Hello All,

Thought I would share this site with the readers here. Jane, you are quite right about the smell and weight of the vapors. Both methane and propane are in a homologous group of organics called alkanes. Methane is CH4, whereas propane has 3 carbons and 8 hydrogens, C3H8, so it has a greater molecular weight.

Just a couple other things to know;

Mercaptan draws house flys. Good way to detect a leak. Also a single cubic foot of propane has the potential to create 50,000 cubic feet of ignitable vapor. Ofcourse, the worst nighmare for fire fighters is a large tank of propane that is rapidly expelling the gas, and NOT on fire. This creates a large volumetric cloud of flammable atmosphere. At this point the pressure temperature relationship within the tank is comprimised, and the liquid propane begins to boil. It's all over. The vapors will escape faster and faster, at which time the breach is super heated via friction. The result is auto-ignition and a huge, powerful fire ball. A massive bomb. Air burst. BLEVE> Belated expansive vapor explosion. You never know, this bit of knowledge may save your life.

glen - Ex CDF Engineer

• Mercaptan