The largest source of air emissions at our sites is carbon dioxide (CO2) from the production and use of energy and from other combustion processes, such as thermal oxidizers (for treating air emissions) and solid-waste incinerators. For more information on our greenhouse gas emissions and energy use, click here.
The combustion processes that produce our energy also result in emissions of nitrogen oxides (NOx) and sometimes sulfur oxides (SOx), depending on the fuels used. As we reduce the need for energy production through our efficiency projects, we will also be reducing the emissions of NOx and, in some cases, the emissions of SOx. We have expanded the scope of our NOx and SOx reporting to incorporate emissions from leased facilities and fleet-vehicle emissions. Reductions in the number of fleet vehicles have resulted in overall decreases in SOx, while NOx has remained relatively constant.
The largest source of air emissions directly from our manufacturing processes is solvent use, which is the primary component of both volatile organic compounds (VOCs) and Toxic Release Inventory (TRI) compound emissions to air. Two of our new goals target reducing these pollutants. Our Green Chemistry and VOC reduction goals will lead to lower levels of toxic emissions in general and lower VOC emissions specifically. VOC emissions decreased over 15 percent from the 2009 baseline year, in large part as a result of certain processes being discontinued and improved emission-tracking methods.
Our current emissions of ozone-depleting compounds, which are primarily due to minor leaks from temperature-control systems, are small compared with other emissions from our sites and remain relatively constant. Nevertheless, we will continue to monitor them for improvement opportunities.