The label is the law. Read your product's label before you mix or apply; the rates here come from the labels listed under Sources.
- Active ingredient
- Boric acid (CAS 10043-35-3)
- Chemical class
- Inorganic borate; boric acid and borax differ in how much boron they contain, and their toxicity tracks that boron content.[1]
- Mode of action
- IRAC Group 8D: Miscellaneous non-specific (multi-site) inhibitors: borates[3]
- Signal word
- Harris Famous Roach Powder (Harris Boric Acid Roach Powder with Lure): Caution[2]
How it works
Insects die after eating boric acid: it disrupts their stomach, can affect the nervous system, and can scratch and damage their outer shell.[1]
Boric acid is IRAC Group 8D, a multi-site inhibitor, which is a different mode of action from the Group 3A pyrethroid sprays.[3]
Where the label says to put it
Under and behind the refrigerator, stove, sink, dishwasher, washer, dryer and tubs; into cracks along baseboards and cabinet corners; and into the voids around pipes, drains and electrical conduits.[2]
For cabinets, the label allows drilling half-inch holes in the kick panels beneath kitchen and bathroom cabinets and dusting into the void, or dusting drawer wells after pulling out the lower drawers.[2]
Any powder still visible after treatment should be brushed into cracks and crevices or cleaned up, and the treatment repeated as needed.[2]
In soil and water
Boric acid occurs naturally in soil, water and plants; it dissolves in water and under some soil conditions can reach groundwater, and too much boron can harm plants, especially citrus, stone fruit and nut trees.[1]
Where it is used
The Harris powder is labeled for ants, palmetto bugs, cockroaches, silverfish and water bugs indoors, and contains a lure so the insects eat it.[2]
Do not use it in edible product areas of restaurants and food plants, or in serving areas while food is out.[2]
Spoons and measuring cups used to apply it must never go back to food use.[2]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Harris Famous Roach Powder (Harris Boric Acid Roach Powder with Lure)[2] | P.F. Harris Manufacturing Company, LLC | 3-10 | 99.0% | dust | Caution |
How to apply it, step by step
1. Protective gear
- Avoid getting the powder in your eyes or on your clothing and avoid breathing the dust; it is harmful if swallowed or inhaled and moderately irritating to the eyes.[2]
- Wash thoroughly with soap and water after handling, and wash contaminated clothing before wearing it again.[2]
2. Before you spray
- Apply it only where children and pets can't reach it, and keep it away from food and animal feed.[2]
- Use a dedicated spoon: don't use teaspoons or measuring cups for food after using them with insecticide.[2]
- Shake the container well before opening it.[2]
3. Mixing
- No mixing: it is applied dry, straight from the container, with the puffer applicator or a spoon.[2]
4. Applying
- Lay a light barrier the insects must crawl through: under and behind the refrigerator, stove, sink, dishwasher, washer, dryer and tubs, and into cracks and crevices along baseboards and the corners of cabinets and closets.[2]
- Dust a line along the back of kitchen cabinets, into drawer wells after pulling out the lower drawers, under bookshelves, and into openings around plumbing, drains and electrical conduits; the label also allows drilling ½-inch holes in the kick panels beneath cabinets and dusting inside.[2]
- The added lure gets roaches, ants and silverfish to eat the powder, which is how it works.[2]
5. After you spray
- Brush any visible powder into cracks and crevices or clean it up, and reapply as needed.[2]
First aid
- If swallowed, call a poison control center or doctor immediately, have the person sip a glass of water if able, and don't induce vomiting unless told to; if inhaled, move the person to fresh air and call 911 if they aren't breathing.[2]
- In the eyes, rinse slowly and gently with water for 15 to 20 minutes, removing contact lenses after the first 5 minutes. The label's emergency and information line is 1-800-858-7378.[2]
Storage, spills and disposal
Safety and environmental hazards
People
The label signal word is CAUTION: harmful if swallowed or inhaled and causes moderate eye irritation. Boric acid is low in toxicity when eaten or touched, but people who swallowed it have had nausea, vomiting, stomach pain and diarrhea, and infants who ate large amounts have had convulsions; EPA concluded it is not likely to cause cancer.[2][1]
Pets
The label says to apply it only where children and pets cannot get to it and to store it out of their reach. Animals that eat boric acid can show signs of poisoning within 2 hours.[2][1]
Bees and pollinators
EPA concluded that boric acid is relatively nontoxic to bees.[1]
Fish and water
Boric acid is slightly toxic to practically non-toxic to freshwater fish, practically non-toxic to frogs, toads and water fleas, and practically non-toxic to birds.[1]
Common questions
- Is boric acid safe around kids and pets?
- It is low in toxicity, but not harmless: the label requires putting it only where children and pets cannot reach, and infants who swallowed large amounts have had seizures.[2][1]
- Does boric acid cause cancer?
- EPA concluded that boric acid is not likely to be carcinogenic to humans; two-year feeding studies in mice and rats found no evidence that boric acid or borax causes cancer.[1]
- Can I use boric acid in my kitchen?
- Yes, in a home kitchen, under and behind appliances and in cracks and voids, kept off food and food-handling surfaces.[2]
Sources
- National Pesticide Information Center, “Boric Acid General Fact Sheet.” npic.orst.edu/factsheets/boricgen.html (accessed 2026-10-06)
- U.S. EPA Pesticide Product Label System, “Harris Famous Roach Powder label, EPA Reg. No. 3-10 (EPA-stamped, Mar. 9, 2021).” www3.epa.gov/pesticides/chem_search/ppls/000003-00010-20210309.pdf (accessed 2026-10-06)
- Insecticide Resistance Action Committee, “IRAC Mode of Action Classification Scheme, Version 11.5 (Feb. 2026).” irac-online.org/documents/moa-classification/ (accessed 2026-10-06)