Acetylene is manufactured commercially by reaction between calcium carbide and water. At atmospheric temperatures and pressures, it is a colorless gas. In pure form, it smells like ether, but the commercial grade has a garlic-like odor. It is also highly flammable in nature. Distinctive garlic smell Fire and explosion hazards are greater than LPG but it is slightly lighter than air and less likely to collect in ducts and drains Requires minimal energy to ignite in air or oxygen DO NOT use with copper, high copper or brass alloys because copper materials form explosive compounds with Acetylene