Full explanation
AdBlue (VDA trademark; in the US known as DEF — diesel exhaust fluid) is mandatory on all Stage V and Tier 4 Final tractors. Quality is critical — technical-grade urea without ISO 22241 crystallizes in the SCR dosing unit and destroys the catalyst (rebuild USD 4,000–12,000). Main Ukrainian producers: OKKO, WOG, BRSM-Nafta, Navoil. Storage between −11°C (freezing point) and +30°C in UV-opaque containers (UV degrades urea). Plastic and stainless steel OK; carbon steel and copper strictly no (corrosion). Below −11°C, tractor in-tank heating is used. SCR-emulators (which bypass the AdBlue system) are illegal under EU Reg 2016/1628 — UAH 40–170k fines under Ukraine's Administrative Offences Code. Counterfeit AdBlue is estimated at 15–25% of Ukraine's small-pack retail market.