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
- Potassium salts of fatty acids (potassium laurate in Safer concentrate)
- Chemical class
- Fatty-acid soap; a broad-spectrum contact pesticide that, depending on the product, is formulated as an insecticide, miticide, herbicide or fungicide.[1]
- Mode of action
- Physical action on contact: penetrates the exoskeleton and dehydrates the insect[1]
- Signal word
- Safer Insecticidal Soap Concentrate (Safer Brand Insect Killing Soap): Warning[2]
How it works
The fatty-acid salts penetrate the insect's outer shell and cause dehydration and death; as an herbicide, soap works by blocking photosynthesis.[1]
Because it acts only on contact, the label stresses wetting all infested surfaces thoroughly and spraying earwigs directly after disturbing their hiding places.[2][1]
Getting it to work
Spray when insects or their damage first appear, check aphids again after two days, and time a second spray to catch newly hatched young.[2]
For the crawler stage of adelgids, psyllids and scales on landscape trees and shrubs, spray to wet the bark and leaves.[2]
Where it is used
Do not use it on new transplants, newly rooted cuttings or drought-stressed plants, or when the temperature is above 90°F.[2]
Do not spray bleeding heart, gardenias, jade plant, lantana or sweet peas, or crown of thorns indoors; some azaleas, begonias, camellias, fuchsias and impatiens are soap-sensitive, and if plants wilt within a few hours, rinse them with clean water.[2]
It may be used up to and including the day of harvest on fruits and vegetables.[2]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Safer Insecticidal Soap Concentrate (Safer Brand Insect Killing Soap)[2] | Safer, Inc. (Woodstream) | 42697-1 | 49.52% | liquid concentrate | Warning |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Safer Insecticidal Soap Concentrate (Safer Brand Insect Killing Soap) | Houseplants, flowers, roses, trees, shrubs, fruits and vegetables | Aphids, mealybugs, mites, whiteflies, scale crawlers, thrips, earwigs and tent caterpillars | 2.5–4.0 fl oz per gal of water[2] 2.5 fl oz (5 Tbsp) per gallon for most uses, 4 fl oz (8 Tbsp) for tent caterpillars. Use soft water and freshly mixed spray. Repeat weekly up to three times; no more than 3 applications in two weeks. |
How to apply it, step by step
1. Protective gear
- Wear goggles or safety glasses: the concentrate carries a WARNING because it can cause substantial but temporary eye injury, and it irritates skin.[2]
- Keep it off your skin and clothing, and wash with soap and water after handling.[2]
2. Before you spray
- Don't spray new transplants, newly rooted cuttings or plants stressed by drought, and don't spray when it's above 90°F.[2]
- Use soft water if you can, and mix a fresh batch for each use; the concentrate is flammable, so keep it away from heat and open flame.[2]
3. Mixing
- Shake well, then mix 1 part concentrate with 50 parts water, which is 2.5 fl oz (5 tablespoons) per gallon, unless the label gives another rate for your plant.[2]
4. Applying
- Spray when insects or their damage first appear, thoroughly wetting all surfaces of the infested leaves and branches; the soap only works on insects it actually wets.[2]
- For aphids, check the plants two days later and spray again if needed; for other pests, repeat weekly (every 7 to 10 days) as needed, up to three times.[2]
- Don't make repeated sprays close together without rinsing the foliage between them.[2]
5. After you spray
- It may be used up to and including the day of harvest.[2]
First aid
- In the eyes, hold them open and rinse slowly and gently with water for 15 to 20 minutes, removing contact lenses after the first 5 minutes; on skin or clothing, take off contaminated clothing and rinse skin for 15 to 20 minutes.[2]
- If inhaled, move the person to fresh air and call 911 if they aren't breathing; the label also lists the National Pesticide Information Center, 1-800-858-7378.[2]
Storage, spills and disposal
Safety and environmental hazards
People
The concentrate carries the signal word WARNING: it causes substantial but temporary eye injury and skin irritation and is harmful if inhaled or absorbed through the skin, so wear goggles when mixing.[2]
Pets
The label says to store it out of reach of children and pets and out of direct sunlight.[2]
Bees and pollinators
This label carries no bee or environmental hazard statement; soap works only on insects it wets directly, because it is a contact pesticide.[2][1]
Fish and water
The Safer concentrate label has no aquatic toxicity statement; use the spray only on the plants being treated.[2]
Common questions
- How much insecticidal soap per gallon?
- Safer's concentrate label calls for 2.5 fluid ounces (5 tablespoons) per gallon of water for most uses, and 4 ounces for tent caterpillars.[2]
- Can insecticidal soap burn plants?
- Yes, on sensitive plants. The label lists plants not to spray and says to avoid spraying above 90°F or on drought-stressed plants.[2]
- Can I spray soap on vegetables the day I pick them?
- Yes. The label allows use up to and including the day of harvest.[2]
Sources
- University of California Statewide IPM Program, “Home and Landscape Pesticide Active Ingredients Database: potassium salts of fatty acids.” ipm.ucanr.edu/home-and-landscape/pesticide-active-ingredients-database/active-ingredient-details/?uaiKey=50 (accessed 2026-10-06)
- U.S. EPA Pesticide Product Label System, “Safer Insecticidal Soap Concentrate label, EPA Reg. No. 42697-1 (EPA-stamped, Nov. 18, 2009).” www3.epa.gov/pesticides/chem_search/ppls/042697-00001-20091118.pdf (accessed 2026-10-06)