• Occupational health practice

Setting occupational exposure limits (OELs) for hazards in the workplace has been an integral component of worker health protection programs for many decades. These OELs have been established by many authoritative bodies around the world, such as the Threshold Limit Value Committee (TLV) of the American Conference of Governmental Industrial Hygienists (ACGIH). The traditional approach has been to develop OELs by expert review of the available evidence, and set levels based primarily on health considerations. OELs, such as the TLVs, are usually used to guide occupational health practitioners in the assessment and control of workplace hazards, although some regulatory authorities use OELs as legal standards.

OELs have been criticised for not protecting all workers as, for example, the ACGIH states that TLVs represent conditions under which nearly all workers may be repeatedly exposed without adverse health effects. Another criticism is that OELs have only been set for a small fraction of the hazards to which workers can be exposed. A third criticism is that expert judgement is not a rigorous enough method for setting robust OELs and can quickly get out of date.1 Despite these criticisms, OELs have continued to be a major source of guidance for hazard control in workplaces …