The Diesel Exhaust Fluid (DEF) shall be AUS 32 (Aqueous Urea Solution 32.5%) designed specifically for use in “Selective Catalytic Reduction” (SCR) systems to reduce emissions of oxides of nitrogen (NOx) from diesel engine transit buses. 2.1.1 The DEF shall meet the requirements as outlined in the specifications section of Cummins Service Bulletin No. 4021566, latest revision. The urea content of the DEF solution shall be 32.5 percent ± 0.7 percent by weight. The DEF shall meet the International Organization for Standardization ISO 22241-1 (latest revision, for diesel engines) and be certified by the American Petroleum Institute (API). 2.1.2 The product shall be safe to manage, non-explosive, non-flammable, non-toxic, non-polluting, stable, colorless, biodegradable, and composed of urea and water. 2.1.3 Documentation or labeling shall be provided indicating when the DEF was manufactured. The DEF shall have a minimum shelf life of twelve (12) months from the time of delivery. PRT’s storage tanks are located indoors at each location. 2.1.4 The DEF shall be compatible with Cummins Selective Catalytic Reduction (SCR) systems. ` 2.1.5 Agricultural grade urea mixes shall not be acceptable in this contract and are not approved for use with Cummins on-highway emission systems.
