1. In a semiconductor manufacturing operation, isopropyl alcohol is used to clean parts. There are 100 workstations and each one uses 1 pint of isopropyl alcohol per day. What level of dilution ventilation is needed to keep the air concentrations below the PEL of 400 ppm? (MW =60.1 g/mole; density = 0.79 g/cc; K = 3)

2. Calculate pounds per minute

3. Plug in the formula

4. Time-weighted average Find the time-weighted average for the following: Time8 – 10:3010:30 – 12:00 12 – 3:153:15 – 4:00 Conc100 ppm125 ppm75 ppm50 ppm PEL for toluene is 376 mg / M3; is TWA above PEL? (MW = 92 g / mole)

5. TWA Solution

6. Decible Addition Sum decibel readings of 85 dBA, 87 dBA, 87 dBA, 90 dBA For the sum, what is the exposure time allowed under the OSHA PEL?

7. Decibel solution

8. Final Problem Set Here is the final problem set. It looks like the one I uploaded earlier did not print out correctly. Use this one – there are only 3 problems. I will put up some more, if I have time.