Side-by-Side Comparison of Field Monitoring Methods for Hot Bitumen Emission Exposures: The German IFA Method 6305, U.S. NIOSH Method 5042, and the Total Organic Matter Method

Abstract

Field studies were conducted at paving and roofing sites to compare the German Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) Fourier transform infrared spectroscopy method 6305 with the National Institute for Occupational Science and Health (NIOSH) benzene soluble fraction method 5042 plus total organic matter. Sampling using both methods was performed in multiple bitumen-related workplace environments. To provide comparable data all samplings were performed in parallel, and the analytical data were related to the same representative bitumen condensate standard. An outline of the differences between the sampling and analytical methods is provided along with comparative data obtained from these site investigations. A total of 55 bitumen paving sampler pairs were reported and statistical comparisons made using the 35 pairs of detectable data. First, the German inhalable aerosol data and the NIOSH benzene soluble fraction (BSF) method showed a correlation coefficient of R2= 0.88 (y(BSF)= 0.60 ×(aerosol)). Second, the aerosol data compared with total particulate matter (TPM) show a R2 of 0.83 (y(TPM)= 1.01 ×(aerosol)). Finally, total organic matter (TOM) and “aerosol + vapor” data yielded a R2 of 0.78 (y(TOM)= 0.44 ×(aerosol+vapor)). Twenty-nine pairs of roofing data were also collected; 37% were below the limit of detection. When comparing the TOM data with the aerosol + vapor data, using the 13 of 29 pairs where both samplers showed detectable results, the relationship was y(TOM)= 0.74 ×(aerosol+vapor) (R2= 0.91). The slopes within these equations provide predictive factors between these sampling and analysis methods; intended for use with large sets of data, they are not applicable to single point measurements.