TABLE 1.

Major Pesticide Classes and Selected Examples

Pesticide Class	Examples	Toxicity	Comment, Uses
Organochlorines	DDT, endrin, aldrin, chlordane, lindane	High toxicity	Many organochlorines now banned in the United States Lindane has been banned in California, elsewhere used for control of lice and scabies DDT and other organochlorines have long metabolic disposition and are stored in fatty tissues and can persist in the environment
Organophosphates	Parathion, chlorpyrifos, dichlorvos, acephate, methyl-parathion, malathion, phorate	Most OPs are highly toxic Malathion is considered relatively less toxic than other OPs	Parathion is banned for use in the United States Chlorpyrifos is no longer approved for residential use Most others are used for insect control in both agricultural and home settings Malathion is an approved treatment of head lice
N-Methyl carbamates	Aldicarb, carbaryl, carbofuran, pirimicarb, propoxur	Aldicarb and carbaryl are both highly toxic Other carbamates have a relatively moderate toxicity	Insect control in agricultural and home settings
Pyrethrins and pyrethroids	Permethrin, cyano-pyrethroids: deltamethrin, cypermethrin, fenvalerate	Permethrin has relatively low toxicity Other pyrethroids have moderate toxicity	Permethrin is a common pediculicide Most other pyrethroids are commonly used to control insects, often used in home and garden
Neonicotinoids	Imidacloprid	Relatively newer class of insecticides Have relatively lower toxicity than OPs and carbamates	Selective affinity toward insect nicotinic acetylcholine receptors compared with mammalian nicotinic acetylcholine receptors Often used as spot-on flea control for domestic animals
N-Phenylpyrazole insecticides	Fipronil	Relatively newer class of insecticides	Often used as spot-on flea control for domestic animals Yard treatments for insect control
Phosphonate herbicides	Glyphosate	Because of primary mechanism of action, has relatively low toxicity from active ingredient. Toxicity often due to the accompanying organic solvent	Acts on plant cell wall Commercially available in many products
Chlorophenoxy herbicides	2,4-D, 2,4,5-T	Moderate toxicity	Weed control
Dipyridyl herbicides	Paraquat, diquat	Highly toxic	Infrequently used Paraquat toxicity often requires lung transplant
Long-acting anticoagulants	Brodifacoum (superwarfarins)		Rodenticides Longer-acting than warfarin Recently eliminated packaging as loose pellets

2,4,5-T, 2,4,5-trichlorophenoxy acetic acid.