Development of a cancer-based chronic inhalation reference value for hexavalent chromium based on a nonlinear-threshold carcinogenic assessment

► Nonlinear-threshold carcinogenic assessments should be considered for CrVI. ► A health-protective, cancer-based chronic ReV of 0.24 μg CrVI/m3 was derived. ► Chronic ReV is 300 times the EPA URF-based 1E-05 excess risk air concentration. ► The ReV will ultimately be compared to the 1E-05 air level based on TCEQ's URF.