Pure methane is a colourless and odourless gas (odorant may be added by supplier). It is an EXTREMELY FLAMMABLE GAS, and is a COMPRESSED GAS or REFRIGERATED LIQUEFIED GAS. Methane may cause a flash fire. It is essentially non-toxic at low concentrations. At high concentrations, methane can reduce oxygen available for breathing causing asphyxiation. Methane is a confined space hazard because it can accumulate in confined spaces, producing a fire and asphyxiation hazard. Direct contact with methane as refrigerated liquefied gas or compressed gas escaping from its cylinder can cause cold burns or frostbite.

Methane is the major constituent of natural gas, which is a heating fuel widely used by residential and commercial markets. It is also used to make synthesis gas, which is a mixture of hydrogen and carbon monoxide gases. The synthesis gas is then used in the production of methanol, acetic acid and acetic anhydride, ammonia, halogenated methanes, and for chemical vapour deposition of carbide and diamond films.

Methane naturally occurs in underground gas reservoirs, oil wells, coal mines, marshland, agricultural sites, sewage sludge, and landfills.

Technical and higher grades of methane are at least 98% pure and are not odourized. These grades contain trace impurities such as nitrogen, hydrogen, oxygen, water, carbon monoxide, carbon dioxide, ethane, propane and propylene.

Methane is also known as methane, compressed gas; methane, refrigerated liquid; methyl hydride; marsh gas; fire damp.

Its CAS Registry Number is 74-82-8. This number is assigned by the Chemical Abstracts Service (CAS) in the United States and is used as a unique identifier number world-wide.