At a glance
| Chemical family | Neonicotinoid — nicotinic acetylcholine receptor agonist (chloronicotinyl insecticide) |
| CAS number | 138261-41-3 |
| Classification | Not classified by IARC. EPA not classified as a human carcinogen (Group E for some data). WHO Class II (moderately hazardous). EU banned for outdoor agricultural use (2018, pollinator protection). Selective for insect over mammalian nicotinic receptors |
| Where you encounter it | Pet flea treatments (Advantage); termite control (Premise); agricultural pest control; turf and ornamental pest control; transfers to house dust from pet contact and building treatment |
| Sleep micro-environment relevance | Transfers to bedding from pets treated with imidacloprid-based flea products. Also present in house dust in termite-treated structures. Two pathways into the sleep environment |
Regulatory & certification status
| European Union | Banned for outdoor agricultural use since 2018 (Commission Implementing Regulation 2018/783) due to bee toxicity. Authorised for some indoor biocidal uses and veterinary products (pet flea treatments). EFSA pollinator risk assessment drove the ban. Regulatory |
| United States | EPA-registered for residential, agricultural, and veterinary use. Available in pet flea products (Advantage) and termiticides (Premise). EPA pollinator risk assessment ongoing. Not classified as a human carcinogen. Regulatory |
| Canada | PMRA special review completed. Some outdoor uses cancelled or restricted. Available in veterinary flea products. Regulatory |
| International | Not IARC classified. WHO Class II (moderately hazardous). EU outdoor ban for pollinators. Worldwide debate on neonicotinoid impacts on bees and ecosystem services. Regulatory |
What it is
Imidacloprid is a chloronicotinyl insecticide that acts as an agonist at nicotinic acetylcholine receptors (nAChRs) in insect nervous systems. It has high selectivity for insect nAChRs over mammalian nAChRs, giving it relatively low mammalian toxicity. Bayer (now Bayer CropScience) introduced imidacloprid in 1991, and it quickly became the world's best-selling insecticide. IARC has not evaluated imidacloprid for carcinogenicity. The EPA has generally classified imidacloprid as not likely to be carcinogenic to humans based on available animal studies. The major regulatory controversy around imidacloprid centres on its toxicity to bees and other pollinators — the EU banned outdoor agricultural uses in 2018 based on EFSA risk assessments concluding unacceptable risk to bees.
Where it shows up in bedding
Imidacloprid enters the bedroom through two pathways. First, pets treated with imidacloprid-based flea products (Advantage, Seresto collars) transfer residues to bedding, pillows, and carpets when they sleep on or near the bed. Imidacloprid distributes across the pet's skin surface via the lipid layer and transfers to any surface the animal contacts. Second, homes with termite treatment systems (Premise contains imidacloprid) can have residues in household dust from the treated soil and building materials. For people who share beds with flea-treated pets, the pet pathway is the more significant bedroom exposure route.
Citations
- EFSA (2018). Neonicotinoids: risks to bees confirmed. EFSA News. Source Regulatory
- EPA. Imidacloprid — Pesticide Fact Sheet. Source Regulatory
- Coscolla, C. et al. (2017). Analysis of Currently Used Pesticides in Fine Airborne Particulate Matter (PM 2.5) by Pressurized Liquid Extraction and Liquid Chromatography. Journal of Chromatography A, 1200(2): 100-107. Source Peer-reviewed
Frequently asked questions
Does my dog's flea treatment contaminate my bed?
Yes. Pets treated with imidacloprid-based flea products (such as Advantage) transfer residues to surfaces they contact, including bedding, pillows, and carpets. The imidacloprid distributes across the pet's skin and fur via the lipid layer. If your pet sleeps on your bed, transfer to bedding is expected. The amounts are small relative to the dose applied to the pet and are not expected to cause health effects in humans, given imidacloprid's selectivity for insect over mammalian receptors.
Why was imidacloprid banned in the EU?
The EU banned outdoor agricultural uses of imidacloprid in 2018 based on EFSA risk assessments concluding that neonicotinoids posed an unacceptable risk to bees and other pollinators. The concern is environmental, not human health — imidacloprid has low mammalian toxicity but is highly toxic to bees. Indoor uses (including pet flea treatments) remain authorised because they do not expose pollinators.
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.