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Identifying and Managing Greenhouse Gas Emissions Part 1

Lorraine O'Donovan, EHSQ Alliance Affiliate

This ebook provides an introductory discussion of steps an organization or facility can take to evaluate its emissions of greenhouse gases (GHGs).



Greenhouse gas (GHG) emissions result from a wide variety of activities. As concern about climate change increases worldwide, these activities are affected by the entity’s context (whether an organization or a specific facility). Ongoing international negotiations are far beyond the day-to-day considerations of most organizations and individuals, but continue to affect national political and regulatory frameworks, and market considerations. This e-book provides the basic international and U.S. national contexts, but focuses primarily on measures that individual entities can take.

The Search for Global Agreements and National Programs

Global and national initiatives to address climate change continue to evolve, as more governments around the world embrace the scientific consensus that action is needed. Most recently, member nations of the United Nations Framework Convention on Climate Change (UNFCCC) met in Paris in December 2015 to adopt a successor to the Kyoto Protocols. Diplomats from 196 countries agreed to define national GHG reduction activities and goals, to report and review their individual and collective progress, and to cooperate in future reductions in order to keep global average temperature rise below 2 degrees C. above preindustrial levels. For example, the United States committed to reduce its GHG emissions by 26–28% below the 2005 level by 2025, and to make “best efforts” to reduce emissions by 28% -- although President Trump has instead decided to withdraw the US from the agreements. National programs reflect efforts to meet UNFCCC responsibilities, plus additional  regulatory, informational, and incentive programs. For example, in the U.S., a number of Environmental Protection Agency (EPA) programs address GHGs; most apply EPA authority under the Clean Air Act (CAA). EPA programs include:

  • Emissions limits on major sources of carbon dioxide (CO2), for facilities already subject to CAA regulation for other pollutants (“anyway” sources) (as approved by U.S. Supreme Court in June 2014). EPA is now proposing to ease these restrictions.
  • Phase-out of manufacturing and commercial distribution of many fluorinated gases (using CAA authority, supporting UNFCCC and Montreal Protocol commitments).
  • GHG emission limits from mobile sources (CAA authority; EPA had adopted limits originally adopted by California but has now proposed rollbacks for 2021-2025).
  • Mandatory GHG emissions reporting for specified sources, using separate authority.

EPA and other agencies are also responsible for limiting GHG emissions from their own activities, and for cooperating with other federal, state and local government agencies to reinforce governmental and non-governmental limitations on GHG emissions and planning for adaptation to anticipated climate change. Sub-national governments (states, provinces, cities, etc.) are establishing and coordinating their own initiatives, as are private enterprises and non-profits.

Defining Greenhouse Gases

Climate change discussions focus on gases that contribute to climate change. Most of these so-called GHGs are either fossil fuels or fluorinated gases. Many initiatives focus on a relatively small group of GHGs responsible for most contributions to climate change.

Multi-gas initiatives include the following GHGs, which were first targeted by the UNFCCC:

  • Carbon dioxide (CO2)–most emissions result from combustion of fossil fuels (oil, natural gas, coal) or renewable fuels (wood and other “biomass”).
  • Methane (CH4)–the main constituent of natural gas, which is released by incomplete combustion and leaks, and also results from a wide variety of biological processes.
  • Nitrous oxide (N2O)–another combustion byproduct, which also results from agricultural and other biological processes.
  • Hydroflurocarbons (HFCs)–used primarily for refrigeration (most have been phased-out under stratospheric ozone protection efforts under the Montreal Protocol).
  • Perflurocarbons (PFCs)–used in industrial processes, including semiconductor fabrication and aluminum manufacturing.
  • Sulfur hexafluoride (SF6)–used in the electric power industry as an insulator and arc interrupter, and more generally as a tracer.

Since 1990, additional GHGs have been identified; most are fluorinated gases. For example, in 2013 the UN-sponsored International Panel on Climate Change (IPCC) formally identified nitrogen trifluoride (NF3) and sulfuryl fluoride (SO2F2) in its Fifth Assessment Report.

In the United States, EPA programs address these core GHGs, and some apply much more broadly. For example, EPA’s mandatory GHG reporting program (discussed below) lists 179 specific GHGs (40 CFR part 98, Table A-1), including dozens of specific HFCs and PFCs, and dozens of:

  • Hydrofluoroethers (HFEs)–used as degreasers and coolants (developed as replacements for ozone depleting HFCs and other fluorocarbons).
  • Additional fluorinated gases.

In Canada, Environment Canada also administers a mandatory GHG emission reporting program, that specifies 24 GHGs. These include those listed by UNFCCC as well as a number of specific HFCs and PFCs.

