National Clean Diesel Campaign
                     Emissions from Platinum Based Fuel Additives
The National Clean Diesel Campaign strives to provide reliable information to users of retrofit
technologies and the public about the emissions reductions that can be expected from specific
diesel retrofit technologies. EPA has received questions about the possible health effects of
exposure to platinum and cerium from diesel retrofit technologies that use platinum/cerium-
based fuel additives.  In response, EPA is carefully studying the issue to evaluate potential risks.

The use of a platinum/cerium-based fuel additive produces emissions of platinum and cerium in
the exhaust.  EPA is currently reviewing health information regarding exposure to cerium
compounds and specific chemical forms of platinum. Some chemical forms of platinum
emissions may pose greater health concerns than others. Occupational health studies have linked
exposure to soluble forms of platinum (particularly the halogenated platinum  salts) with allergic
sensitization and respiratory effects including allergic asthma if the exposure continues.

Actual emissions of platinum and cerium depend on several factors, including the rate at which
the additive is used and the circumstances under which vehicles using the additive are operating
(e.g., if the vehicle's engine is starting and cold, idling,  or operating under heavy load).  EPA is
evaluating available emissions data and health effects studies in an effort to assess potential
health risks associated with platinum- or cerium-based fuel additives and will notify the public of
any additional actions the Agency may take.