You are asked to evaluate employees' exposures to methyl n-amyl ketone during a painting operation using NIOSH Method 2553 for the sampling. You can access the method by clicking the link below:

 

National Institute for Occupational Safety and Health. (2003). Ketones II: Method 2553. In P. M. Eiler & M. E. Cassinelli (Eds.), NIOSH manual of analytical methods (4th ed.). Centers for Disease Control and Prevention. http://www.cdc.gov/niosh/docs/2003-154/pdfs/2553.pdf

 

Please answer the following questions:

1. Your pre-sampling and post-sampling pump calibration using a primary standard are both 0.05 L/min. You collect a personal sample on an employee working in the operation. The sample is collected for 460 minutes. Calculate the sample volume.
2. The laboratory reports that the front section of the sample contains 4,500 µg of methyl n-amyl ketone and the back section contains 100 µg of methyl n-amyl ketone. Neither the front nor back sections of the field blank you supplied contain any detectable levels of methyl n-amyl ketone. Calculate the concentration of the sample in µg/L and mg/m³. Convert the result to ppm (MW for methyl n-amyl ketone = 114.2). Note: Use the ideal gas constant of 24.45.
3. You then reference OSHA's Table Z-1 and find that the 8-hour TWA PEL for methyl n-amyl ketone is 100 ppm. You also look up the ACGIH TLV for methyl n-amyl ketone and find that the TLV is 50 ppm as an 8-hour TWA exposure. Discuss how the results of the two personal samples you collected compare to the OSHA PEL and the ACGIH TLV.
4. Discuss whether you would recommend comparing the results of your sampling to the OSHA PEL or the ACGIH TLV. Include your rationale for the choice.