POR-15® Fuel Tank Sealer was formulated and developed in our own laboratories due to the demand for a high-tech sealer impervious to all fuels, including the new Stage II fuels which have a high alcohol content. POR-15® Fuel Tank Sealer has superior strength and fuel resistance, and does not contain Methyl Ethyl Ketone, a highly flammable and deadly carcinogen (cancer-causing). POR-15® Fuel Tank Sealer is non-flammable and is environmentally safe.