NIOSH Health Hazard Evaluation A Health Hazard Evaluation (HHE) is a study of a workplace. It is done to learn whether workers are exposed to hazardous materials or harmful conditions. At no cost to employers or employees, or their representatives, the NIOSH HHE program may be able to help with a variety of workplace health and safety issues. This site lets you know about the program and how to ask for NIOSH help. It also has links to reports from thousands of HHEs done by NIOSH.