Wettable powder formulations

Wettable powder formulations can be mixed using the procedure described above with the exception that some of the second half of the water should be used to cream the test item into a paste type mixture which can then be poured into the first half of the water. Numerous rinsings will again be required to ensure that the entire test item is removed from its original container and, hence, thoroughly mixed with the second half of the water. 

As the concentration of parathion in the propylene glycol solutions is increased, it follows that the area covered by the solution is decreased. That this is a factor in toxicity is indicated by the greater toxicity of the 10 mg. per ml. solution than the 50 mg. per ml. solution. This relationship appears to be true also of the various dry preparations, in that the 1% powder is somewhat more toxic than the 15%. The addition of water to convert the powder to paste does not appreciably influence the toxicity. In comparable concentrations the wettable powder formulation is less toxic than the propylene glycol solution. 

The use of pure gamma isomer of hexachlorocyclohexane on livestock has also been worked out. It has been found possible to use the wettable powder formulation dispersed in water as a spray on livestock for control of flies, lice, and ticks. Proper dosage and application must be used, of course, but this is again indicative of the safety factor of this insecticide. 

Arthur, F.H. 1994. Residual efficacy of cyfluthrin emulsifiable concentrate and wettable powder formulations applied to sealed and unsealed concrete. J. Stored Prod. Res. 30, 79-86. 

During that same year, various granular formulations (10%, 8%, and 4%) of simazine were approved and introduced in the United States for ornamentals, nursery stock, and com and for total vegetation control in noncropland. Also, a more concentrated (80 W) wettable powder formulation of simazine was approved for the same uses in December 1958. 

On October 21,1959, a more concentrated wettable powder formulation, Atrazine 80 W, was registered and quickly became the leading com herbicide in the United States. Other formulations of atrazine, including various granulars... 

When wettable powder formulation of iprodione was diluted to field strength (0.05% a.i.) and used to contaminate 100% cotton and 65/35 polyester/cotton fabric, it was found that a single warm water wash (50°C) left approximately 1% iprodione residues on the fabric.5... 

Uses Pure azinphos-methyl is a white crystalline solid technical azinphos-methyl is a brown waxy solid. Based on toxicity, the USEPA has grouped it under RUP. Azinphos-methyl is a highly persistent, broad-spectrum insecticide. It is used for the control of mites and ticks, and it is poisonous to snails and slugs. It also is used in the control of many insect pests on a wide variety of fruit, vegetable, nut, and held crops, as well as on ornamentals, tobacco, and forest and shade trees. Outside the United States, azinphos-methyl is used in lowland rice production. Azinphos-methyl is available in emulsihable liquid, liquid flowable, ultra-low volume (ULV) liquid, and wettable powder formulations.28,29... 

Uses Technical ethion is an odorless amber liquid. Ethion is used to kill aphids, mites, scales, thrips, leafhoppers, maggots, and foliar feeding larvae. It may be used on a wide variety of foods, fibers, and ornamental crops, including greenhouse crops, lawns, and turf. Ethion often is used on citrus and apples. It is mixed with oil and sprayed on dormant trees to kill eggs and scales. Ethion also may be used on cattle. It is available in dust, emulsifiable concentrate, emulsifiable solution, granular, and wettable powder formulations.28... 

Uses The formulations of fenitrothion include dusts, emulsifiable concentrate, flowable, fogging concentrate, granules, ultra-low volume, oil-based liquid spray, and wettable powder formulations (Novathion 500-E, EC as a 95% concentrate,... 

Uses Bromacil is a colorless crystalline solid. It is used for the control of annual and perennial grasses, broadleaf weeds, and woody plants.1213 Bromacil is a herbicide used for bush weed control on non-cropland areas. It is especially useful against perennial grasses. It is also used for selective weed control in pineapple and citrus crops. It interferes with photosynthesis of plants. It is available in granular, liquid, water-soluble liquid, and wettable powder formulations. 

The stability of toxicant-carrier combinations used in pesticide wettable powder formulations cannot be easily predicted by evaluating various properties of the carrier. Several types of synthetic calcium silicates and their modifications were evaluated for malathion stability and other properties. The carriers were evaluated for pH (slurry), pK (surface acidity), moisture content, absorptive capacity, and/or ion exchange capacity. These properties were correlated with actual malathion stabilities as measured at 40° C. storage for 1, 2, 3, and 7 months. The carrier properties evaluated did not offer a simple means of predicting compatibility in the variety of carriers tested. 

