Compostable

According to EN 13432, a material to be defined as “compostable” must have the following characteristics:

In contact with organic materials for a period of 3 months, the mass of the material shall consist at least 90 % of fragments smaller than 2 mm; these values shall be tested by the standard method EN 14045;

the material must not adversely affect the composting process;
low concentration of heavy metals added to the material;
pH values within the established limits;

salt content within the set limits;
concentration of volatile solids within the limits laid down;
concentration of nitrogen, phosphorus, magnesium and potassium within the limits.