Clean Harbors is North America's leading provider of environmental and industrial services, including hazardous waste disposal, emergency spill response, industrial cleaning and used-oil re-refining through its Safety-Kleen business. Founded in 1980 by Alan McKim and headquartered in Norwell, Massachusetts, it is listed on the NYSE (CLH), has about 25,000 employees and more than $6 billion in annual revenue, and is led by co-CEOs Michael Battles and Eric Gerstenberg.