: Garden Safe Brand Insecticidal Soap Insect ...- plants safe liquid soaps ,1. Potassium Salts of Fatty Acids, the active ingredients in Garden Safe(R) Brand Insecticidal Soap Insect Killer, are made from plant-derived sources. 2. The active ingredients damage the cell membranes of many soft-bodied insects, such as aphids, whiteflies and mites, killing them through contact. : Garden Safe Brand Insecticidal Soap Insect ...1. Potassium Salts of Fatty Acids, the active ingredients in Garden Safe(R) Brand Insecticidal Soap Insect Killer, are made from plant-derived sources. 2. The active ingredients damage the cell membranes of many soft-bodied insects, such as aphids, whiteflies and mites, killing them through contact.