Prediction of duration limited exposure for participants wearing chemical protective clothing in the cold.

The suitability of the IREQ (insulation required) index for predicting the thermal responses of 6 participants wearing chemical protective clothing was tested during exercise at -20 and -25 degrees C. IREQ was used to calculate duration limited exposure (DLE). Measured DLE correlated (r =0.899, p <0.001) with the predicted DLE. In exposures exceeding 40 min, however, the predicted DLE tended to be 10-20 min too short compared to the measured one. During short exposures the prediction was 5-20 min too long. The results show that IREQ overestimated the cold strain in participants wearing chemical protective clothing during cold exposures longer than 40 min. Nevertheless, predicted DLE never exceeded measured times and thus the prediction was always safe from the occupational point of view.