Survey report: control technology evaluation for controlling worker exposure to asphalt fumes from roofing kettles: kettle operated using low fuming asphalt at Raytheon Corporation, Fort Wayne, Indiana, report no. CT-231-12b.
A survey was conducted September 18-21, 2000, at the Raytheon Corporation building in Fort Wayne, Indiana where a 2-ply built-up roof with mineral surface fiber glass cap sheet was being applied on top of the existing roof. No tear-off of the old roof was performed. The engineering control used during this evaluation was low fuming asphalt. Other existing engineering controls for this industry will be evaluated in subsequent surveys. A final report will summarize the engineering controls evaluated from all of the surveys. In order to develop useful and practical recommendations, the ability of the engineering control measure to reduce worker exposure to air contaminants must be documented and evaluated. For this study, where practical, this was accomplished by evaluating workers' exposure to asphalt fume particulate and PACs both with and without low fuming asphalt. Personal breathing zone and area air samples were collected and analyzed for total particulate (TP), benzene soluble fraction (BSF) of the total particulate I using NIOSH Manual of Analytical Methods (NMAM) Method 5042, and PACs using NMAM Method 5800.36 The temperature of the hot asphalt was recorded periodically with an electronic thermocouple and compared to the temperature gauge permanently mounted on the kettle. Only TruLo low fuming roofing asphalt was used during this survey; therefore, comparisons between conventional and low fuming asphalt exposure results were not possible. Comparing these results to data collected at a previously surveyed roofing site, the Toledo Correctional Institute, where low fuming asphalt was also used, the results were very similar. The kettle operator (GP-0l) at the Toledo roofing site had mean NTP TP, BSF, and total PAC concentrations of 1.30mg/m3, 0.21mg/m3, and 61microg/m3, respectively. The kettle operator (1F-01) for this site had mean NTP TP, BSF, and total PAC concentrations of 0.54mg/m3, 0.34mg/m3, 66microg/m3, respectively. Aside from the mean NTP TP results, the results for the two kettle operators were very similar. The area air sample results for the samples collected around the kettle at the Toledo site when low fuming asphalt was used for mean NTP TP, BSF, and total PAC were 0.43mg/m3, 0.37mg/m3, and 42microg/m3, respectively. The area sample results for the samples collected around the kettle at this site for mean NTP TP, BSF, and total PAC were 0.30mg/m3, 0.22mg/m3, and 34microg/m3, respectively. Comparing samples collected around the kettle from the two sites showed very similar results for mean NTP TP, BSF, and total PAC. The mean NTP TP, BSF, and total PAC concentration results for the roof level workers at the Toledo site when low fuming asphalt was used were 0.38mg/m3, 0.23mg/m3, and 51microg/m3, respectively. The mean NTP TP, BSF, and total PAC concentration results for the roof level workers at this site were 0.72mg/m3, 0.54mg/m3, and 98microg/m3, respectively. The results for the roof level workers at this site were all higher in concentration than those from the Toledo site. During this survey, samples were collected for four days during which low fuming asphalt was used. Although it was not possible to compare these results with those for conventional asphalt at this site, the sample results indicate that the exposures when low fuming asphalt was used are very similar to those measured at a previously surveyed roofing site where low fuming asphalt was used.