Gas that occurs in coal mines and is explosive when mixed with air in certain proportions. It consists chiefly of methane (CH4, natural gas or marsh gas) but always contains small quantities of other gases, such as nitrogen, carbon dioxide, and hydrogen, and sometimes ethane and carbon monoxide.
The quetzal, the national bird of Guatemala, symbolizes freedom. The blue bands stand for the Caribbean Sea and the Pacific Ocean. The weapons represent the defence of liberty. Effective date: 15 September 1968.