Specific phosphate esters constitute amajor category of organic insecticides, known as organophosphates (Costa, 2013).
These phosphate and phosphite esters, lacking significant insecticidal properties, are widely used as plasticizers and gasoline additives to control preignition. Included in this group are TOCP, triphenyl phosphate, butylated triphenyl phosphate, tri-2-ethylhexyl phosphate, and 2-ethylhexyl diphenyl phosphate. As plasticizers, these compounds offer an additional flame retardant property and are widely used in vinyl and cellulose formulations. Nonparalytic isomers have been used as plasticizers in the manufacture of vinyl plastics, as solvents in cellulosic molding compositions, as additives to extreme pressure lubricants, as inflammable fluids in hydraulic systems, and also as a lead scavenger in gasoline (Budavari, 1996).
The majority of reported cases of phosphate ester poisonings have been associated with ingestion of esters in contaminated food or drink, not occupational exposures. The most frequent occupational exposures to phosphate esters occur during manufacture, packaging, shipping, and storage, not at the point of product use. Increased absorption of phosphate esters has been noted with increased workplace temperatures. Phosphate esters tend to accumulate in fatty tissues, and hence have a long biological half-life (LeBel and Williams, 1986). Bisesi (1994) provides a more thorough discussion of the phosphate esters and their hazards.
