2-methylpropane-2-thiol

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Toxicologic studies on organic sulfur compounds. 1. Acute toxicity of some aliphatic and aromatic thiols

Author:

Fairchild EJ and Stokinger HE

Year:

1958

Bibliographic source:

Am. Ind. Hyg. J., 19, 171-189

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Doses were administered by oral gavage and the test substance was undiluted. The animals were observed for 14 days after dose administration. Tissues samples were submitted for pathologic examination after having first been examined grossly and preserved.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-methylpropane-2-thiol (CAS # 75-66-1)

IUPAC Name:

2-methylpropane-2-thiol (CAS # 75-66-1)

Details on test material:

Test substance: t-butyl mercaptan (2-methylpropane-2-thiol)
CAS 75-66-1
Purity: "essentially pure substance"

Test animals

Species:

rat

Strain:

Wistar

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: local commercial breeder
- Age at study initiation: no data
- Weight at study initiation: 200 +/- 20 g
- Fasting period before study: no data
- Housing: no data
- Diet (e.g. ad libitum): Rockland Rat Diet
- Water (e.g. ad libitum): tap water
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

Doses were administered by oral gavage and the test substance was undiluted.

Doses:

1672, 3344, 6688, and 13375 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

The animals were observed for 14 days after dose administration. Tissues samples were submitted for pathologic examination after having first been examined grossly and preserved.

Statistics:

The LD50 was calculated by the method of Weil.

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LD50

Effect level:

4 729 mg/kg bw

95% CL:

3 756 - 5 954

Mortality:

1672 mg/kg - no deaths
3344 mg/kg - no deaths
6688 mg/kg - 5/5 dead, 4 dead by 12 hours, additional death at 32 hours
13376 - 5/5 dead by 20 hours

Clinical signs:

other: other: no data

Gross pathology:

no data

Other findings:

no data

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The LD50 was 4729 mg/kg bw.

Executive summary:

In an acute oral toxicity study (pre-guideline study), Male rats (5/dose; Wistar) were dosed with 2 -methylpropane-2 -thiol (CAS Number 75 -66 -1) at doses of 1672, 3344, 6688, and 13375 mg/kg bw and observed for 14 days. 

Mortality was 0, 0, 5, and 5 of the 5 animals per group, respectively. No other data (e.g. signs of toxicity) were reported. The LD₅₀ was 4729 mg/kg bw. The substance is not classified according to Regulation (EC) No 1272/2008.

This study received a Klimisch Score of 2 and was classified as reliable with restrictions because it is an older study but there was sufficient detail provided to assess the acute oral toxicity of 2 -methylpropane-2-thiol.