In two experiments 2,6-dichlorobenzonitrile was added to aquatic systems, and the residue levels were followed for about 6 months. A granular formulation applied to a farm pond at 0.6 p.p.m. produced highest residues in water and fish about 2 weeks following treatment whereas vegetation and soil samples had the highest levels within 1 or 2 days. Residues were still measurable after 188 days. In ponds treated with a wettable powder formulation at 10, 20, and 40 p.p.m., residues in water and fish were highest within 3 days after treatment. The concentration in water 11 days after treatment was about 2% of the three-day level. Fish whole-body residues dropped nearly as fast but were still measurable at 112 days. 

Eight 0.1-acre experimental ponds at Tishomingo were stocked with bluegills and were treated June 5, 1964. A wettable powder formulation was used which was calculated to yield dichlobenil concentrations of 0, 10, 20, and 40 p.p.m. Fish and water were sampled beginning 3 days following treatment. The final water sample was taken 85 days, and the final fish sample 112 days after treatment. Bottom soil samples beginning 1 month after treatment were supplemented by samples taken after the ponds were drained. 

The phytotoxicity and acarlcldal activity of this new formulation is shown in Table V. A commercial wettable powder formulation of propargite, Omlte 30W, was used for conparison purposes. 

A wettable powder formulation of a biological insecticide requires a surface active agent (surfactant). This allows... 

Cell suspension tests can Indicate tdilch type of surfactant could be potentially incompatible after long periods of storage. Three basic types of surfactants exist anionic, cationic, and non-ionic. Parr (27) surmised that anionic surfactants are the least phytotoxic, but the results of Ernst (28) do not confirm that all anionic surfactants are harmless. Surfactants with short, aliphatic, carbon chains may also be more toxic than those with larger molecular groups (29). The surfactant s influence iii vitro may exaggerate the effect in dry, wettable powder formulations, and thus provide an accelerated test of compatablllty. 

Wettable powder formulations of pyrethrins synergized with PRO were found to be longer-lasting for surface sprays against Indian meal moth, Plodia stuer-puncteila (Hubner), than water-diluted emulsions (Kanlack and Laudani, 1957. This is because of absorption of the active material into surface substrates when emulsion concentrates are used, whereas wettable powders leave a residual surface deposit, even if the water penetrates the surface,... 

Table XI. Amount of Carbaryl Active Ingredient Adhering to Individual Pads or Hands as a Function of Body Location and of Plant Height. Wettable Powder Formulation (12 Replications)...

Once contaminated usual textile items in pesticide applicators wardrobes are difficult to decontaminate through laundering procedures currently in use. The laundering procedures reduced residues to less than one percent to as much as 20 percent of the original contamination, depending upon MeP formulation. Residues were lower after laundering when the contamination had been from encapsulated and wettable powder formulation and were greater for the emulslflable concentrate formulation. The nature of the soil, its particulate make up, or its oil-based emulsion are felt to contribute to limited... 

Pesticide formulation and volatility of the chemical greatly affects the ratio of airborne to surface residues. Wettable powder formulation of permethrin resulted In an airborne concentration of 0.39 ug/1 during the first 2 hours after application, whereas the emulslflable concentrate of the same pesticide resulted In a concentration of 2.82 ug/1. The surface deposition of benomyl averaged approximately 750 ng/cm from a HV application and 632 from an LV application (Figure 2) and airborne residues were not measurable 1 hour after application. Approximately 33 percent of the benomyl deposition from the HV application was on the under surface of the glass plate, whereas only 1 percent from the LV application was so deposited. 

The diet assay involves the uniform incorporation of a 5% wettable powder formulation of the compound into an artifical casein diet. Southern armvworms(Soodoptera literalis are allowed to feed on this diet for 4-days, after which time the the number of dead and living insects are counted. 

Wettable powder formulations can utilize a variety of mineral carriers and solid diluents, either singly or in combination. When the active ingredient is a liquid the formulator will want a highly sorptive carrier. Attapulgite is the primaiy choice when the highest possible concentration is to be attained, with montmorillonite sometimes receiving consideration. 

Impregnation for dust, water dispersible granule, and wettable powder formulations is accomplished using the same ribbon blender as for mixing, with the addition of a spray bar to the blender. 

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