Objectives:Currently, there is only limited knowledge regarding the hazard of low-level exposure to CMR materials in workplaces. To overcome this limitation, a reference concentration for workers (RfC_w) from among the risk assessment tools proposed by the US EPA is widely used to set a provisional workplace exposure level (PWEL) for CMR materials for which there are no established Korea Occupational Exposure Limits (KOELs) or subjective chemicals for work environment measurements as regulated by Korea Ministry of Employment and Labor (KMOEL). A simple European calculator of derived no effect level (SECO-DNEL) as proposed by REACH can also be used in place of RfC_w to set the PWEL for chemicals. This study was performed to test the acceptability of using SECO-DNEL as an alternative to RfC_w when setting a PWEL for low-level exposures. Methods: The RfC_w and DNEL for the five CMR materials of dinitrogen oxide, catechol, 2-phenoxy ethanol, carbitol, and carbon black were calculated using the dose-response assessments of the US EPA for RfC_w and REACH guidance for SECO-DNEL, respectively. They were compared using paired t-tests to determine the statistical differences between them. Results: For the five chemicals, the RfC_w were 2.53 ppm, 0.10 ppm, 1.73 ppm, 1.66 ppm, and 0.05 mg/㎥, respectively, while the SECO-DNEL were 2.01 ppm, 0.11 ppm, 1.83 ppm, 1.77 ppm, 0.14 mg/㎥, respectively. There was no statistically significant difference between RfC_w and SECO-DNEL. Conclusions: This study suggests that the SECO-DNEL could be applied in place of RfC_w to set a PWEL for low-level exposure to chemicals, especially CMR materials. To further ensure the reliability of SECO-DNEL as an alternative tool, more chemicals should be applied for calculation and comparison with RfC_w.