California Environmental Quality Act Office of Planning and Research to develop and recommend new guidelines to analyze greenhouse gas impacts under CEQA. California’s Natural Resources Agency adopted new guidelines on December 31, 2009, requiring lead agencies to analyze greenhouse gas emissions under section 15064.4 during their CEQA review through California. The major category of greenhouse gas emissions resulting from human activities is carbon dioxide. Several other primary gases also include methane, nitrous oxide, sulfur hexafluoride, perfluorocarbons, and hydrofluorocarbons. Greenhouse gas sources resulting from project construction activities are typically generated from transportation of materials to the project site and petrol based equipment used during construction
Nitrous oxide aid responders in prehospital settings, given the relative ease and safety of administering 50% nitrous oxide as an analgesic. The rapid reversibility of its effect would also prevent it from precluding diagnosis. Recreational inhalation of nitrous oxide, with the purpose of causing euphoria and/or slight hallucinations, began as a phenomenon for the British upper class in 1799, known as "laughing gas parties". Starting in the nineteenth century, widespread availability of the gas for medical and culinary purposes allowed the recreational use to expand greatly, throughout the world. In the United Kingdom, as of 2014, nitrous oxide was estimated to be