What is Pyrethrin and Pyrethroid Insecticides

Pyrethrin is the oleoresin of the dried chrysanthemum flower. The resin contains several esters with insecticidal acridity, comprising approximately 50% of the ingredients.

These esters are known as pyrethrins. Pyrethrins have been used as insecticides for centuries.

In the United States, reports to poison centers regarding pyrethroid exposure have been quantitatively similar to reports regarding organophosphate insecticide, but with the fewer clinically important poisonings.

During a more recent year of reporting , there were no deaths and most clinical outcomes had either minor or no effects. There were 23 cases of major outcomes for pyrethrins with and without piperonyl.

The word pyrethrin is a general term used for each of the six naturally occurring insecticidal compounds in pyrethrum.

Pyrethrum contains a variable mixture of the six specific pyrethrins:
cinerin I
cinerin II
jasmolin I
jasmolin II
pyrethrin I
pyrethrin II

Pyrethroids are lipophilic and are absorbed, to some degree, via intact skin, lungs or intestinal tract.

Depending on the specific pyrethrin or pyrethroid this absorption may a minor or a major route of absorption.

Skin absorption is slow. Depending on the magnitude of the dose however, the skin is the major pathway of poisoning. When pyrethroids enter the vascular compartment, their half lives range from hours to days.
What is Pyrethrin and Pyrethroid Insecticides