An important, well-documented characteristic of pyrethrins are that they are photolabile. The molecules easily decompose in the presence of sunlight. The half-life of pyrethrins in the presence of light range from 4 to 8 hours, depending on the position of the radiolabel. The degradation products of pyrethrins are also nonpersistent. Microbial degradation of pyrethrins in aerobic soil have a half life of 10.5 days
In Soil and Water
Pyrethrins are not readily transported from the site of application.Very little movement of pyrethrins and their degradation products from soil into plants or through soil columns
were observed using radiolabeled material. Pyrethrins do not bioaccumulate and are subject to both oxidation and cleavage of their ester linkage in biological systems.
On Nontarget Species
Studies found the oral LD50 of >2000 mg/kg body weight for bobwhite quail and mallard ducks. The LC50 was >5500 ppm of diet for the bobwhite quail and mallard duck. The 96 hour acute flow through LC50 for Bluegills and Rainbow Trout are 10μg and 5.2μg total pyrethrins/