A pyrethroid is a synthetic chemical used as a pesticide. The pyrethroids are the synthesized version of pyrethrins, naturally occurring pesticides found in some members of the chrysanthemum family. These plants are in fact sometimes recommended for companion planting to keep bugs out of the garden, and they can also be processed to extract useful pyrethrins which can be used for insect control. Using synthetics tends to be cheaper, making pyrethroids more appealing to pesticide manufacturers.
The earliest pyrethroids were developed in the 1960s, and the chemicals have gone through several incarnations since this period. When insects are exposed to a pyrethroid, the pesticide acts as a paralytic agent, and it may be combined with a chemical which blocks enzymes in the body of the insect to ensure that the paralysis is lethal. Since the use of organophosphate pesticides has declined, pyrethroids have become a very popular pesticide product.
These chemicals can be found in insect repellent, household insect spray, and industrial sprays for insects which infest crops. They are also used in medications which are designed for the treatment of conditions caused by insects, such as scabies, and they are used for flea control in some animals. However, pyrethroids can be very dangerous for some animals, such as cats, and they need to handled with special care.
When released into the environment, pyrethroids generally break down quickly in air and water. However, they can accumulate in sediments. This is an issue, because aquatic organisms are sensitive to pyrethroids and these pesticides can impact populations in lakes, rivers, and streams. Care should be taken when using pyrethroids outdoors to avoid dispersing them into waterways for this reason.
Studies on pyrethroid toxicity have shown that these compounds can also sometimes cause skin irritation and other reactions in sensitive people. It can be difficult to predict when someone will be sensitive to pyrethroids, making it a good idea to wear appropriate protections when working with these pesticides. People should also follow the recommendations on pesticide containers closely to reduce the risk to themselves and the natural environment.
Pyrethroid insecticide sprays can be found at many hardware and gardening stores, along with accessory equipment such as sprayers and face protection. If people are not sure about which pesticide would be appropriate for a particular application, staff members can provide recommendations and advice. Any spray which contains a pyrethroid should be kept out of reach of children and pets.