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Methomyl


Information
Methomyl technical
Methomyl water soluble powders
Methomyl soluble concentrates
Methomyl ultra low volume liquids

S-methyl-1-N-[(methylcarbamoyl)oxy]thioacetimidate

AGP:CP/350

Information

COMMON NAME: methomyl

STRUCTURAL FORMULA

EMPIRICAL FORMULA: C5H10N2O2S

RMM: 162.2

CAS REGISTRY NUMBER: 16752-77-5

CIPAC CODE NUMBER: 264

CHEMICAL NAMES:

S-methyl-1-N-[(methylcarbamoyl)oxy]thioacetimidate (IUPAC)

methyl N-[[(methylamino)carbonyl]oxy]ethanimidothioate (CA)

Methomyl technical

FAO Specification 264/TC/S/P (1997)

1. DESCRIPTION

The material shall consist of methomyl together with related manufacturing impurities and shall be in the form of a powder free from visible extraneous matter and hard lumps.

2. ACTIVE INGREDIENT

2.1 Identity test (Note 1)

An identity test is required if the identity of the active ingredient is in doubt (e.g. I.R. spectrum).

The infrared spectrum of the sample should not differ significantly from that of an authentic sample.

2.2 Methomyl (AOAC-CIPAC method, to be published) (Note 1)

The methomyl content shall be declared (not less than 980 g/kg) and when determined, the content obtained shall not differ from that declared by more than ± 20 g/kg.

3. IMPURITIES

3.1 Water (MT 30, CIPAC F, p. 91)

Maximum: 3 g/kg.

3.2 Insoluble in water (MT 10.2, CIPAC F, p. 27)

Maximum: 2 g/kg.

4. PHYSICAL PROPERTIES

4.1 Melting range (MT 2, CIPAC F, p. 5)

Melting range: 78-79°C.

NOTE 1. Methods available from the Pesticides Information Officer, FAO Plant Production and Protection Division.

Methomyl water soluble powders

FAO Specification 264/SP/S/P (1997)

1. DESCRIPTION

The material shall consist of a homogeneous mixture of technical methomyl, complying with the requirements of FAO specification 264/TC/S/P (1997), together with any necessary formulants. It shall be in the form of a powder free from visible extraneous matter and hard lumps to be applied as a true solution of the active ingredient after dissolution in water but which may contain insoluble inert ingredients.

2. ACTIVE INGREDIENT

2.1 Identity tests (Note 1)

An identity test is required if the identity of the active ingredient is in doubt (e.g. I.R. spectrum).

2.2 Methomyl content (AOAC-CIPAC method, to be published) (Note 1)

The methomyl content shall be declared (g/kg) and when determined, the content obtained shall not differ from the declared by more than the following amounts:

Declared content

Permitted tolerance

above 25 up to 100 g/kg

± 10% of the declared content

above 100 up to 250 g/kg

± 6% of the declared content

above 250 up to 500 g/kg

± 5% of the declared content

above 500 g/kg

± 25 g/kg

3. IMPURITIES

3.1 Water (MT 30, CIPAC F, p. 91)

Maximum: 3 g/kg.

3.2 Material insoluble in water (MT 10.2, CIPAC F, p. 27)

Maximum water insoluble inerts should be declared.

4. PHYSICAL PROPERTIES

4.1 pH range (MT 75.2, CIPAC F, p. 206)

pH range: 3.0 to 8.0.

4.2 Wet sieve test (MT 59.3, CIPAC F, p. 179)

Maximum: 2% retained on a 75 ìm test sieve.

4.3 Rate of dissolution and solution stability (MT 179, CIPAC H, to be published)

After 5 minutes: All the product, other than the insoluble material found under 3.2 shall dissolve in CIPAC Standard Water D at 20 ± 2°C.

After 18 hours: Maximum of 2 g/kg of the product shall be retained on a 75 m m sieve.

4.4 Persistent foam (MT 47.2, CIPAC F, p. 152) (Note 2)

Maximum: 25 ml after 1 minute.

4.5 Wetting of product (MT 53.3.1, CIPAC F, p. 165)

The product shall be completely wetted in 60 seconds without swirling.

5. STORAGE STABILITY

5.1 Stability at 54°C (MT 46.1.1, CIPAC F, p. 149)

After storage at 54 ± 2°C for 14 days (Note 3), the determined average active ingredient content must not be lower than 95% relative to the determined average content found before storage, and the product shall continue to comply with 4.1, 4.2, 4.3 and 4.5.

NOTES

1. Methods available from the Pesticides Information Officer, FAO Plant Production and Protection Division.

2. The mass of the sample to be used in the test should be at the highest rate of use recommended by the supplier.

3. Samples of the product taken before and after storage stability test should be analysed together after the test to reduce the analytical error.

