gas/vapor hazard, is the substance a chemical or biological hazard and how?

gas/vapor hazard,

is the substance a chemical or biological hazard  and how?

Name chemical properties (vapor pressure, vapor density, molecular weight, relative size) and how these properties affect the different routes of exposure.

which exposure route is the most important?

how the substance could enter the body through the dermal route, and discuss why the dermal route would or

would not be important.