Soy What EM is a soybean-based safety solvent with an emulsifier so it will rinse off with water. This product effectively removes asphalt and tar from all types of equipment. Soy What EM is safe on most painted, plastic and glass surfaces and contains no hazardous materials. It biodegrades quickly once it is in the environment. Use Soy What EM straight, do not dilute. Spray or brush onto surface and allow product to dissolve and soften asphalt, then rinse with water or wipe down.