S-1

A 2-lb cylinder of chlorine gas fell off a lab table and broke, permitting the gas to escape into a closed room of 50 by 27 by 15 ft.

1. Calculate the concentration in parts per million. The barometric pressure is 760 mm Hg, and the temperature is 22 C.

2. On the basis of the current TLVs (threshold limit values), would it be dangerous to remain in this room for 3 hr?

S-2

1. Calculate a worker's daily 8-hr exposure to a solvent with a current threshold limit value (TLV) of 100 ppm if the worker spends 1 hr at an operation where the concentration is 250 ppm, 4 hr at 200 ppm, and 3 hr at 100 ppm.

2. If you returned to this same plant two weeks later and found similar exposures at the same operation, would you recommend that control measures be instituted? If so, why?

S-3

The acoustical treatment of a room has reduced the over-all noise level by 3 dB. By what factor has the acoustical power been reduced?

S-4

Estimate the sound pressure level at 10 ft for the following vents:

• Vent No. 1

  • Saturated steam

  • Valve size 4 in.

  • Temperature 400 F

  • Pressure 250 psig

  • Molecular weight 18

• Vent No. 2

  • Saturated steam

  • Valve size 6 in.

  • Temperature 200 F

  • Pressure 200 psig

  • Molecular weight 18

• Vent No. 3

  • Air

  • Valve size 2 in.

  • Temperature 75 F

  • Pressure 250 psig

  • Molecular weight 29

Vent noise correction factor for saturated steam = ?5.0, for air =...