female.
Gross pathology:
n.a.
Other findings:
n.a.

Applicant's summary and conclusion

Interpretation of results:
study cannot be used for classification
Conclusions:
Based on the results from an acute dermal toxicity study, the dermal LD0 value was determined to be > 84.8 mg/kg bw.
Executive summary:

In an acute dermal toxicity study (OECD 402), Sprague-Dawley rats (1/sex) were applied a single dermal dose of 2000 mg/kg bw of Sodium methanethiolate (21.2% solution in water, equalling 424 mg/kg bw raw material). In addition, eight animals (4/sex) were treated with a single dermal dose of 400 mg/kg (i.e. 84.8 mg/kg bw raw material). After treatment the animals were observed for 14 days. At 2000 mg/kg bw, tissue lesions on the whole depth of the skin were noted after removal of the dressing on day 2. The two treated animals were sacrificed on day 2 for humane reasons. At 400 mg/kg bw, no cutaneous reactions and no deaths were noted. Hypoactivity, tremors and reversible body weight loss between days 1 and 5 were noted in one female. No clinical signs and no alteration of the general behaviour were noted in the other animals.

Based on the results, the dermal LD0 was determined to be > 400 mg/kg bw and after recalculation towards the pure substance, the dermal LD0 can be considered to be > 84.8 mg/kg bw.