# Regulation (EC) No 2003/2003 of the European Parliament and of the Council of 13 October 2003 relating to fertilisers (Text with EEA relevance), Article 17: Declaration of secondary nutrients in primary nutrient fertilisers

Extent: E+W+S+N.I.

Calcium, magnesium, sodium and sulphur content may be declared as secondary nutrient content of UK fertilisers belonging to the types of fertiliser listed in sections A, B and C of Annex I, provided that these elements are present in at least the following minimum quantities:
(a)2 % calcium oxide (CaO), i.e. 1,4 % Ca;
(b)2 % of magnesium oxide (MgO), i.e. 1,2 % Mg;
(c)3 % of sodium oxide (Na2O), i.e. 2,2 % Na;
(d)5 % of sulphur trioxide (SO3), i.e. 2 % S.
In such a case, the additional marking specified in Article 19(2)(ii) shall be added to the type designation.

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Source: https://www.legislation.gov.uk/eur/2003/2003/article/17 (the official version)
Page: https://openlegislation.uk/eu-regulation-2003-2003/article-17
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.