As summer heat intensifies, OSHA’s focus on preventing heat related illness intensifies. With this intensity, many employers are going hi-tech to collect “heat exposure data” to establish work practices based on exposures. I have seen a recent increase in advertising for devices that can measure wet-bulb temperatures in workplaces and they are tying these reading back to complying with OSHA’s Heat Illness Prevention efforts. Portable heat stress meters or monitors are used to measure heat conditions. These instruments can calculate both the indoor and outdoor WBGT index according to established ACGIH Threshold Limit Value equations. With this information and information on the type of work being performed, heat stress meters can determine how long a person can safely work or remain in a particular hot environment. Officially OSHA’s program is targeted toward “outdoor workers”, but factory workers can be at even greater risks due to poor working conditions such as non-existent ventilation and the need to wear semipermeable or impermeable protective clothing. I also need to point out that OSHA does NOT have any heat exposure limits, but they will enforce the ACGIH TLV’s. Here’s the thing… if you are using one of these Wet-Bulb measuring devices to measure employee’s working conditions related to heat and humidity, then these “samples” will in fact fall under 1910.1020(d)(1)(ii) and must be retained as “exposure records” for 30 years. Here is OSHA’s position…