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
- Plant oils and other listed minimum-risk ingredients (peppermint oil, rosemary oil, cedarwood oil, geraniol, 2-phenylethyl propionate, castor oil, sodium lauryl sulfate) (CAS 8006-90-4 (peppermint oil); 8000-25-7 (rosemary oil); 8000-27-9, 68990-83-0 and 85085-29-6 (cedarwood oil: Virginia, Texas, China); 106-24-1 (geraniol); 122-70-3 (2-phenylethyl propionate); 8001-79-4 (castor oil); 151-21-3 (sodium lauryl sulfate))
- Chemical class
- Plant essential oils (peppermint, rosemary and cedarwood oil), the compounds geraniol and 2-phenylethyl propionate, castor oil of U.S. Pharmacopeia grade or equivalent, and sodium lauryl sulfate, all listed in Table 1 of 40 CFR 152.25(f).[1]
- Mode of action
- Repellent and contact action: UC IPM says peppermint and rosemary oils may repel insects, mites or vertebrate pests and can kill insects and mites by blocking their breathing structures[4][5]
- Registration
- None: exempt from federal registration as a minimum-risk pesticide (40 CFR 152.25(f)); no EPA signal word.[1]
What a lab test of bed bug products found
Rutgers University entomologists tested nine essential oil-based products and two detergent products against bed bugs in the laboratory, alongside two conventional insecticides. Only two of the 11 killed more than 90 percent of nymphs when sprayed directly and in forced-exposure tests on treated surfaces: one with 1% geraniol, 1% cedar extract and 2% sodium lauryl sulfate, and one with 0.003% clove oil, 1% peppermint oil and 1.3% sodium lauryl sulfate.[6]
Both were significantly less effective than the conventional insecticides in a choice-exposure test, and neither showed detectable repellency. The geraniol product killed 87 percent of eggs it was sprayed on directly, while the other non-synthetic products had little effect on eggs. The authors called the two products potentially useful but said they still need testing in real infestations.[6]
Castor oil and moles
The Internet Center for Wildlife Damage Management rates castor oil repellents as minor in effect. A liquid product has to be watered in well: irrigate with 1/2 inch of water before applying and follow with at least 1 inch. Areas that get heavy irrigation lose the repellent quickly to leaching, and early studies of granular castor oil products found them less effective than liquids.[8]
Spray the whole area you want protected, because moles may burrow under a treatment applied only around the edge.[8]
Claims these products can't make
A minimum-risk product may say it controls ticks or mosquitoes, but it may not claim to control ticks that carry Lyme disease or mosquitoes that can transmit malaria, encephalitis, West Nile virus or Zika virus. It also can't claim to control microorganisms that threaten human health.[2][1]
Every active ingredient must be on the rule's list, with its percentage by weight shown on the label, and every inert ingredient must come from the permitted list. The label must give the company's name, street address and phone number.[1]
Because EPA does not review these products, a label line such as 'Recommended by EPA as safe and exempt' is misleading, and EPA gives 'chemical-free' and 'kills all insects' as examples of statements that may be false or misleading. Many states require minimum-risk products to be registered with the state.[2][3]
Where it is used
UC IPM describes peppermint oil and rosemary oil as insecticides derived from those plants that may repel insects, mites or vertebrate pests, and that can kill insects and mites when the oil blocks their breathing structures. Its Pest Notes mention peppermint oil for ants and rosemary oil for ants and spider mites.[4][5]
UC IPM's examples of home-use products include a bat repellent and a wasp and hornet killer containing peppermint oil, and a deer repellent and a vegetable garden insect killer containing rosemary oil.[4][5]
Natural cedar blocks, chips, balls, chests and drawer liners made entirely of untreated cedar are exempt under a separate rule, but only when they claim to repel arthropods other than ticks or to retard mildew. That exemption doesn't cover cedar oil or formulated products containing it; cedarwood oil is listed separately as a minimum-risk active ingredient.[1]
Castor oil is the usual active ingredient in mole repellents. UC IPM says research has shown some effect on eastern moles but none has been published for moles in the western United States, and repelled moles may simply move to neighboring lawns and gardens.[7]
Safety and environmental hazards
People
NPIC notes that plant oils can be harmful to the eyes, that some people are allergic to them, and that no matter how natural, all pesticides should be used with care. EPA does not review minimum-risk products, and UC IPM's database has not yet published acute or chronic toxicity ratings for peppermint oil or rosemary oil.[3][2][4][5]
Pets
Because EPA does not review minimum-risk products, there is no EPA-reviewed pet hazard statement for them. NPIC's general advice is to follow the label and take steps to minimize exposure to people, animals and the environment.[2][3]
Bees and pollinators
UC IPM's database lists the honey bee ratings for peppermint oil and rosemary oil as information still to be added, and minimum-risk products are not reviewed by EPA, so there is no published bee rating to go by.[4][5][2]
Fish and water
UC IPM has not yet published water-quality ratings for peppermint oil or rosemary oil. NPIC's advice for any pesticide, however natural, is to follow the label and limit exposure to the environment.[4][5][3]
Common questions
- Do peppermint oil sprays get rid of bed bugs?
