.. dimethyl methane, so that's .. a methane with two methyl groups replacing two hydrogen atoms. Methyl, methyl .. that's a carbon and three hydrogens (this is my brain on chemistry talking), so that's .. three carbons and .. 8 hydrogens .. wait a second...

Those bastards! They're obfuscating propane. And the CAS number in the MSDS, 74-98-6, confirms the ploy.

I wonder if a dimethyl methane refrigerant sells better than one made of propane...