At a glance
| Chemical family | Synthetic pyrethroid — Type I (no alpha-cyano group; causes tremor (T-syndrome) in insects) |
| CAS number | 82657-04-3 |
| Classification | IARC Group 3 (not classifiable as to carcinogenicity). EPA Group C (possible human carcinogen — bladder tumours in mice). WHO Class II (moderately hazardous). One of the most frequently detected pyrethroids in house dust |
| Where you encounter it | Professional pest control (termite barriers, ant control, bed bug treatment); agricultural insecticide; applied around foundations, baseboards, and bed frames; house dust (one of the most abundant pyrethroids detected) |
| Sleep micro-environment relevance | One of the most frequently detected pyrethroids in house dust. Applied near sleep environments during pest treatment. Persists on indoor surfaces for months |
Regulatory & certification status
| European Union | Not approved as a plant protection product (approval expired, not renewed). Not authorised under the Biocidal Products Regulation for indoor use. Regulatory |
| United States | EPA-registered for residential and agricultural use. Group C (possible human carcinogen). Conditional registration for some uses. Commonly used by pest control operators. Regulatory |
| Canada | PMRA-registered for residential and agricultural pest control. Regulatory |
| International | IARC Group 3 (as part of pyrethroid group evaluation). EPA Group C. WHO Class II (moderately hazardous). Widely used globally for pest management. Regulatory |
What it is
Bifenthrin is a Type I synthetic pyrethroid — it lacks the alpha-cyano group present in Type II pyrethroids (cypermethrin, deltamethrin). It is one of the most widely used residential and agricultural pyrethroids globally. IARC has not individually classified bifenthrin but evaluated pyrethroids as a group under Group 3. The US EPA classified bifenthrin as Group C (possible human carcinogen) based on urinary bladder tumours in mice at high doses — the relevance of this finding to human cancer risk at residential exposure levels is debated. Bifenthrin has very low water solubility and binds strongly to soil and dust particles, which contributes to its persistence in indoor environments. It is effective against a wide range of insects including termites, ants, bed bugs, and mosquitoes.
Where it shows up in bedding
Bifenthrin enters the bedroom through professional pest control applications. It is commonly applied around bed frames, baseboards, and along the perimeter of rooms during termite and ant treatments. For bed bug control, bifenthrin may be applied to bed frame joints and crevices. After application, bifenthrin binds to dust particles and remains on treated surfaces for months. House dust surveys consistently rank bifenthrin among the most frequently detected and most abundant pyrethroids in US homes. During sleep, exposure occurs through inhalation of resuspended particles, dermal contact with contaminated surfaces, and dust ingestion. Children are more exposed due to hand-to-mouth behaviour and more time near floor level.
Citations
- Trunnelle, K.J. et al. (2014). Concentrations of the urinary pyrethroid metabolite 3-phenoxybenzoic acid in farm worker families in the CHAMACOS cohort. Environmental Research, 131: 153-159. Source Peer-reviewed
- EPA. Bifenthrin — Summary Document for Registration Review. Source Regulatory
- ATSDR (2003). Toxicological Profile for Pyrethrins and Pyrethroids. Source Regulatory
Frequently asked questions
Is bifenthrin in house dust harmful?
At typical residential dust concentrations, bifenthrin is not expected to cause acute health effects. Its EPA Group C classification (possible human carcinogen) is based on high-dose animal studies and the relevance to human cancer risk at residential exposure levels is uncertain. However, bifenthrin is one of the most persistent pyrethroids in indoor environments and children's exposure may be higher due to more dust contact. Reducing dust through regular cleaning lowers exposure.
How long does bifenthrin persist indoors?
Bifenthrin is one of the most persistent pyrethroids in indoor environments. It binds strongly to dust particles and is resistant to degradation in the absence of UV light and microbial activity. Indoor residues can persist for 3-12 months after application, depending on surface type and cleaning frequency. This persistence is intentional for pest control efficacy but means extended exposure for occupants.
Related compounds
Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress.
Last reviewed 2026-07-08. If you find a factual error, contact us.