Xylene distillation
University of Washington

A large volume of xylene is used daily by the Pathology department for tissue staining processes. After the xylene is used, it is designated as hazardous waste and would normally have to be collected by Environmental Health & Safety (EH&S) for disposal via incineration. Through the xylene distillation program, EH&S instead collects the xylene for distillation and reuse. EH&S is able to distill the used xylene to a level of purity that matches that of virgin product. The xylene is then returned to the Pathology department for reuse in the same processes. By distilling and reusing discarded xylene, EH&S is able to divert what would otherwise be a large volume of hazardous waste, as well as save the Pathology department a large amount of money that would otherwise be spent on virgin product. In the past three years, EH&S has distilled and reused over 1,000 gallons of xylene per year. This has saved the Pathology department over $40,000 per year on product cost, and has saved EH&S nearly $1,500 on disposal costs.

Fun Facts: 
Virgin xylene costs $50/gal; distilled xylene only costs $10/gal!
Distillation avoids the generation over 1,000 gallons of hazardous waste that would require incineration
Project Contact Name: 
Mark Volkert
(206) 616-5835