Metam-sodium

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from handbook.

Data source

Reference

Reference 1

Reference Type:

review article or handbook

Title:

Chapter 107 – Metam-Sodium

Author:

Robert Krieger

Year:

2010

Bibliographic source:

Hayes' Handbook of Pesticide Toxicology (Third Edition), 2010, Pages 2293–2306

Reference 2

Reference Type:

review article or handbook

Title:

Acute oral toxicity of Metam-sodium (CAS no: 137-42-8) in rat

Author:

Anna Wypych, George Wypych

Year:

2015

Bibliographic source:

Databook of Biocides, 2015

Reference 3

Reference Type:

review article or handbook

Title:

Acute oral toxicity of Metam-sodium (CAS no: 137-42-8) in rat.

Author:

George Wypych, Anna Wypych

Year:

2015

Bibliographic source:

Databook of Preservatives, 2015.

Reference 4

Reference Type:

secondary source

Title:

Conclusion regarding the peer review of the pesticide risk assessment of the active substance metam.

Author:

European Food Safety Authority (EFSA)

Year:

2008

Bibliographic source:

EFSA Scientific Report (2008) 203, 1-97.

Reference 5

Reference Type:

secondary source

Title:

US EPA-Pesticides; Metam-sodium, US EPA ARCHIVE DOCUMENT

Author:

US EPA

Year:

1994

Bibliographic source:

US EPA-Pesticides; Metam-sodium, US EPA ARCHIVE DOCUMENT, US EPA, 1994

Reference 6

Reference Type:

secondary source

Title:

US EPA-Pesticides; Metam-sodium

Author:

US EPA; Office of Pesticide Programs

Year:

1993

Bibliographic source:

US EPA-Pesticides; Metam-sodium, US EPA; Office of Pesticide Programs, 1993

Reference 7

Reference Type:

secondary source

Title:

Draft Assessment Report (Metam-sodium), ANNEX B.6 Toxicology and metabolism

Author:

European Food Safety Authority (EFSA)

Year:

2007

Bibliographic source:

Draft Assessment Report (Metam-sodium) - Volume 3, Annex B, part 2, B.6, October 2007.

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Acute oral toxicity of Metam-sodium (CAS no: 137-42-8) in rat.

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

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

Details on test material:

- IUPAC Name: Metam-sodium
- InChI: 1S/C2H5NS2.Na/c1-3-2(4)5;/h1H3,(H2,3,4,5);/q;+1/p-1
- Smiles: C(=S)(NC)[S-].[Na+]
- Molecular formula :C2H4NNaS2
- Molecular weight:129.1826 g/mol
- Substance type:Organic

Specific details on test material used for the study:

- IUPAC Name: Metam-sodium
- InChI: 1S/C2H5NS2.Na/c1-3-2(4)5;/h1H3,(H2,3,4,5);/q;+1/p-1
- Smiles: C(=S)(NC)[S-].[Na+]
- Molecular formula :C2H4NNaS2
- Molecular weight:129.1826 g/mol
- Substance type:Organic

Test animals

Species:

rat

Strain:

other: CD rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

not specified

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

not specified

Doses:

640, 800, 1000 or 1600 mg/kg bw

No. of animals per sex per dose:

Total = 40 (Sex/dose)

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were observed for mortality and clinical signs.
- Necropsy of survivors performed: yes

Statistics:

The data obtained did not permit the fitting of a probit line using the standard method. However, it was possible to fit a line if a fixed slope was assumed and a value of 8.333 was used.

Results and discussion

Preliminary study:

A preliminary test was carried out by dosing 2 rats/sex at 1000 mg/kg bw and the acute median lethal dose of metam sodium was in the region of 1000 mg/kg be for males and >1000 mg/kg bw for female rats.

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

896 mg/kg bw

Based on:

test mat.

95% CL:

779 - 1 031

Remarks on result:

other: 50% mortality was observed

Effect levels 2

Sex:

male

Dose descriptor:

LD50

Effect level:

870 mg/kg bw

Based on:

test mat.

95% CL:

715 - 1 059

Remarks on result:

other: 50% mortality was observed

Effect levels 3

Sex:

female

Dose descriptor:

LD50

Effect level:

924 mg/kg bw

Based on:

test mat.

95% CL:

758 - 1 130

Remarks on result:

other: 50% mortality was observed

Mortality:

50% mortality was observed as below –
Male and female rats combined 896 mg/kg bw, with 95% confidence limit of 779-1031 mg/kg bw.
Males only: 870 mg/kg bw, with 95% confidence limit of 715-1059 mg/kg bw.
Females only: 924 mg/kg bw, with 95% confidence limit of 758-1130 mg/kg bw.

Clinical signs:

other: All animals had piloerection, hunched posture, abnormal gait, lethargy, decreased respiratory rate, ptosis, pallor of the extremities, increased salivation. Clonic convulsions and prostration affected animals at 1000 and 1600 mg/kg bw.

Gross pathology:

No macroscopic abnormalities were seen.

Other findings:

not specified

Any other information on results incl. tables

Table - Mortality:

Dose (mg/kg bw)	Death		Day or hours after dosing
	M	F	M	F
640	0	0
800	1	0	Day 2
1000	5	5	4 day 4, 1 after 5 h	4 day 2, 1 after 5 h
1600	5	5	4 after 4 h; 1 after 1 h	3 after 4 h; 2 after 5 h

 

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The acute oral LD50 value was considered as follows –
Male and female rats - 896 mg/kg bw, with 95% confidence limit of 779-1031 mg/kg bw; Male rats - 870 mg/kg bw, with 95% confidence limit of 715-1059 mg/kg bw; and Female rats - 924 mg/kg bw, with 95% confidence limit of 758-1130 mg/kg bw, when male and female CD rats were treated with Metam-sodium (CAS no: 137-42-8) via oral route.

Executive summary:

Acute oral toxicity study of Metam-sodium (CAS no: 137-42-8)was conducted in 40 male and female CD rats at the concentration of 640, 800, 1000 or 1600 mg/kg bw. All animals received metam sodium (510 g/L) via oral gavage route. A preliminary test was carried out by dosing 2 rats/sex at 1000 mg/kg bw and the acute median lethal dose of metam sodium was in the region of 1000 mg/kg be for males and >1000 mg/kg bw for female rats. The data obtained did not permit the fitting of a probit line using the standard method. However, it was possible to fit a line if a fixed slope was assumed and a value of 8.333 was used.The animals were observed for mortality and clinical signs for 14 days. Necropsy was performed. 50% mortality was observed as– Male and female rats combined 896 mg/kg bw; Males only: 870 mg/kg bw; Females only: 924 mg/kg bw. All animals had piloerection, hunched posture, abnormal gait, lethargy, decreased respiratory rate, ptosis, pallor of the extremities, increased salivation. Clonic convulsions and prostration affected animals at 1000 and 1600 mg/kg bw. Body weight was not affected in surviving male animals; surviving females of the group 800 mg/kg bw had decreased body weight. No macroscopic abnormalities were seen. Therefore, LD50 was considered to be 896 mg/kg bw in Male and female rats; 870 mg/kg bw in Male rats and 924 mg/kg bw in Female rats, when male and female CD rats were treated with Metam-sodium (CAS no: 137-42-8) via oral route.