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Propoxur volatilizes in the air and can be absorbed into the blood weeks after application. It is also thought to be a cardiovascular or blood toxicant, a possible human carcinogen, a  reproductive toxicant, and  a neurotoxicant, due to its cholinesterase inhibiting properties, but it is not thought to be bioaccumulative.<ref>http://toxipedia.org/display/toxipedia/Propoxur</ref>     

Propoxur volatilizes in the air and can be absorbed into the blood weeks after application. It is also thought to be a cardiovascular or blood toxicant, a possible human carcinogen, a  reproductive toxicant, and  a neurotoxicant, due to its cholinesterase inhibiting properties, but it is not thought to be bioaccumulative.<ref>http://toxipedia.org/display/toxipedia/Propoxur</ref>     

Normally, it takes about ten years testing on rats and dogs for mutagenic effects and costs about $200 million for such a chemical to be approved by the EPA.

Normally, it takes about ten years testing on rats and dogs for mutagenic effects and costs about $200 million for such a chemical to be approved by the EPA. <ref>Linda Moulton Howe, Invasion of “Super Bed Bugs” in America'', Earthfiles.com</ref> /

===Natural  insecticides===

===Natural  insecticides===