From biomonitoring studies to lowered occupational exposure limits for hexavalent chromium

Occupational exposure to the carcinogen hexavalent chromium [Cr(VI)] occurs during stainless steel production, welding, and chrome plating. Two sister-projects, SafeChrom and SAM-Krom, were initiated in Sweden and Denmark, respectively, to inform stakeholders, decision-makers and regulators on current occupational exposure to Cr(VI), and preventive measures prior to revision of national occupational exposure limits (OELs) for Cr(VI). Both studies were cross-sectional, involving exposed workers and controls. Cr(VI) exposure was assessed as inhalable Cr(VI), urinary Cr and Cr(VI) content in red blood cells. Both studies found increased air Cr(VI) concentrations associated with increased levels of urinary Cr and Cr(VI) in red blood cells. Air levels of Cr(VI), urinary Cr and blood levels of Cr(VI) were highest among Danish chrome platers. Furthermore, Cr(VI) exposure levels exceeding Danish OEL were found for trainees performing welding at a vocational school. Interviews with managers at Swedish workplaces indicated that OELs have an important role as baseline for acceptable exposures, but revealed low awareness of the socio-economic trade-offs for the Cr(VI) OELs. The two studies enabled evidence-based decision-making resulting in lower Cr(VI) OELs in Denmark and Sweden in 2025–2026, highlighting the value of a coordinated Nordic collaboration and stakeholder engagement in supporting evidence-based regulation.