Product Profile: Bug Repellent

DEET – N,N-diethyl-meta-toluamide, otherwise known as DEET, is a popular active ingredient used in insect repellents. It was first developed by the U.S. Army in 1946 and was later made available to the general public in 1957. In their latest safety review in 2014, the U.S. Environmental Protection Agency (EPA) reaffirmed its assessment that DEET does not present a health concern ^[1]. However, DEET exposure has been associated with eye and skin irritation, nausea, among other similar effects ^[2]. Though rare, it is worth noting that adverse neurological effects such as seizures have been observed in some cases following DEET exposure via ingestion ^[3]. DEET does not dissolve well in water and is regularly detected in water systems and in aquatic environments ^[4]. It has also been found to be harmful to aquatic life including fish, birds, aquatic invertebrates, and plant life ^[5][6][7].

Picaridin – Picaridin, also known as icaridin, is a synthetic compound belonging to the piperidine (a compound originally isolated from pepper) family that has been recognized as a repellent by the U.S. Centers for Disease Control (CDC) since 2005 (though it has been sold in Europe since 1998) ^[8]. Current research suggests that it does not pose severe concerns for humans, although it has been classified by the EPA as slightly toxic (Toxicity Category III) in cases of eye irritation and acute dermal and oral exposures ^[9]. The main concern with picaridin is environmental, as it is moderately toxic to fish ^[10].

Pyrethroids – Pyrethroids are a popular choice among active ingredients in household insecticides, lice treatments, mosquito repellent clothing treatments, pet sprays, and more. Pyrethroids are synthetic derivatives of natural pyrethrins, which are extracted from chrysanthemum flowers. Unlike DEET and picaridin which simply repel insects, pyrethroids are insecticides and function by attacking the insect’s nervous system via the sodium channels, eventually leading to the death of the insect.

Permethrin, a Type II pyrethroid, has a wide variety of applications including use on food/feed crops, livestock, outdoor clothing and gear, pet products, public spaces as part of Public Health mosquito abatement programs, and as a treatment for head lice and scabies. One major concern is that it is highly toxic to aquatic life as well as to honeybees and other beneficial insects ^[11]. For human consideration, the EPA has classified permethrin as “Likely to be Carcinogenic to Humans” by the oral route ^[12] and a 2014 case study found acute permethrin exposure to be associated with nausea, vomiting, and neurotoxicity ^[13]. One animal study found that rats subjected to chronic low-dose exposure of permethrin suffered damage to both the liver and kidneys ^[14]. In humans, exposure to permethrin through contact or inhalation has also been linked to skin and eye irritation, sore throat, abdominal pain, nausea, headaches, difficulty breathing, and more ^[15].

Cyfluthrin, a Type I pyrethroid, can often be found in agricultural applications, residential and yard pesticide treatments, and as a wood protectant. Cyfluthrin can cause eye, skin, and respiratory irritation, as well as headaches, nausea, and vomiting. It is considered toxic if ingested or inhaled, in both cases leading to fatalities ^[16]. Lastly, cyfluthrin is very toxic to aquatic life with long lasting effects ^[17] and highly toxic to bees ^[18].