AirFlow Catalyst Systems received a letter of approval from the Pennsylvania Department of Environmental Protection for their Diesel Oxidation Catalyst (DOC). The AirFlow DOC is approved for use with a Daimler Chrysler Model OM 904LA engine on an 8 ton, seven-man personnel carrier. The approval carries to all bituminous underground coal mines in Pennsylvania. The AirFlow DOC features AirFlow’s proprietary low temperature activation to eliminate carbon monoxide and hydrocarbons from the diesel exhaust.