Registration Dossier

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:
other: The study is classified as reliable with restrictions because this is an older study but sufficient detail is provided to assess the acute oral toxicity of t-butyl mercaptan.

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

Reference
Name:
Unnamed
Type:
Constituent
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 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:
no data
Body weight:
no data
Gross pathology:
no data
Other findings:
no data

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: other: REGULATION (EC) No 1272/2008 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 December 2008
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 EC Regulation 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.