2,2'-[1,2-ethanediylbis(oxy)]bis(ethanethiol)

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Start of experimental phase: 05 July 2016 End of experimental phase: 20 July 2016 Study completion: 08 August 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted on 24 February 1987

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-[1,2-ethanediylbis(oxy)]bis(ethanethiol)

EC Number:

239-044-2

EC Name:

2,2'-[1,2-ethanediylbis(oxy)]bis(ethanethiol)

Cas Number:

14970-87-7

Molecular formula:

C6H14O2S2

IUPAC Name:

2,2'-[1,2-ethanediylbis(oxy)]bis(ethanethiol)

Test material form:

liquid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
Species and strain: Rat, Hsd: Sprague Dawley SD
Sex: Males and females (nulliparous and non-pregnant)
Age: 6 to 8 weeks old
Weight at order: 176 to 200 grams
Supplier: Envigo RMS s.r.l., San Pietro al Natisone (UD), Italy
Breeder: Envigo RMS s.r.l., San Pietro al Natisone (UD), Italy
Date of arrival: 23 June 2016
Weight range at arrival: 175-182 grams
Acclimatisation period: At least 5 days
Veterinary health check: During acclimatisation period

ENVIRONMENTAL CONDITIONS
Animals per cage: Up to 5 of one sex during acclimatisation; individually caged during the study
Housing: Clear polysulphone H-Temp solid bottomed cages (Tecniplast Gazzada S.a.r.l., Buguggiate, VA, Italy) measuring 59.5×38×20 cm during
acclimatisation period and 42.5×26.6×18.5 cm during the study with nesting material provided into suitable bedding bags.
Cage control: Daily inspected and changed as necessary (at least 3 times/week)
Water Drinking: water supplied to each cage via a water bottle
Water supply: Ad libitum
Diet: 4 RF 18 (Mucedola S.r.l., Via G. Galilei, 4, 20019, Settimo Milanese (MI) Italy)
Diet supply: Ad libitum throughout the study
Room lighting: Artificial (fluorescent tubes), daily light/dark cycle of 12/12 hours
Air changes: Approximately 15 to 20 air changes per hour
Temperature range: 22 °C±2 °C
Relative humidity range: 55%±15%

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: Dorsal surface of the trunk
- % coverage: Approximately 10% of body surface
- Type of wrap if used: Adhesive bandage and gauze patch

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes, with cotton wool soaked with lukewarmwater.
- Time after start of exposure: 24 hours

Duration of exposure:

The animals remained in contact with the test item for 24 hours.

Doses:

2000 mg/kg

No. of animals per sex per dose:

5

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed for clinical signs the day of dosing: on dosing, approximately 1 hour after dosing, 2 hours
after dosing and 4 hours after dosing, daily thereafter. All animals were weighed at allocation to the study (Day -1), on the day of dosing (Day 1) and
on Days 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD0

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Mortality:

No mortality occurred.

Clinical signs:

No clinical signs were observed in male or female animals after treatment during the observation period.

Body weight:

Body weights and body weight changes were within the expected range for this species and age of animals at the end of the study.

Gross pathology:

No abnormalities were found at necropsy examination performed on all animals at termination of the study.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The acute toxicity of the test item was investigated following dermal administration of a single dose to the rat at 2000mg/kg.
No mortality occurred following dosing and no signs of toxicity were observed.
These results indicate that the test item has no toxic effect on the rat following dermal exposure over a 24 hour period at a level of 2000mg/kg.
The lack of mortality demonstrates the Lethal Dose to be greater than 2000mg/kg.

Executive summary:

The acute toxicity of Dimercapto-1,8-dioxa-3,6-octane (DMDO) was investigated following dermal administration of a single dose to the rat. A single dose of 2000 mg/kg was administered to a group of 5 male and 5 female animals for 24 hours. After 14 days, all animals were killed and subjected to necropsy examination. No mortality occurred and no signs of toxicity were observed in male or female animals during the observation period. The body weight changes observed during the study were within the expected range for this species and age of animals. No significant abnormalities were found at necropsy in the animals at termination of the study. No abnormalities were observed at the treated site. These results indicate that the test item has no toxic effect on the rat following dermal exposure over a 24 hour period at a level of 2000 mg/kg. The lack of mortality demonstrates the Lethal Dose to be greater than 2000 mg/kg.