welding Room The company has six welding booths, or areas that are partitioned only for the use of welding curtains. The booth is open to mixing in the front and top. The company is worried about the welder's exposure to iron oxide (PEL 10 mg/m"). For a valid sample, you must have a minimum of six hours of sampling (The remaining two hours of the work day is considered to be equal to or less than the sampled exposure. As a result of your air sampling over an eight-hour time period (i.e., the work schedule), you receive the following analytical report: Name Location Conc. 1 Time 1 Conc. 2 Time 2 Conc. 3 Time 3 Anne Welding Booth #1 4.3 mg/m 150 min. 3.7 mg/m 150 min 2.2 mg/m' 240 min 1 4308, Advanced Concepts in Environmental Safety Management