A registered product name, Decathlon is a man-made insecticide used for the control of a vast array of insect species in greenhouse or outdoor ornamental plant areas. Decathlon is often used on apple trees, peach trees or vegetables to eradicate insect pests. According to the Extension Toxicology Network, ingredients in Decathlon did not test as carcinogenic (cancer-causing) in rats and mice.
Decathlon is a synthetic pyrethroid. It is a man-made chemical that mimics the naturally-occurring pyrethrum compounds traditionally harvested from members of chrysanthemum group of plants. Within the large group of insecticides known as sythetic pyrethroids, Decathlon's primary active ingredient is cyfluthrin.
While mimicking the insect-killing properties of natural pyrethrin derived from plants, the synthetic compounds in Decathlon have been engineered to perform better. For example, pyrethrin quickly breaks down in sunlight according to the Extension Toxicology Network, but Decathlon's active ingredient cyfluthrin is structured to be effective for a longer period in sunlight although it eventually does break down. Decathlon acts on insects by being physically absorbed into their bodies.
Overall, cyfluthrin is available as both a restricted-use or general-use insecticide. Decathlon is a restricted-use insecticide, meaning it is appropriate for use by trained professionals in certain designated horticultural areas. In the United States, Decathlon is rated for commercial use only and purchased as a wettable powder (WP) concentrate that is mixed with water and sprayed directly on plants and insect pests.
Cyfluthrin in Decathlon is highly toxic to fish and other vertebrate and invertebrate aquatic animal life according to the Decathlon 20 WP product label as well as the Extension Toxicology Network. Freshwater must be covered to avoid even spray-drift from reaching the water's surface, animal skin, or shoreline habitat. Moreover, Decathlon is highly toxic to honeybees and many other beneficial insects in the garden such as praying mantids, ladybugs or mealybug destroyers.
People applying Decathlon are required by U.S. law to following directions and guidelines on the product label, including wearing appropriate personal protection equipment of waterproof gloves, long pants and socks and shoes. While not toxic to humans, avoid getting the powder or spray solution in eyes or bare skin. The Extension Toxicology Network mentions cyfluthrin is absorbed through the skin, especially in open wounds like scratches, scrapes or cuts. The non-profit agency Beyond Pesticides notes that inhalation of minute spray particles may result in a pollen allergen-like respond with sneezing, redness and modified breathing, especially in children. This chemical is quickly cleansed from the body via urine or feces within 24 hours according to the Extension Toxicology Network.