Pesticides: Emulsifiable Concentrates (E or EC)
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.
An emulsion is a special kind of suspension: a mixture made by suspending droplets of one liquid in another. Each ingredient retains its unique properties and identity. To make an emulsion, an active ingredient is dissolved in an oil-based solvent and then further diluted with water. Some agitation may be necessary to keep an emulsion from separating. However, most emulsion pesticide product formulations have additives (emulsifiers or emulsifying agents) that prevent the product from settling. As a rule, emulsions have a “milky” appearance. An emulsifiable concentrate (E or EC) is an emulsion. Homogenized milk is an example of an emulsion.
Some pesticide products are sold in concentrate form and must be mixed or diluted before use. Concentrates come in both liquid and solid form. An emulsifiable concentrate is an example of a liquid concentrate (LC).
Emulsifiable Concentrates (E or EC)
An emulsifiable concentrate formulation usually contains an oil-soluble liquid active ingredient, one or more petroleum-based solvents, and a mixing agent. The mixing agent allows the formulation to be mixed with water to form an emulsion. Most ECs contain between 2 and 6 pounds of active ingredient per gallon. ECs are among the most versatile formulations. They are used against pests in agricultural, ornamental and turf, forestry, structural, food processing, livestock, and public health settings. ECs are adaptable to many types of application equipment, from small, portable sprayers to hydraulic sprayers, low-volume ground sprayers, mist blowers, and low-volume aircraft sprayers.
- Relatively easy to handle, transport, and store.
- Easy to pour and measure.
- Little agitation required; will not settle out or separate when equipment is running.
- Not abrasive; does not cause excessive equipment wear.
- Will not usually plug screens or nozzles.
- Leave little visible residue on treated surfaces.
- High concentration of active ingredient(s) makes it easy to overdose or underdose through mixing or calibration errors.
- May damage treated plants or surfaces (petroleum-based solvents or overdosing may cause phytotoxicity).
- Easily absorbed through skin of humans or animals.
- Splashes and spills are relatively difficult to clean up and/or decontaminate.
- Many have a strong odor.
- Solvents may cause equipment “wear and tear.” For example, rubber or plastic hoses, gaskets, pump parts, and other exposed surfaces may deteriorate.
- May cause pitting or discoloration of painted finishes or other treated surfaces.
- Flammable; should be used and stored away from heat or open flame.
- May be corrosive.