This book reviews the latest developments concerning the analysis, fate, behaviour and toxicity of pyrethroid insecticides. Over the last few decades, pyrethroid insecticides have increasingly replaced organochlorine pesticides due to their relatively lower mammalian toxicity, selective insecticide activity and lower environmental persistence. They represent 25% of global sales of insecticides, and are considered to be “safe� since they are converted to non-toxic metabolites by oxidative metabolism in fish and by hydrolysis in mammals. However, recent studies have demonstrated their environmental ubiquity, their bioaccumulation and their toxicity in various aquatic and terrestrial organisms, and even in humans. Featuring contributions by leading experts, the book discusses the physico-chemical properties and uses of pyrethroid insecticides; the latest chemical analytical methods; their occurrence in the environment, biota and food; and their isomeric and enantiomeric behaviour. It particularly highlights the toxicological effects and human exposure to pyrethroid insecticides, and also offers insights into the effects of the salmon industry on the marine environment with a case study of sea lice treatment using pyrethroids. This comprehensive book is a valuable source of information for environmental scientists, policymakers and producers interested in issues related to pyrethroid insecticides.