Ethyl methyl sulphide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 15-NOV-1993 to 03-MAR-1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study similar to OECD testing guideline and performed according to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl methyl sulphide

EC Number:

210-868-4

EC Name:

Ethyl methyl sulphide

Cas Number:

624-89-5

Molecular formula:

C3H8S

IUPAC Name:

(methylsulfanyl)ethane

Details on test material:

- Name of test material (as cited in study report): methyl ethyl sulfide
- Molecular formula (if other than submission substance): C3H8S
- Molecular weight (if other than submission substance): 76.16 g
- Smiles notation (if other than submission substance): C(SC)C
- InChl (if other than submission substance): InChI=1/C3H8S/c1-3-4-2/h3H2,1-2H3
- Substance type: pure active substance
- Physical state: clear colorless liquid
- Stability under test conditions: data not available
- Storage condition of test material: room temperature, protected from light

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Mohican Valley Rabbitry, Loudonville, Ohio
- Age at study initiation: adults
- Weight at study initiation: 1.924 to 2.130 kg for males and 2.286 to 2.582 kg for females
- Housing: individually in suspended stainless steel cages
- Diet: Purina Certified Rabbit chow #5322, ad libitum
- Water: municipal tap water treated by reverse osmosis or deionization, ad libitum
- Acclimation period: for a minimum of 5 days


ENVIRONMENTAL CONDITIONS
- Temperature: 65 to 70°F (#18.3 to 21.1°C)
- Humidity: 33 to 49%
- Air changes: 10 to 12 air changes per hour
- Photoperiod: 12 hrs dark / 12 hrs light


IN-LIFE DATES: From 18-NOV-1993 to 02-DEC-1993

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: unexposed area served as control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.5 mL
- Concentration: undiluted

Duration of treatment / exposure:

4 hours

Observation period:

up to 14 days

Number of animals:

6 (3 males and 3 females)

Details on study design:

TEST SITE
- Area of exposure: approximately 1 inch x 1 inch (# 2.54 cm x 2.54 cm)
- % coverage: data not available
- Type of wrap if used: the test article was administrated under the gauze patch. The gauze patch was held in contact with the skin at the cut edges with a non-irritating tape. Removal and ingestion of the test article was prevented by placing an elastic wrap over the trunk and test area (semi-occlusive binding). The elastic wrap was then further secured with adhesive tape around the trunk at the cranial and caudal ends.


REMOVAL OF TEST SUBSTANCE
- Washing: residual test article was removed using gauze moistened with distilled water.
- Time after start of exposure: 4 hours


SCORING SYSTEM: Draize

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24, 48, 72 hours

Score:

1.5

Max. score:

4

Reversibility:

fully reversible within: day 7 to day 14

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24, 48, 72 hours

Score:

1.85

Max. score:

4

Reversibility:

fully reversible within: day 7 to day 10

Irritant / corrosive response data:

Exposure to the test article produced well-defined erythema and very slight to moderate edema on 6/6 test sites at the 1 hour scoring interval. The dermal irritation generally diminished during the remainder of the test period and resolved completely in all animals by study day 14. Additional dermal findings noted during the period included irritation observed in taped area outside the test site and desquamation, which were noted on 6/6 and 5/6 test sites, respectively.

Any other information on results incl. tables

Table 1: Irritant/corrosive response data for each animal at each observation time up to removal of each animal from the test

Score at time point / Reversibility	Erythema	Edema
	Max. score: 4	Max. score: 4
60 min	2/2/2/2/2/2	2/2/2/1/3/2
24 h	2/2/2/2/3/2	2/2/2/2/3/2
48 h	1/2/1/1/2/1	2/2/2/2/2/2
72 h	1/1/1/1/1/1	1/1/2/1/1/2
Average 24h, 48h, 72h	1.3/1.7/1.3/1.3/2/1.3 Mean score: 1.5	1.7/1.7/2/1.7/2/2 Mean score: 1.85
Day 7	0/1/1/0/1/1	0/0/1/0/0/1
Day 10	-/0/0/-/0/1	-/0/0/-/0/0
Day 14	-/-/-/-/-/0	-/-/-/-/-/0
Reversibility*)	c	c
Average time (unit) for reversion	Day 7 to Day 14	Day 7 to Day 10

 *) Reversibility: c. = completely reversible; = not completely reversible; n. = not reversible

Applicant's summary and conclusion

Interpretation of results:

Category 3 (mild irritant)

Conclusions:

Methyl Ethyl Sulfide is considered to be a slight irritant to the skin of the rabbit.

Executive summary:

The potential irritant and/or corrosive effects of Methyl Ethyl Sulfide were evaluated on New Zealand White rabbits (study similar to OECD testing guideline and according to GLP). Each of six rabbits received a 0.5 ml dose of the test article as a single dermal application. The dose was held in contact with the skin under a semi-occlusive binder for an exposure period of four hours. Following the exposure period, the binder was removed and the remaining test article was wiped from the skin using gauze moistened with distilled water. Test sites were subsequently examined and scored for dermal irritation for up to 14 days following patch removal.

The mean scores at 24, 48 and 72 hours were:

- for erythema: mean score = 1.5

- for edema: mean score = 1.85

The effects were completely reversible after 7 to 14 days.

Additional dermal findings noted during the period included irritation observed in taped area outside the test site and desquamation, which were noted on 6/6 and 5/6 test sites, respectively.

Methyl Ethyl Sulfide is considered to be a slight irritant to the skin of the rabbit.