Safer Insect Killing Soap Concentrate, 1 gal, case of 4The Safer Brand insect killing soap utilizes the power of potassium salts of fatty acids (insecticidal soap). The potassium salts weaken the insect's waxy protective outer shell. Apply every 7 10 days when insects are present or as needed to prevent further damage. Safer Brand Insect Killing Soap is highly preferable to chemical pesticides, who possess toxins that can kill beneficial insects and cause long term detrimental effects on the environment.