Heritage-Crystal Clean, Inc. 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. The Company 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 the Company's parts cleaning, containerized waste management, vacuum truck services, used antifreeze recycling activities and field services. The Oil Business segment consists of used oil collection activities, sale of recycled fuel oil, re-refining activities, and oil filter removal and disposal services. Through its re-refining process, the Company recycles used oil into lubricant base oil and by-products, and it is a supplier to firms that produce and market finished lubricants.