- Lab results are mixed. In a Rutgers test of 11 non-synthetic bed bug products, only two killed more than 90 percent of nymphs, one of them a spray with 1% peppermint oil, clove oil and sodium lauryl sulfate, and both were less effective than conventional insecticides in a choice test. The researchers said testing in real infestations is still needed.[6]
- Why doesn't my essential oil insect spray have an EPA registration number?
- Products made only from ingredients on EPA's minimum-risk lists, such as peppermint, rosemary or cedarwood oil, are exempt from federal registration if they meet every condition in 40 CFR 152.25(f). EPA doesn't review them, and many states require them to be registered with the state.[1][2][3]
- Does castor oil keep moles away?
- Only somewhat. UC IPM says castor oil repellents have shown some effect on eastern moles, and the Internet Center for Wildlife Damage Management calls the effect minor. Liquid products have to be watered in well, and repelled moles may just move next door.[7][8]
- Are essential oil pesticides safe around kids and pets?
- Use them with care. NPIC says that no matter how natural, all pesticides should be used with care, that plant oils can be harmful to the eyes and that some people are allergic to them. EPA does not review these products, so follow the label and keep exposure to people and animals low.[3][2]
Sources
- Electronic Code of Federal Regulations, “40 CFR 152.25, Exemptions for pesticides of a character not requiring FIFRA regulation (paragraph (e) natural cedar; paragraph (f) minimum risk pesticides).” www.ecfr.gov/current/title-40/chapter-I/subchapter-E/part-152/subpart-B/section-152.25 (accessed 2026-11-08)
- U.S. EPA, “Conditions for Minimum Risk Pesticides.” www.epa.gov/minimum-risk-pesticides/conditions-minimum-risk-pesticides (accessed 2026-11-08)
- National Pesticide Information Center, “Minimum Risk Pesticides.” npic.orst.edu/ingred/ptype/minrisk.html (accessed 2026-11-08)
- University of California Statewide IPM Program, “Home and Landscape Pesticide Active Ingredients Database: peppermint oil.” ipm.ucanr.edu/home-and-landscape/pesticide-active-ingredients-database/active-ingredient-details/?uaiKey=46 (accessed 2026-11-08)
- University of California Statewide IPM Program, “Home and Landscape Pesticide Active Ingredients Database: rosemary oil.” ipm.ucanr.edu/home-and-landscape/pesticide-active-ingredients-database/active-ingredient-details/?uaiKey=55 (accessed 2026-11-08)
- Journal of Economic Entomology (N. Singh, C. Wang and R. Cooper, Rutgers University), “Potential of Essential Oil-Based Pesticides and Detergents for Bed Bug Control, J. Econ. Entomol. 107(6):2163-2170 (2014).” doi.org/10.1603/EC14328 (accessed 2026-11-08). Abstract read via PubMed (PMID 26470082).
- University of California Statewide IPM Program, “Pest Notes: Moles, UC ANR Publication 74115.” ipm.ucanr.edu/home-and-landscape/moles/ (accessed 2026-11-08)
- Internet Center for Wildlife Damage Management, “Mole Damage Prevention and Control Methods.” icwdm.org/species/other-mammals/moles/mole-damage-prevention-and-control-methods/ (accessed 2026-11-08)