However, because of its toxicity, it has either been removed from the market or is restricted. Tobacco teas are sometimes prepared by home gardeners to control garden pests, and while not as toxic as nicotine sulfate sprays, any nicotine solution toxic enough to kill insects can also be harmful to humans. Certain natural chemicals such as sulfur are effective as pesticides. Sulfur is used by itself or in a mix with other pesticides to control plant diseases and spider mites. Once sprayed on a plant, sulfur oxidizes to become sulfur dioxide, a toxic fume that disrupts the metabolic processes of target pests, which absorb it and try to use it in place of oxygen.
Elemental sulfur is available as wettable sulfur and liquid sulfur.
Sulfur is also packaged as an important component of other pesticides, such as lime sulfur. Lime sulfur may help control spider mites, but the primary purpose of adding lime to sulfur is to enhance its effectiveness as a fungicide. Sulfur is also sold in blends with copper, and as bordeaux mix, which is copper sulfate and hydrated lime. Products containing sulfur and copper are designed for use against diseases. Sulfur is also often sold in a mix with dormant oil to control plant diseases and insects.