ïSkin contact with liquefied Methane can cause frostbite. ï Very high levels of Methane can decrease the amount of. Oxygen in the air and cause suffocation with symptoms of. headache, dizziness, weakness, nausea, vomiting, loss of. coordination and judgment, increased breathing rate and. loss of consciousness. ï Methane is a FLAMMABLE GAS and a DANGEROUS FIRE.