Methoxychlor

Methoxychlor is a synthetic organochlorine used as an insecticide. It is applied to protect crops, ornamentals, livestock, and pets against fleas, mosquitoes, cockroaches, and other insects. It has been used to some degree as a replacement for DDT as it is faster metabolized and does not lead to bioaccumulation.

The amount of methoxychlor in the environment is seasonal due to its periodic utilization in farming and foresting. As a powder it is usually mixed with a petroleum-based fluid to be sprayed or used as a dust. It does not dissolve readily in water. Sprayed methoxychlor settles in the ground or may be transported by water, where it can be found in the sediments. Its degradation may take many months. While methoxychlor is ingested and absorbed by living organisms, it is readily released and does not build up in the food chain. It is possible that some metabolites have unwanted side effects.

Human exposure to methoxychlor occurs mostly in people who work with the substance, who are exposed to it during its administration, who consume it with their food, or who live near a toxic waste sites. In high doses the agent can lead to neurotoxicity as observed in animal experiments. In experimental situations toxicity can lead to signs central nervous system depression, diarrhea, and damage to liver, kidney and heart tissue. Methoxychlor can disrupt hormonal functioning by its action as a xenoestrogen. Exposure to children may be higher because they tend to play on the ground, further, their reproductive system may be more sensitive to the effects of methoxychlor as an endocrine disruptor. However, the Environmental Protection Agency (EPA) indicated in 2000, that acute or chronic effects of methoxychlor had not been described in humans. Thus, while the agent has discernible hormonal effects, the significance of such findings for the human condition awaits further elaboration. Methoxychlor is not considered to be carcinogenic or teratogenic.

The EPA has labeled methoxychlor to be in the Toxicity Class IV, and it is available as a General Use Pesticide (GUP). For drinking water, the EPA established 40ppb as the Maximum Contaminant Level (MCL).

Tradenames for methoxychlor include Chemform, Maralate, Methoxo, Methoxcide, Metox, and Moxie.