Establishment of Occupational Exposure Limit for Warfarin in China

This study aims to establish the occupational exposure limit （OEL） in the air for workplace of warfarin based on the available toxicological studies and field investigations by using questionnaire and air monitoring. The clinical therapeutic dose was used as lowest observed effect level （LOEL）, and no observed effect level （NOEL） was achieved by using a safety factor. The highest concentration of warfarin monitored in the worksite of centrifuge washing, drying and packing were 0.029 mg/m3, 0.052 mg/m3 respectively, which did not exceed the OEL 0.2 mg/m3 recommended by NIOSH and ACGIH. Considering its feasibility for enforcement and protection for workers, we recommend OEL 0.2 mg/m3 of warfarin in China.