Methane is the most basic organic molecule in existence. By definition, an organic molecule, or "hydrocarbon" is any molecule composed of carbon and hydrogen. Methane is important in reactions of organic chemicals because its small relative size and similar molecular composition allows it to react easily, serving as either the backbone of or a common addition to larger organic compounds.
Methane's tendency to react can have explosive ramifications in the real world. To this end, the Canadian Center for Occupational Health and Safety has categorized methane as a "B1 Flammable and Combustible Material" -- a flammable gas. Although this property might prove disastrous if you're in a room full of methane and need to light a cigarette, its commercial application might have more effect on your life than you know: methane is a key ingredient in the natural gas which heats homes and offices around the country.
As a result of its flammability and general reactivity, the United States Occupational Safety & Health Administration (OSHA) has classified methane as a hazardous material under section 9 CFR 1910.1200. Businesses and employers who stock methane must, according to the law, provide training to employees who will regularly come into contact with methane, post conspicuous signage near any storage area and make "Material Safety Data Sheets" (MSDS), which explain the hazardous potential for methane in detail, available to all employees and staff.