On 18 July 2013 the Manufacturers of Emission Controls Association (MECA) announced the release of a new report outlining the health impacts of ultrafine particulates (UFP) from cars, trucks, and off-road equipment and the benefits of reducing both the mass and number of particulate emissions through the use of advanced emission control technology-namely, particulate filters.

The report – Ultrafine Particulate Matter and the Benefits of Reducing Particle Numbers in the United States – summarizes the current understanding of the potential adverse health impacts of UFPs; outlines the various control technologies that can be used to meet current and upcoming US EPA and California ARB emission standards; and documents the success story of using diesel particulate filters (DPF) to meet US and EU emission standards.

The report indicates that a particle number (PN) measurement may offer a more robust unit than PM mass for determining compliance at very low particle emission levels. In the report, MECA makes several recommendations for EPA and ARB to help achieve the maximum environmental and health benefits from their current and upcoming on-road and off-road emission standards:

• EPA and ARB should add a PN limit to its regulatory structure for mobile sources;
• EPA and ARB should consider a new set of heavy-duty diesel engine PM standards that would be equivalent in stringency to ARB’s future LEV III standards for light-duty vehicles;
• EPA should increase its in-use compliance monitoring of nonroad diesel engines that are certified without DPFs;
• EPA and ARB should coordinate activities to develop a methodology for measuring UFP emissions and particle numbers;
• Environmental agencies around the world should follow the U.S. lead and tighten evaporative emission limits as a way to control secondary organic aerosols; and
• Federal and state governments should play a greater role in accelerating the retirement or retrofitting of older, dirtier diesel engines and the introduction of cleaner diesel replacements.

What this means to you

Ultrafine particulate matter continues to be a primary focus of EPA and California’s ARB. This report urges both entities to work together for tighter measurements and controls of diesel engines.