ChromAir is designed to detect exposure dose levels to specific toxic chemicals. Because it relies on diffusion, there is no pump to operate. The patented design provides immediate and accurate results throughout the sampling period. The ChromAir chemical exposure monitoring badge offers six exposure levels, with most indicating from one-tenth to two times the Permissible Exposure Limit (PEL) Time Weighted Average (TWA) for an eight-hour work period. To determine the average concentration, users can locate the highest cell with a color change and divide the corresponding dose level (parts per million times hour) by the sampling time in hours.