Methomyl

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Ministry of Agriculture, Forestry and Fisheries of Japan 12-Nouan-8147

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Methomyl

EC Number:

240-815-0

EC Name:

Methomyl

Cas Number:

16752-77-5

Molecular formula:

C5H10N2O2S

IUPAC Name:

(E)-[1-(methylsulfanyl)ethylidene]amino N-methylcarbamate

Test material form:

solid: crystalline

Specific details on test material used for the study:

- Substance name: Methomyl Technical
- Substance ID: DPX-X1179
- Lot#: X1179-599
- Purity: 99.6%

Test animals

Species:

rabbit

Strain:

other: New Zealand albino

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Robinson Services, Inc. Clemmons, North Carolina
- Age at study initiation: Young adult
- Weight at study initiation: 2449-2596 g
- Housing: One animal per cage
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 6 or 13 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18-21°C
- Humidity: 35-63%
- Photoperiod: 12 hour light/dark cycle

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

other: distilled water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

0.71 g

Duration of treatment / exposure:

4 hours

Observation period:

Immediately following patch removal, at approximately 30-60 minutes, 24, 48, and 72 hours after patch removal

Number of animals:

1 male and 2 female animals

Details on study design:

TEST SITE
- Area of exposure: Dorsal area and the trunk
- Coverage: 6-cm²
- Type of wrap if used: Semi-occlusive 3-inch Micropore tape

REMOVAL OF TEST SUBSTANCE
- Washing: Test sites were gently cleansed
- Time after start of exposure: 4 hours

OBSERVATION TIME POINTS
Immediately following patch removal and at approximately 30-60 minutes after each patch removal, and 24, 48, and 72 hours after patch removal.

SCORING SYSTEM:
- Method of calculation: Draize scoring system (1944)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

There was no edema observed at any treated dose site during the study. Very slight erythema (score of 1) was noted for all three treated dose sites. All animals were free from dermal irritation by 48 hours.

Other effects:

All animals appeared active and healthy and gained body weight during the study. Apart from the very slight erythema, there were no other signs of gross toxicity, adverse clinical signs, or abnormal behavior.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Not irritating in rabbits

Executive summary:

A primary skin irritation test was conducted with rabbits to determine the potential for the test substance to produce irritation after a single topical application. The study was conducted according to OECD guideline 404 and OPPTS 870.2500.

The study was conducted in a stepwise manner using a single patch applied initially to one rabbit for 4 hours. Five-tenths of a gram of the test substance was moistened with distilled water and then applied to the skin of one healthy rabbit for 4 hours. The dose site was evaluated for dermal irritation by Draize method. immediately following patch removal, and at 30-60 minutes and at 24, 48, and 72 hours after patch removal. Since only minimal dermal irritation was observed in this animal, the test was completed on two additional animals, as described above.

There was no edema observed at any treated dose site during the study. Very slight erythema (score of 1) was noted for all three treated dose sites. All animals were free from dermal irritation by 48 hours.

All animals appeared active and healthy and gained body weight during the study. Apart from the very slight erythema, there were no other signs of gross toxicity, adverse clinical signs, or abnormal behavior.