Pesticides formulations: Flowables (F or AF)
A pesticide formulation is a combination of active and inert ingredients that forms an end-use pesticide product. Pesticides are formulated to make them safer or easier to use. This is because many pesticide active ingredients, in “pure” (technical grade) form, are not suitable for application. In their concentrated form, some are extremely toxic, many do not mix well with water, some are unstable, and some are difficult (or unsafe) to handle, transport, or store. To address these problems, manufacturers add inert ingredients to end-use pesticide products. Inert ingredients have no pesticidal activity, and some simply serve as diluents or carriers.
Flowables (F or AF)
Some active ingredients are insoluble solids: substances that will not dissolve in either water or oil. These may be formulated as flowables. (Most manufacturers use the letter “F” by the trade name to designate that the formulation is a flowable. However, some use the letter “L,” meaning that an insoluble material is presented in “liquid” form.) Most flowables are prepared by first impregnating them onto a dry carrier, such as clay. Then, the active ingredient plus carrier (or the active ingredient alone) are ground into a fine powder. Next, the fine powder is suspended in a very small amount of liquid (and perhaps other inert ingredients). The resulting product is a thick liquid suspension.
Flowables combine many of the characteristics of liquid emulsifiable concentrates and dry wettable powders. Flowables are often used for the same types of pest control operations as Emulsifiable concentrate (ECs).
- Easy to handle and apply; low exposure risk.
- Generally not phytotoxic.
- Seldom clog nozzles.
- Splashes are less likely than with other liquid formulations.
- May settle; need shaking before measuring and mixing.
- Difficult to remove all of product from the container. Containers may be difficult to rinse.
- Require moderate agitation.
- May be abrasive; contribute to “wear and tear” of spray application equipment.
- Spills may be harder to clean up.
- May leave a visible residue on treated surfaces.