Question 1

 

1.  

 

You are an industrial hygienist conducting personal sampling on a worker who is overseeing a production process involving use of acetone (Note: The Occupational Safety and Health Administration has established a Permissible Exposure Limit of 1000 parts per million (ppm) of acetone). You are able to measure the following exposures:



700 ppm for 3 hours

1300 ppm for 2 hours

900 ppm for 3 hours



What is the calculated TWA? What would you tell plant management in terms of exposure to acetone and compliance with the PEL?

 

 

 

 

 

Question 2

 

1.  

 

Please solve the following problem, indicating your response on a Word document and submitting the document via File Upload.

 

Using the following formula, solve the problem below, and show your work.

 

TWA = CaTa + CbTb + ... + CnTn

                                8

 

TWA	=	Time-Weighted Average
Ca	=	Concentration of contaminant during the sampling period "a"
Ta	=	Time of sampling period "a"
Cb	=	Concentration of contaminant during the sampling period "b"
Tb	=	Time of sampling period "b"
Cn	=	Concentration of contaminant during the sampling period "n", where "n" is the last of a series of contaminants
Tn	=	Time of sampling period "n"

 

 

 

Note: All concentrations are in parts contaminant per million parts of air or milligrams of contaminant per cubic meter of air.



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 hour

100 ppm for 4 hours

225 ppm for 3 hours





What is the calculated TWA? What would you tell plant management in terms of exposure to toluene and compliance with the PEL?