This CTS Knowledge Base article provides general guidelines for handling and disposal of ash removed from DPFs, as well as disposal of DPFs and DOCs at the end of their useful life. Handling of ash and disposal of aftertreatment systems should follow all federal, state, and local guidelines.
Classification and Handling of Diesel Particulate Filter (DPF) Ash
Ash contains a complex mixture of engine lubricant additives, wear metals, and many other non-combustible materials that have made their way through the engine and exhaust system. In many cases, ash, once freed from the DPF, exists as a loose powder. Care must be exercised when overseeing loose ash powders; handling and disposal measures must follow all local, state, and federal guidelines.
Sources of ash were described in detail in an article discussing ash composition and include lubricant additives, trace metals in fuels, engine wear, corrosion products, and in some cases, ambient or environmental sources.
According to the Air Resources Board (ARB) in the State of California, ash is likely to be classified as a hazardous waste. This is due primarily to the high levels of zinc which may exist in the ash from zinc-based additives in the engine oil. As such, care should be exercised when handling DPFs that contain ash or loose ash removed from the DPF. It is illegal to dispose of hazardous waste by placing it in ordinary trash, introducing it into the air or ground, or washing it into the sewer system in the State of California .
Given the small size of the ash particles, ash removed from the DPF should be contained in a sealed container for proper disposal. Care should be taken to avoid dispersing the ash into the air. Protective masks, safety goggles, and gloves are recommended for handling or working around ash removed from diesel particulate filters.
DPFs and Diesel Oxidation Catalysts (DOCs) which have reached the end of their useful life should be recycled or reclaimed following the same practices used for handling ash, as the parts themselves still contain accumulated ash.
Why is this important for DPF ash cleaning?
Precautionary measures should be employed when handling ash removed from DPFs, as well as parts containing ash. Disposal of ash and emission control components containing ash should follow all federal, state, and local guidelines. Contact the manufacturer of your emission control system for additional details regarding system-specific handling, maintenance, and disposal practices.
- California Environmental Protection Agency, Air Resources Board. http://www.arb.ca.gov/diesel/tru/documents/ashguide.pdf