Pesticide actives

What the research says

A flea and tick product is a pesticide, and the EPA makes it print an ingredient statement: every active by name and percentage, with the rest totalled underneath. The actives are named more precisely than on any other label we read. The rest, often most of the product, is usually one unnamed share ("Other ingredients 90%"), and we flag that line the way we flag any line that names nothing: as Undisclosed material, a caution about the missing names, not a known hazard. A minimum-risk product, the kind exempt from registration, has to name its inert ingredients, and then we read them like any other list.

We flag the actives on every product in the category, not because a particular one is dangerous, but because "natural" and "chemical" are not the useful distinction here. Cinnamon, clove and cedarwood oils kill insects by the same logic as a synthetic pyrethroid, and cats in particular metabolize several essential oils and permethrin poorly. Dose, species and directions are what matter, so the note on each product names its actual actives and what they are.

Read the species on the front. A permethrin product labelled for dogs can be fatal to a cat in the same house, and several essential-oil formulas that are fine on a dog are not labelled for cats either. Nothing about this flag says avoid the category: an untreated flea infestation carries its own real risks.