Heritage-Crystal Clean provides full-service parts cleaning, containerized waste management, used oil collection, vacuum truck services and antifreeze recycling. The Company owns and operates a used oil re-refinery. It operates through two segments: Environmental Services and Oil Business. The Company provides hazardous and non-hazardous waste services to small and mid-sized customers in both the manufacturing and vehicle maintenance sectors. The Environmental Services segment consists of its parts cleaning, containerized waste management, vacuum truck, antifreeze and field services. The Company's services allow its customers to outsource their handling and disposal of parts cleaning solvents, as well as other hazardous and non-hazardous waste. The Oil Business segment consists of used oil collection activities, sale of recycled fuel oil and re-refining activities. Through its re-refining process, the Company recycles used oil into lubricant base oil and by-products.