What's actually in conventional pest sprays
Conventional sprays use bifenthrin, cypermethrin, chlorpyrifos, and piperonyl butoxide — three EPA Group C possible carcinogens and one organophosphate banned in the EU for developmental neurotoxicity. None are necessary to control household pests.
- Bifenthrin & cypermethrin: synthetic pyrethroid nerve agents, EPA Group C possible carcinogens.
- Chlorpyrifos: organophosphate banned by the EU in 2020 for developmental-neurotoxicity concerns.
- Piperonyl butoxide: not even an insecticide — a synergist that disables the liver's detox enzymes.
- Essential oils + castile soap cover the same target pest list, with FDA-GRAS / EPA minimum-risk ingredients.
The pest control industry has a transparency problem.
The active ingredients in conventional sprays are listed on the label — technically. But they’re listed by chemical name, in font small enough to require reading glasses, after a paragraph of warnings most people skip. The assumption is that you won’t look them up.
Here’s what four of the most common ones actually are.
Bifenthrin
Found in: Raid Multi-Insect Killer, Ortho Home Defense, dozens of others.
Classified by the EPA as a possible human carcinogen, Group C — meaning there is possible evidence of carcinogenic potential. It’s a synthetic pyrethroid: a laboratory-manufactured compound designed to attack the sodium channels in insect nervous systems. Recent data show pyrethroids may have adverse effects on fertility, immune function, cardiovascular function, and hepatic metabolism. Highly toxic to aquatic invertebrates. Labels include instructions not to allow runoff near waterways. It leaves a residual on surfaces for weeks after application.
Cypermethrin
Found in: Raid Max, many professional pest control formulas.
Same chemical family as bifenthrin. Same mechanism. Clinical studies on patients acutely intoxicated with cypermethrin documented a wide range of symptoms — and the formulation containing cypermethrin was found to be more toxic than the active ingredient alone, attributable to the adjuvants and their interactions. The EU requires specific disposal protocols for containers because the residual is classified as an environmental hazard.
Chlorpyrifos
Found in: professional exterminator formulas, some consumer products.
An organophosphate — the same chemical family as nerve agents used in warfare, though at far lower concentrations. Chlorpyrifos has been connected to negative effects on neurodevelopment, particularly in young infants. The European Union banned chlorpyrifos in 2020 because of developmental neurotoxicity concerns. The Massachusetts Attorney General sued the EPA to ban it. Epidemiological studies show neurological damage to prenatal development, infants, and children.
Piperonyl Butoxide
Found in: almost every conventional spray as a “synergist.”
This one isn’t even the insecticide. Its job is to disable the enzyme systems — in the insect and in you — that would otherwise break down the active chemicals. It makes the other ingredients last longer and work harder by overwhelming the liver’s detoxification pathway. Also classified by the EPA as a Group C possible human carcinogen.
None of these compounds are necessary
The peer-reviewed literature on essential oils and castile soap covers the same target pest list — ants, roaches, spiders, wasps, mosquitoes, ticks, fleas — using ingredients that have been used safely in food, medicine, and cosmetics for centuries. The kill mechanisms are documented in the Journal of Medical Entomology, Environmental Entomology, USDA Agricultural Research Service publications, and the National Institutes of Health’s own database.
Pesticide residues on surfaces don’t stay on the surface. They aerosolize. They settle on dust. They transfer to skin, food, and pet fur. Every time you spray a conventional product in your home, you’re choosing to accept that exposure for yourself and everyone in the building.
You don’t have to. The alternative works.