EVS-EN 13266:2002

This European Standard specifies a method of the determination of the slow release properties of nutrients from coated fertilizers. pH-dependent hydrolysis and degradation by biological or microbial mechanisms are excluded.
The specified method is only applicable to products releasing any nutrients by means of a non-biological process (i.e. those where the nutrientsare released by a  physical mechanism). Microbial attack on the coating (e.g. sulfur coated fertilizers) and the consequences thereof are not measurable by the technique described.