Sodium methanethiolate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 April 1989 to 08 June 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

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

Details on test material:

Test article name : Sodium methylmercaptide
CAS RN: 5188-07-8
Origin: Atochem, Pilote UDL-AE no. 83562
Batch: 897016

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Iffa Crédo, 69210 L'Arbresle, France
- Age at study initiation: ca. 6 weeks
- Weight at study initiation: 180 +/- 12 g for males and 149 +/- 8 g for females
- Fasting period before study:
- Housing: 4 to 7 in polycarbonate cages
- Diet (ad libitum): UAR A04 C
- Water (e.g. ad libitum): filtered tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 50 +/-20
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

In a first assay, Sodium methylmercaptide (19.9% solution in water), was administered in its original form to a group of 10 Sprague-Dawley rats (5 males and 5 females) at a dose level of 2000 mg/kg at a volume of 2.05 ml/kg taking into consideration that the specific gravity (SG) of the test substance was 0.977. In a second assay, the test substance was administered at the dose levels of 400, 620, 950 and 1400 mg/kg to 4 groups of 5 males and at the dose levels of 620 and 950 mg/kg to 2 groups of 5 females. The test substance in aqueous solution was administered at a volume of 10 ml/kg. All animals were fasted before treatment.

Doses:

400, 620, 950, 1400 and 2000 mg/kg bw (of the 19.9% water solution)

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

The mortality, general behaviour and bodyweight gain of the animals were observed for a period of 14 days after the single administration of the test substance. A necropsy was performed on each animal found dead or sacrificed at the end of the study. 

Statistics:

The LD50 in males was calculated according to Finney's method.

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

116 mg/kg bw

Based on:

act. ingr.

95% CL:

75 - 161

Effect levels 2

Sex:

male/female

Dose descriptor:

LD50

Effect level:

581 mg/kg bw

Based on:

test mat.

95% CL:

376 - 810

Remarks on result:

other: 19.9% water solution

Mortality:

The mortality was respectively 20%, 40%, 100%, 100% and 100% at the dose levels of 400, 620, 950, 1400 and 2000 mg/kg in the males and 60%, 100% and 80 % at the dose levels of 620, 950 and 2000 mg/kg in the females. Mortality was recorded within minutes of treatment.

Clinical signs:

other: A significant decrease in spontaneous activity, dyspnea at the dose levels of 400 and 620 mg/kg, tonico-clonic convulsions at the dose levels of 950 and 1400 mg/kg before death of the rats, and ataxia and coma at the dose level of 2000 mg/kg were the main

Gross pathology:

An abnormal red colouration of the stomach was observed during the macroscopic examination of all animals from all dose levels found dead during the study. The necropsy performed on animals sacrificed at the end of the study revealed no macroscopic abnormalities.

Applicant's summary and conclusion

Interpretation of results:

toxic

Remarks:

Migrated information Category 3 Criteria used for interpretation of results: other: REGULATION (EC) No 1272-2008

Conclusions:

The LD50 of SODIUM METHYLMERCAPTIDE administered by oral route in the male Rat was 581 (376-810) mg/kg using the formulated test substance (19.9% in water) or 116 (75-161) mg/kg using the pure test substance. The test substance toxicity in the females was similar to that of the males.

Executive summary:

In a study conducted according to OECD Test Guideline 401, 5 male Sprague-Dawley rats/dose were given sodium methanethiolate via oral gavage (supplied as a 19.9% solution in water; diluted further in water and dosed at 10 ml/kg except for the high dose (which was administered at 2.05 ml/kg of the 19.9% solution); the doses were equivalent to 400, 620, 950, 1400 and 2000 mg/kg bw of the 19.9% solution or 80, 123, 189, 279, and 398 mg active ingredient (a.i.)/kg bw. Five female rats/group were dosed at 620, 950 and 2000 mg/kg bw (equivalent to 123, 189 and 398 mg a.i./kg bw). Animals were observed for 14 days after dosing. Mortality in the males was 1/5 and 2/5 at 400 and 620 mg/kg bw, respectively, and 5/5 at higher doses. Mortality was recorded within minutes of dosing. The mortality in the females was 3/5, 5/5, and 4/5 at 620, 950, and 2000 mg/kg bw, respectively. In males, a significant decrease in spontaneous activity and dyspnea at 400 and 620 mg/kg bw, tonic-clonic convulsions at the dose levels of 950 and 1400 mg/kg bw before death of the rats, and ataxia and coma at 2000 mg/kg bw were the main clinical signs recorded. Also in males, abnormal red coloration of the stomach was observed during the macroscopic examination of all animals from all dose levels found dead during the study. The necropsy performed on animals sacrificed at the end of the study revealed no macroscopic abnormalities. The toxicity in the females was similar to that of the males. The LD50 of the formulation (19.9% sodium methanethiolate solution) was 581 mg/kg bw, equivalent to 116 mg a.i./kg bw.