You are asked to evaluate employees’ exposures to methyl n-amyl ketone during a painting operation. After careful consideration, you choose NIOSH Method 2553 for the sampling. Unit IV Discussion Board Question Discuss a gas or vapor that you have dealt with in a workplace. Include information about how worker exposures were evaluated. If you have never had sampling for a gas or vapor performed in your workplace, review either the NIOSH Manual of Analytical Methods (NMAM) or the OSHA Sampling and Analytical Methods, and choose a vapor or gas that looks interesting to you.