Methomyl soluble concentrates

FAO Specification 264/SL/S/P (1997)

1. DESCRIPTION

The material shall consist of a solution of technical methomyl, complying with the requirements of FAO specification 264/TC/S/P (1997), together with any necessary formulants. It shall be free from visible suspended matter and sediment.

2. ACTIVE INGREDIENT

2.1 Identity tests (Note 1)

An identity test is required if the identity of the active ingredient is in doubt (e.g. I.R. spectrum).

2.2 Methomyl content (AOAC-CIPAC method, to be published) (Note 1)

The methomyl content shall be declared (g/kg) and when determined, the content shall not differ from the declared by more than the following amounts:

Declared content

Permitted tolerance

above 25 up to 100 g/kg

± 10% of the declared content

above 100 up to 250 g/kg

± 6% of the declared content

above 250 up to 500 g/kg

± 5% of the declared content

above 500 g/kg

± 25 g/kg

3. IMPURITIES

3.1 Water (MT 30, CIPAC F, p. 91)

Maximum: 3 g/kg

3.2 Material insoluble in water (MT 10.2, CIPAC F, p. 27)

The maximum water insoluble inerts in water should be declared.

4. PHYSICAL PROPERTIES

4.1 pH range (MT 75.2, CIPAC F, p. 206)

pH range: 3.0 to 8.0

4.2 Flash point (MT 12, CIPAC F, p. 31)

The flash point of the product shall be not lower than 11°C. A closed cup method shall be used and the method stated.

4.3 Dilution stability in water (MT 41, CIPAC F, p. 131)

The product, after the stability test at 54°C (5.2) shall give a clear and homogeneous solution after dilution at 30 ± 2°C with CIPAC Standard Water D.

5. STORAGE STABILITY

5.1 Stability 0°C (MT 39, CIPAC F, p. 129)

After storage at 0 ± 1°C for 7 days, the volume of any solid and/or liquid which separates shall hot be more than 0.3 ml.

5.2 Stability 54°C (MT 46.1.3, CIPAC F, p. 149)

After storage at 54 ± 2°C for 14 days the determined average active ingredient content must not be lower than 95% relative to the determined average content found before storage (Note 2) and the product shall continue to comply with 4.1.

NOTES

1. Methods available from the Pesticides Information Officer, FAO Plant Production and Protection Division.

2. Samples of the product taken before and after storage stability test should be analysed together after the test to reduce the analytical error.

Methomyl ultra low volume liquids

FAO Specification 264/UL/S/P (1997)

1. DESCRIPTION

The material shall consist of a solution of technical methomyl, complying with the requirements of FAO specification 264/TC/S/P (1997), together with any necessary formulants. It shall be free from visible suspended matter and sediment. This formulation may be extended with water.

2. ACTIVE INGREDIENT

2.1 Identity tests (Note 1)

An identity test is required if the identity of the active ingredient is in doubt (e.g. I.R. spectrum).

2.2 Methomyl (AOAC-CIPAC method, to be published) (Note 1)

The methomyl content shall be declared (g/kg) and when determined, the content obtained shall not differ from the declared by more than the following amounts:

Declared content

Permitted tolerance

above 25 up to 100 g/kg

± 10% of the declared content

above 100 up to 250 g/kg

± 6% of the declared content

above 250 up to 500 g/kg

± 5% of the declared content

above 500 g/kg

± 25 g/kg

3. IMPURITIES

3.1 Water (MT 30, CIPAC F, p. 91)

Maximum: 3 g/kg.

3.2 Material insoluble in water (MT 10.2, CIPAC F, p. 27)

The maximum water insoluble inerts should be declared.

4. PHYSICAL PROPERTIES

4.1 pH range (MT 75.2, CIPAC F, p. 206)

pH range: 3.0 to 8.0.

4.2 Flash point (MT 12, CIPAC F, p. 31)

The flash point of the product shall be not lower than 22.8°C. A closed cup method shall be used and the method stated.

4.3 Kinematic viscosity range at 20°C (MT 22, CIPAC F, p. 75)

The kinematic viscosity range of the product shall be declared, and not exceed 50 c.p. when measured with a rotary viscometer.

5. STORAGE STABILITY

5.1 Stability 0°C (MT 39, CIPAC F, p. 128)

After storage at 0 ± 1°C for 7 days, the volume of any solid and/or liquid which separates shall not be more than 0.3 ml.

5.2 Stability 54°C (MT 46.1.3, CIPAC F, p. 150)

After storage at 54 ± 2°C for 14 days (Note 2), the determined average active ingredient content must not be lower than 95% relative to the determined average content found before storage and the product shall continue to comply with 4.1 and 4.3

NOTES

1. Methods available from the Pesticides Information Officer, FAO Plant Production and Protection Division.

2. Samples of the product taken before and after storage stability test should be analysed together after the test to reduce the analytical error.


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