Question

Calculate the Vapor Hazard Ratios for methanol and methyl styrene. Based on your results, compare the potential health hazard of spilling a liter of methanol to spilling a liter of methyl styrene in a closed room.

Answer 1

Vapor Hazard Ratio can be calculated from the following formulae

Vapor Hazard Ratio = Immediately dangerous to life or health(IDHL) concentration / Occupational exposure limit(OEL)

or Vapor Hazard Ratio = IDHL / OEL

For methanol: IDHL = 25000 ppm

OEL = 200 ppm

=>  Vapor Hazard Ratio = IDHL / OEL =  25000 ppm / 200 ppm = 125

For methyl styrene: IDHL = 5000 ppm

OEL = 10 ppm

=>  Vapor Hazard Ratio = IDHL / OEL = 5000 ppm / 10 ppm = 500

Since the vapor hazard ratio f methanol is higher, methanol is more hazardous.