Question; Air Sampling Problem: You are an industrial hygienist that is conducting personal sampling

Question; Air Sampling Problem: You are an industrial hygienist that is conducting personal sampling on a worker who is overseeing a production process involving use of toluene (Note: The Occupational Safety and Health Administration has established a Permissible Exposure Limit of 200 parts per million (ppm)). You are able to measure the following exposures:500 ppm for 1 hour100 ppm for 4 hours225 ppm for 3 hoursWhat is the calculated TWA? What would you tell plant management in terms of exposure to toluene and compliance with the PEL?