In their effort to evaluate selected chemicals from the 2021, 2022, 2023, and 2024 threshold limit value (TLV) – time-weighted average (TWA) document published by the American Conference of Governmental Industrial Hygienists (ACGIH), the WorkSafeBC Exposure Limit Review Committee (ELRC) tasked the Evidence-Based Practice Group (EBPG) to investigate the health effects, regarding to the development of lung cancer and/or other non-cancer lung diseases, of occupational exposure to antimony trioxide (Sb₂O₃) with a significant lowering of the TLV-TWA. In their 2021 publication, the ACGIH lowered the TLV-TWA of (Sb₂O₃) to 0.02 mg/m³ from a previous level of 0.5 mg/m³ in 1978/1979. In their documentation¹, the ACGIH stated that this lowering in the TLV-TWA of (Sb₂O₃) was expected to protect against non-malignant and malignant lung effects.