Diesel Exhaust Fluid (DEF) comprises a high-purity urea and de-ionized water solution, serving as the essential operating fluid for vehicles employing Selective Catalytic Reduction (SCR) technology. Engineers designed this technology to adhere to the stringent b2010 emission standards, aimed at reducing nitrogen oxide (NOx) exhaust emissions from diesel engines. The fluid is stored in a designated DEF tank and is injected into the exhaust system before the catalytic converter facilitates the conversion of NOx into harmless nitrogen and water vapor.