Basic Indicators Characteristics for Grade B 1. Mass friction of nitrogen in terms of dry matter 46.2 2. Mass friction biuret, %, not more than 0.6 3. Mass friction of ammonia, %, not more than, for urea: Crystal 0.01 In Granules 0.02 4. Mass friction of water, %, not more than: hygroscopic 0.3 general 0.6 drying method 0.3 Fisher's method 0.5 5. Friability,% 100