scope:

Description of Driving Event:

A glass container of chemical waste exploded when disposing of a new metal etching waste solution (mixed organic/acid chemical) using a 1-gallon glass container designated only for mixed waste acid and loosely fitted the cap. The waste solution was incompatible with at least one of the acids (Nitric, HNO3) in the waste container. A few minutes later, the employee heard a hissing noise and the container exploded. The explosion cast glass shrapnel and chemical waste across the laboratory, causing damage to laboratory equipment. Fortunately, the employee was not around the explosion and evacuated the laboratory without injury.

This was a routine process. However,

1. The new chemical etching solution (hydrochloric acid, ethanol, and copper chloride), was disposed of without review by the laboratory's chemical hygiene officer or the safety representative.

2. There was no pre-use hazard analysis, which may have prevented the mixing of incompatible chemicals.

3. Mixed waste acids were stored in a glass container (still a common practice in some chemical laboratories) instead of a compatible plastic container. This created the potential for additional hazards from a failure or explosion.