Metam-sodium

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

data from handbook or collection of data

Data source

Reference

Reference 1

Reference Type:

review article or handbook

Title:

Chapter 87 – Metam-Sodium

Author:

Robert Krieger

Year:

2001

Bibliographic source:

Hayes' Handbook of Pesticide Toxicology Volume 2, 2nd ed. 2001

Reference 2

Reference Type:

secondary source

Title:

Metam-sodium - DAR - Vol. 3 - Annex B.6

Author:

European Food Safety Authority (EFSA)

Year:

2007

Bibliographic source:

Metam-sodium - DAR - Vol. 3 - Annex B.6; Volume 3, Annex B, part 2, B.6, October 2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: not fully in agreement with Dir 96/54/EEC Annex IV C or 92/69-84/449 or OECD 406 (1981-92).

Principles of method if other than guideline:

The skin sensitization study was conducted on guinea pigs to determine delayed contact hypersensitivity of test chemical Metam-sodium (CAS no: 137-42-8).

GLP compliance:

not specified

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Metam-sodium

EC Number:

205-293-0

EC Name:

Metam-sodium

Cas Number:

137-42-8

Molecular formula:

C2H5NS2.Na

IUPAC Name:

sodium (methylcarbamothioyl)sulfanide

Test material form:

solid

Specific details on test material used for the study:

- Name of test material : Metam-sodium
- Common name: Sodium methyldithiocarbamate
- Molecular formula : C2H4NNaS2
- Molecular weight : 129.1826 g/mol
- Smiles notation : C(=S)(NC)[S-].[Na+]
- InChl : 1S/C2H5NS2.Na/c1-3-2(4)5;/h1H3,(H2,3,4,5);/q;+1/p-1
- Substance type: Organic
- Physical state: Solid

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

not specified

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

other: distilled water

Concentration / amount:

- Induction phase: metam sodium at 5% in water and metam sodium at 5% in a 50:50 mixture of Freund’s complete adjuvant and
water.
-Topical application of 2.5% v/v in water.

Day(s)/duration:

No data available

Adequacy of induction:

not specified

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: distilled water

Concentration / amount:

1% and 0.5%

Day(s)/duration:

72 hours

Adequacy of challenge:

not specified

No. of animals per dose:

20

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and topical)
- Exposure period: no data
- Test groups: 20
- Control group: no data
- Site: no data
- Frequency of applications: no data
- Duration: no data
- Concentrations: - Induction phase: metam sodium at 5% in water and metam sodium at 5% in a 50:50 mixture of Freund’s complete adjuvant and
water.
-Topical application of 2.5% v/v in water.

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: after 2 weeks
- Exposure period:no data
- Test groups: no data
- Control group: no data
- Site: at two sites of each animal
- Concentrations: 1% or 0.5%
- Evaluation (hr after challenge): 24/48/72 hours

Study design: in vivo (LLNA)

Vehicle:

not specified

Results and discussion

In vivo (non-LLNA)

Results

Reading:

1st reading

Hours after challenge:

72

Group:

test chemical

Dose level:

1% and 0.5%

No. with + reactions:

19

Total no. in group:

20

Clinical observations:

Metam sodium produced evidence of delayed contact hypersensitivity in 19 guinea pigs.

Remarks on result:

positive indication of skin sensitisation

In vivo (LLNA)

Cellular proliferation data / Observations:

Metam sodium produced evidence of delayed contact hypersensitivity in 19 guinea pigs.

Applicant's summary and conclusion

Interpretation of results:

other: Sensitizing

Conclusions:

The test chemical Metam-sodium (CAS no: 137-42-8) was considered to be sensitizing to the skin of guinea pigs.

Executive summary:

The skin sensitization study was conducted on 20 female Dunkin-Hartley guinea pigs to determine delayed contact hypersensitivity of test chemical Metam-sodium (CAS no: 137-42-8).

 

During the induction phase, the Guinea pigs were treated at 5% in water and metam sodium at 5% in a 50:50 mixture of Freund’s complete adjuvant and water intradermally and at 2.5% v/v in water topically.

After a rest period of 2 weeks, the animals were challenged using metam sodium at 1% and 0.5% v/v in water applied at two sites of each animal. The challenge sites were evaluated 24, 48, and 72 h after removal of the patches.

 

Metam sodium produced evidence of delayed contact hypersensitivity in 19 guinea pigs. Therefore, thechemicalMetam-sodium (CAS no: 137-42-8)was considered to be sensitizing to the skin of guinea pigs.