Adding oxygen to the urea process has proven to be an effective and reliable way to minimize corrosion to the stainless steels used in plants. However since the introduction of this technology in the early 1950s, the fire and explosion risk associated with oxygen (air) in urea synthesis has required special attention in design and operation. Experience and knowledge on safer operating procedures has grown over the years, through experience gained in operating plants, as well as through fundamental research. At the same time, the chemical process industry has needed to comply with stricter safety regulations. Let there be no doubt, Stamicarbon thinks these increased demands on safety related topics certainly are justified. The combination of growing insight on the one hand, and increasing demands on the other hand, justifies a regular update of safety guidelines and standards.