Each GHG is assigned a global warming potential (GWP) number by the IPCC, based on the chemical’s relative impact on climate change (with CO2 assigned 1 as the basis for comparison). For example:

  • Carbon dioxide (CO2) - 1
  • Methane (CH4) - 28
  • Nitrous oxide (N2O) - 265
  • HFC-23 - 12,400
  • Sulfur hexafluoride (SF6) - 23,500

(EPA’s regulatory list of GHGs subject to its mandatory reporting regulation presents the latest GWPs, but has not been updated to reflect the IPCC's latest values.)

Each organization or facility should compare the chemicals it acquires, or manufactures, against applicable lists of regulated GHGs. This is the first step to determining the entity’s compliance status under applicable laws and regulations. GHGs are used for a variety of purposes, so it’s probably most efficient to start with chemical acquisition records.

Accessing Purchasing Records

First, the entity should access its purchasing records for chemicals acquired. An entity may have a single purchasing system or multiple systems. Review may require more than one step:

  • Direct purchases - a GHG purchased as a discrete item (for use in a refrigerator or industrial process, for example), volumes and even end uses can be found directly from purchasing records
  • Constituents in a direct purchase - a GHG that appears as a constituent or component in a mixture or compound; its presence must be identified from purchasing records for that mixture or compound, after which its mass or volume can be calculated
  • Produced from directly purchased chemicals - a GHG produced by mixing or joint use of constituents that are not listed as GHGs – the most obvious example is CO2 emissions from fossil fuel combustion –will not appear in purchasing records but quantities must be derived from those of the source chemicals

Further, many organizations allow bypasses around their own formal purchasing system(s) by authorizing managers to make limited purchases of materials (these are later tracked through the entity’s accounting systems but may not be linked back to chemical inventory records). Fortunately, quantities purchased by these means will probably be less than current regulatory thresholds.

Applying Chemical Information

The next step is to identify which chemicals are GHGs. The first step may include comparison of chemicals identified in purchasing records with regulatory lists of GHGs. The entity should cross-reference chemicals against applicable programs, such as:

  • EPA’s mandatory GHG reporting program (listed here) (note: GWPs are not the latest IPCC values) 
  • Environment Canada’s mandatory GHG reporting program (listed here)

For mixtures and chemicals produced onsite, entities can access information developed to comply with requirements that employers evaluate the hazards posed by the chemicals their employees manufacture and use. In the U.S. the primary regulation is the Hazard Communication Standard (HCS) administered by the federal Occupational Safety and Health Administration (OSHA) and delegated state agencies, and in Canada the primary regulation is the Workplace Hazardous Materials Information System (WHMIS) requirement imposed by Health Canada and provincial agencies. HCS and WHMIS require employers to obtain Safety Data Sheets (SDSs) for “hazardous chemicals” in their workplaces (replacing longstanding Material Safety Data Sheets (MSDSs)). Each SDS and MSDS identifies each constituent in a chemical product present in concentrations higher than one percent (0.1 % for carcinogens). SDSs/MSDSs also identify at least some regulatory programs applicable to the chemical, but these may or may not identify requirements on GHGs.

Additional environmental, health and safety (EH&S) programs also require targeted entities to prepare inventories of specific hazardous chemicals. These include:

  • EPA’s Emergency Planning and Community Right-to-Know Act (EPCRA) inventory requirements, for chemicals present at or above threshold quantities (10,000 pounds for chemicals requiring a SDS/MSDS, or lower threshold planning quantities for specified extremely hazardous substances; some analogous state programs set lower thresholds).
  • Fire code required Hazardous Materials Management Plan, based on International Fire Code with reporting thresholds and other details set by state and local agencies.


The following section discusses ways GHGs are used, to help readers identify sources of GHG emissions, and to prepare to calculate (or at least estimate) these emissions. Entities should prepare an “emissions inventory” for each facility or organizational unit, which then can be analyzed and managed independently, and/or aggregated to larger product and supply chains, or by organizational units or geographic areas.

Combustion of Fuels (Fossil and Renewable)

Many entities operate mobile and/or fixed units that burn fossil fuels or biomass. All these sources emit CO2 and probably other GHGs (notably N2O) during their
operation, and some leak volatiles between uses. Look for the following types of source categories:

  • Stationary combustion: in stationary equipment such as boilers, furnaces, burners, turbines, heaters, incinerators, engines, etc.
  • Mobile combustion: in automobiles, forklifts, trucks, buses, trains, airplanes, boats, ships, barges, vessels, etc.
  • Process emissions: from physical or chemical thermal processes, such as CO2 from calcination in cement manufacturing or from catalytic cracking in petrochemical processing, PFC emissions from aluminum smelting, etc.
  • Fugitive emissions: intentional and unintentional releases including equipment leaks from joints, seals, packing, gaskets, and off-gases from coal piles, wastewater treatment, pits, cooling towers, gas processing facilities, etc.

