Editing MAPP gas (section)

==Physical properties==
MAPP is colorless in both liquid and gas form.  The gas has a pronounced acetylene-like or fishy odor at concentrations above 100 [[parts per million|ppm]], due to the addition of substituted amines as a polymerization inhibitor. Low molecular weight alkynes have strong odors. MAPP gas is [[toxic]] if inhaled at high concentrations.

The composition of the supplied gas has varied widely, with the gases as supplied by different repackagers/resellers at any one time varying, as well as the general composition varying over time, but a typical composition for an early Dow gas might be: [[methylacetylene]] (propyne) 48%, [[propadiene]] 23%, [[propane]] 27%. For a later Dow/Petromont gas propyne 30%, propadiene 14%, propylene 43%, propane 7%, C<sub>4</sub>H<sub>10</sub> ([[isobutane]], [[butane]]) 6% might be more typical.