These are flammable and toxic in varying degrees. Most proprietary grease stain removers contain a solvent called trichloroethane, which is non-flammable and less toxic than other solvents. Spot-removers are usually based on perchloroethylene, a nonflammable solvent which should be applied in a well-ventilated room or out of doors. Used near heat, it gives off dangerous vapours. The symbol P on a clothes-care label means that the garment should be cleaned with a perchloroethylene based dry-cleaning solvent.
Alternative
Acetic acid (white vinegar) and citric acid (lemon juice) can be used to take out some stains. Try softening tar and oil with mayonnaise or butter. Fuller's earth, a clay mineral, will absorb grease from un-washable items such as felt, suede and fur.
