|FAO specifications for plant protection products. Fungicides: Flusilazole (tentative). Herbicides: Chloridazon, Chlorsulfuron (tentative), Diflufenican, Metsulfuron Methyl. Insecticides: Methomyl, Thiodicarb. Plant growth regulators: Ethephon. (1998)|
FAO Specification 543/WG/S/F (1997)
The material shall consist of a homogeneous mixture of technical thiodicarb, complying with the requirements of FAO Specification 543/TC/S/F (1997), together with filler(s) and any other necessary formulants in the form of granules to be applied after desintegration and dispersion in water. The product shall be dry, free-flowing and free from visible extraneous matter and hard lumps.
2. ACTIVE INGREDIENT
2.1 Identity tests (543/WG/M/2, CIPAC H, to be published) (Note 1)
An identity test is required if the identity of the active ingredient is in doubt (e.g. chromatographic retention time under conditions of the method of analysis or IR spectrum).
2.2 Thiodicarb (543/WG/M/3, CIPAC H, to be published) (Note 1)
The thiodicarb content shall be declared (g/kg) and, when determined, the content obtained shall not differ from that declared by more than the following amounts:
up to 500 g/kg
± 5% of the declared content
above 500 g/kg
± 25 g/kg
3.1 Manufacturing impurities (Note 1)
Methomyl: Maximum 0.5% of the thiodicarb content found under 2.2.
3.2 Water (MT 30, CIPAC F, p. 91)
Maximum: 15 g/kg.
4. PHYSICAL PROPERTIES
4.1 pH range (MT 75.2, CIPAC F, p. 205)
pH range: 4.0 to 7.0.
4.2 Wetting of the product without swirling (MT 53.3.1, CIPAC F, p. 165)
It shall be completely wetted in 2 minutes without swirling.
4.3 Wet sieve test (MT 167, CIPAC F, p. 416)
Maximum: 1 % retained on a 75 mm test sieve.
4.4 Suspensibility (MT 168, CIPAC F, p. 417) (Notes 2 and 3)
A minimum of 70 % of the thiodicarb content found 2.2 shall be in suspension after 30 minutes in CIPAC Standard Water D at 30°C ± 2°C.
Alternatively, if the buyer requires other CIPAC Standard Waters or temperatures to be used, then this shall be specified.
4.5 Degree of dispersion (MT 174, CIPAC F, p. 435)
4.6 Persistent foam (MT 47.1, CIPAC F, p. 152)
Maximum: 15 ml after 1 minute (10 g/l dilution).
4.7 Dustiness (MT 171.1, CIPAC F, p. 425) (Note 4)
Maximum: 12 mg collected dust.
4.8 Flowability (MT 172, CIPAC F, p. 149)
100% of the product shall pass through a 5 mm test sieve after 20 drops of the sieve.
5. STORAGE STABILITY
5.1 Stability at 54°C (MT 46.1.1, CIPAC F, p. 149)
After storage at 54°C ± 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, and the product shall continue to comply with: 3.1, 4.1, 4.3, 4.4 and 4.5 (Note 5)
1 Methods available from the Pesticides Information Officer, FAO Plant Production and Protection Division.
2. Chemical assay is the only fully reliable method of measuring the mass of active ingredient still in suspension. However, simple methods such as gravimetric and solvent extraction determination may be used on a routine basis provided that these methods have been shown to give equal results to those of the chemical assay method. In case of dispute the chemical method shall be the Referee method.
3. The product should be tested at the highest and lowest rates of use recommended by the supplier, provided this is consistent with the conditions given in method, MT 168 CIPAC F, p. 417.
4. The optical method (MT 171.2) usually shows good correlation to the gravimetric method (MT 171.1) and can therefore be used as an alternative,. where the equipment is available. Where the correlation is in doubt, it must be checked with the product to be tested.
5. Analysis of the product before and after storage should be carried out at the same ime (i.e. after storage) to reduce the analytical error.