Specific Guidelines for Drain Disposal

We divide chemicals into three groups with regard to drain disposal in laboratories:

• Class A. Chemicals of little or no hazard in dilute aqueous solution. These solutions are suitable for disposal down the drain in quantities of up to about 100 g of solute per laboratory per day.
• Class B. Chemicals of moderate hazard in dilute aqueous solution. These solutions are suitable for disposal down the drain with excess water in quantities no greater than 1 g of solute per laboratory per day.
• Class C. Chemicals that may not be drain disposed in any amount except by written approval of the Hazardous Waste Management Committee. (The Office of Environment, Health and Safety should be contacted to obtain this approval.)