Sulphur Emission Control Area traces of heavy metals, refined petroleum products containing halogen compounds, sewage sludge and sludge oil. The Marine Environment Protection Committee (MEPC) has strongly encouraged members to use the scheme to report the greenhouse gasses emissions. Those gasses include Carbon dioxide, Methane, Nitrous oxide, Hydrofluorocarbons, Perfluocarbons, and Sulfur hexafluoride. The purpose of making the guidelines on CO2 emissions is to develop a system that would be used by ships during a trial period. In 2013 new regulations described in a chapter added to the MARPOL Annex VI came into effect in order to improve "energy efficiency of international shipping. The regulations
Volcanic gas gases), nitrogen, argon, helium, neon, methane, carbon monoxide and hydrogen. Other compounds detected in volcanic gases are oxygen (meteoric), hydrogen chloride, hydrogen fluoride, hydrogen bromide, nitrogen oxide (NO), sulfur hexafluoride, carbonyl sulfide, and organic compounds. Exotic trace compounds include mercury, halocarbons (including CFCs), and halogen oxide radicals. The abundance of gases varies considerably from volcano to volcano, with volcanic activity and with tectonic setting. Water vapour is consistently the most abundant volcanic gas, normally comprising more than 60% of total emissions. Carbon dioxide typically accounts for 10 to 40% of emissions. Volcanoes located at convergent plate boundaries emit more water