Pyrethroids are organic compounds, which are synthesised through modification and insertion of various functional groups, based on the structure of pyrethrum, a natural insecticide. Depending on their properties (persistency, stability, volatility, etc.) a distinction is made between short-term and long-term pyrethroids. Especially compounds with high persistence in an indoor environment result in longer persistent contamination (e.g., air, dust, surfaces), in some cases up to several years. Pyrethroids are often used indoors to control pests and weeds. They are used by both professional pest controllers and residents in the form of insecticide-containing household products (insect sprays, gels, strips, dusting preparations, electric evaporators). Pyrethroids are also used in the household as veterinary medicine and for human therapy. In addition, pyrethroids find application as moth and beetle proofing agents for the treatment of domestic textiles. This standard describes a method for the analysis of pyrethroids in indoor air. It also describes the determination of piperonyl butoxide (PBO).