CAM2 Blue Blood DEF is an American Petroleum Institute (API) certified Diesel Exhaust Fluid that meets international standards for purity and composition for use as a Nitrogen Oxide (NOx) reducing agent in all Selective Catalytic Reduction (SCR) Emission Control systems. Per specifications, it is a high purity 32.5% (by weight) aqueous urea solution (urea in de-ionized water). DEF is a reducing agent which is injected into the hot exhaust gas stream downstream of the diesel particulate filter. It vaporizes in the hot exhaust gas to form ammonia and carbon dioxide which then reacts with the SCR system catalytic converter and the NOx (oxides of nitrogen) in the exhaust, converting the harmful NOx emissions to harmless nitrogen and water. DEF meets ISO 22241-2 specifications and meets all applicable standards and specifications for use in all SCR systems.