Note that many GHG reporting programs treat fossil and renewable/biomass emissions differently. Fossil fuel combustion returns long-sequestered carbon to the environment, while renewables combust carbon that has been more recently incorporated into wood or other biological materials so its release is often considered to make no long term contribution to climate change.

Use of Fluorinated Gases

Fluorinated gases–particularly CFCs and HCFCs –have been the primary targets of stratospheric ozone protection efforts since the 1980s, under the international framework under the Montreal Protocol on Substances that Deplete the Ozone Layer (agreed to in 1987, entered force on January 1, 1989). The Montreal Protocol and signatory nations’ requirements assign a numerical “ozone depletion potential” that represents each substance’s relative potential to contribute to ozone depletion, and define Class I substances (highest ozone depleting potential) and Class II substances (next highest). Class I includes CFCs and methyl bromide, which were subject to phase-out deadlines for production and use during 1996 – 2005 (“essential uses” exceptions are available). Class II includes HCFCs, with phase-out deadlines during 2003 – 2030 (essential use exceptions are available). As climate change issues have become more important in recent years, climate scientists have determined that many ozone depleting substances are also GHGs. The 2016 Kigali Amendment to the Montreal Protocol is designed to reduce emissions of HFCs that are subject to the Montreal Protocol and also are GHGs.

An entity that still uses Class I or II ozone depleting substances should only be doing so in compliance with applicable standards. SF6 has been in use for many years but most other fluorinated gases have been introduced since the 1980s as less-depleting alternatives to CFCs and HCFCs. Entities that manufacture or use fluorinated gases need to expand their material tracking to include these additional GHGs.

Fluorinated gases are typically used for the following:

  • Refrigerants (remaining CFCs, and gases developed as substitutes)
  • Solvents and de-greasers
  • Industrial process components (e.g., in electronics and aluminum)
  • Foam blowing agents
  • Fire suppression systems
  • Tracers

EPA applies CAA authority to certify professionals who repair and maintain refrigeration equipment, and to require that owners and operators of such equipment ensure that it is maintained, serviced, and repaired only by certified personnel. Documentation developed to comply with these requirements can also inform evaluation of GHG use and emission.




The professional experience of Jon F. Elliott, BSE, MPP, JD, includes:

  • Practicing attorney in California.
  • Compliance consultant and legal advisor (since 1985), specializing in projects that address multiple legal frameworks simultaneously.

Jon Elliott has made a major contribution to the Specialty Technical Publishers (STP) product range for over 30 years. Examples include:

Mr. Elliott has a diverse educational background. In addition to his Juris Doctor (University of California, Berkeley Boalt Hall School of Law–1981), he holds a Master of Public Policy (Goldman School of Public Policy, UC Berkeley–1980) and a Bachelor of Science in Mechanical Engineering (Princeton University–1977).

Lorraine O’Donovan is a Marketing Specialist for Specialty Technical Publishers.


In the second part of this eBook, the author will discuss Calculating and Considering GHG Emissions. 

[Editors' Note: Republished with permission. This is the first part of a two-part eBook from STP. (Copyright © 2018 Specialty Technical Publishers. All Rights Reserved.) This publication does not constitute legal, accounting or other professional advice. STP Specialty Technical Publishers and its authors make no warranties, whether express or implied, regarding the accuracy of any information or materials contained herein or the results of any course of action described herein, and STP and its authors expressly and specifically disclaim the implied warranties of merchantability and fitness for a particular purpose.]



This material provided by the Intelex Community and EHSQ Alliance is for informational purposes only. The material may include notification of regulatory activity, regulatory explanation and interpretation, policies and procedures, and best practices and guidelines that are intended to educate and inform you with regard to EHSQ topics of general interest. Opinions are those of the authors, and do not necessarily reflect the opinion of Intelex. The material is intended solely as guidance and you are responsible for any determination of whether the material meets your needs. Furthermore, you are responsible for complying with all relevant and applicable regulations. We are not responsible for any damage or loss, direct or indirect, arising out of or resulting from your selection or use of the materials.   

September 06, 2018 @ 09:14 AM EDT Manufacturing, Chemical, Energy - Electricity Environment

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Katie Bell's picture
Katie Bell

An emission just alludes to the way that it was radiated. There is no implication related with the term. Ozone depleting substances are not terrible. There would be substantially less life on Earth without them. According to the research of Top Coursework Writing Service UK Water vapor is the principle ozone depleting substance, however inner burning motors and individuals who inhale radiate carbon dioxide also.

September 13, 2018 @ 07:42 AM EDT