![]() The welders monitored were using flux-cored arc welding (FCAW) while building railroad locomotives. A total of 40 sets of four samples on each welder at each of these locations were collected. Goller and Paik (1985) described the results of simultaneously air sampling with collection sites at four locations – the welder’s body, the left front shoulder, the right front shoulder, the front chest, and inside the helmet. Breathing zone sampling location during welding fume exposure assessments has been a subject of discussion for several years. OSHA ID-215 does not address the sample location or position other than the cassette should be in a vertical position with the inlet facing down. Therefore, it is now routine analytical procedure for the lab analyst to the wipe interior walls of sampling cassettes for all metal samples. ![]() Tests showed that Cr(VI) equivalent to 0 to 123% of the amounts found on the PVC filter were present on the interior walls of cassettes. Significant amounts of Cr(VI) are often deposited on the interior walls of the sampling cassettes. Studies indicate that the loss exceeded 10% after seven days. ![]() Storage stability tests showed that these samples were not stable for longer periods of time. However, Cr(VI) samples collected from welding operations must be analyzed within eight days of sampling in accordance with OSHA ID-215 to minimize the effects caused by the interaction of Fe(II) and Cr(VI) to form Cr(III). NIOSH Analytical Method 7605 is comparable to OSHA Method ID-215.Ĭr(VI) samples collected on PVC from welding operations do not require field stabilization as with Cr(VI) samples collected from other operations (such as samples collected during chromium plating operations). The recommended flow rate is 2.0 liters per minute for 480 minutes (i.e., 960 liters). This method involves collecting an air sample onto a 5.0 micron polyvinyl chloride (PVC) membrane mounted in a 37-mm or 25-mm polystyrene cassette holder. OSHA specifically references exposure monitoring to be performed using OSHA Method ID-215 (or equivalent). Sampling and Analytical MethodsĮxposure monitoring should be performed using a sampling method that is at least ☒5% accurate. This paper describes sampling and analytical methods for Cr(VI) and considerations when conducting exposure monitoring for Cr(VI). Additionally, exposure monitoring must be performed whenever there is a change in work processes or materials that may result in new or additional exposures to Cr(VI). For exposures that are determined to be at or above OSHA’s Action Level of 2.5 μg/m3 (8-hour TWA), exposure monitoring must be performed every six months. For exposures that are determined to be at or above OSHA’s PEL of 5 micrograms per cubic meter (μg/m3) (8-hour TWA), exposure monitoring must be performed at least every three months. If the scheduled monitoring option is used, exposure monitoring must be performed initially and periodically. If objective data is used, the data must reflect workplace conditions closely resembling the processes, types of material, control methods, work practices, and environmental conditions. Options for exposure determinations include initial and periodic exposure monitoring and/or the use of objective data. ![]() ![]() OSHA requires employers to determine Cr(VI) exposures to employees. ![]()
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