SIST EN 13535:2002

SIST EN 13535:2002 is the Slovenian adoption of EN 13535:2001, published by SIST for the fertilizers sector. It specifies a classification system for fertilizers and liming materials, so manufacturers, laboratories, regulators and buyers can place products in the correct group and use the same product names. The standard explains the meaning of each heading and notes that some products may be classified differently in some countries.

What does SIST EN 13535:2002 specify?

SIST EN 13535:2002 specifies a classification scheme for fertilizers and liming materials. It is organized as a short front matter, Clause 1 on scope, Clause 2 on normative references, Clause 3 on terms and definitions, Clause 4 on classification, and Figure 1 showing the classification scheme.

The practical purpose is to give one common product structure for the sector while allowing for national differences in nutrient-content limits and, in some cases, classification practice. That matters when a product has to be named, compared, or placed into a regulatory category in more than one country.

What are the key requirements of SIST EN 13535:2002?

SIST EN 13535:2002 classifies products mainly by origin and by the nutrients they can declare. The classification is built around whether a product is inorganic, organic, or of mixed origin, and whether it contains declarable nitrogen, phosphorus or potassium.

1. The classification is based on clear product families

Clause 4 divides products into inorganic fertilizers and liming materials, organic fertilizers, and fertilizers of mixed origin. In practice, this is the first decision point: a product is not classified only by what it contains, but also by how it functions and where its nutrients come from.

2. Inorganic fertilizers are split by declared nutrients

Clause 4.1.1 distinguishes straight fertilizers with one declarable main nutrient from compound fertilizers with two or three. The scheme covers straight N, P and K fertilizers, and compound NP, NK, PK and NPK fertilizers.

For users, this means the product name must match the nutrient profile. A product with declared nitrogen only is treated differently from one with declared nitrogen and phosphorus, even if other elements are present.

3. Inorganic fertilizers also include other nutrient groups

Clause 4.1.1.2 covers fertilizers containing calcium, magnesium, sodium and sulfur when they do not have declarable N, P or K contents. Clause 4.1.1.3 covers micro-nutrient fertilizers with declarable micronutrients but no declarable N, P, K, calcium, magnesium or sodium.

This matters because secondary nutrients and micronutrients are not treated as NPK fertilizers here; they have their own classification path.

4. Liming materials are defined by their soil-pH function

Clause 4.1.2 describes inorganic liming materials as soil improvers containing calcium and/or magnesium, usually as oxide, hydroxide, carbonate or silicate, intended mainly to maintain or raise soil or water pH. The scheme separates natural-origin materials from industrial products and other liming materials.

In practice, the key point is function: these products are classified as liming materials because they are used for pH control, not plant nutrition.

5. Organic fertilizers are identified by organic origin

Clause 4.2 classifies carbonaceous materials added to soil for plant nutrition when their declarable nitrogen, phosphorus or potassium comes from vegetable and/or animal origin. It includes organic nitrogenous fertilizers, synthetic organic nitrogenous fertilizers, NP, NK and NPK organic fertilizers, and products containing synthetic organic nitrogen within NP, NK or NPK fertilizers.

This helps distinguish nutrient products made from organic matter from inorganic fertilizers with the same plant-nutrition purpose.

6. Mixed-origin products have their own classes

Clause 4.3 covers organo-mineral fertilizers and organic-based fertilizers. Organo-mineral fertilizers combine organic and inorganic declared nutrients, while organic-based fertilizers contain inorganic nutrients mixed with organic materials such as peat or lignite.

For a buyer or regulator, this means the product is not forced into a purely organic or purely inorganic category when its composition is mixed.

7. National rules can affect classification details

The introduction and Figure 1 note that national legislation may affect nutrient-content limits and that some products can be classified differently in some countries. The standard also uses terms, not chemical symbols, for nutrients to avoid ambiguity between elemental and oxide forms.

That helps users compare products across borders without assuming that one national declaration practice automatically applies everywhere.

What terms does SIST EN 13535:2002 define?

SIST EN 13535:2002 uses the vocabulary from EN 12944, and Clause 4 gives classification descriptions for the main product groups.

• Inorganic fertilizers - Fertilizers with declared nutrients in inorganic salt form, obtained by extraction and/or industrial processes.
• Inorganic liming materials - Inorganic soil improvers with calcium and/or magnesium used mainly to raise or maintain pH.
• Straight nitrogenous fertilizers (N) - Fertilizers with declarable nitrogen but no declarable phosphorus or potassium.
• NPK compound fertilizers - Fertilizers with declarable nitrogen, phosphorus and potassium.
• Organo-mineral fertilizers - Products with declarable nutrients of both organic and inorganic origin.
• Organic-based fertilizers - Products with inorganic declared nutrients mixed with organic materials such as peat or lignite.
• Micro-nutrient fertilizers - Fertilizers with declarable micronutrients and no declarable N, P, K, calcium, magnesium or sodium.

Who uses SIST EN 13535:2002?

SIST EN 13535:2002 is used by people who need to classify fertilizer and liming products consistently. That includes manufacturers, product developers, laboratories, regulators, and traders working with product descriptions and national classification rules.

It is also useful for quality and compliance work, because the standard gives a common product structure for cataloguing, technical documentation, and cross-border communication.

What changed in SIST EN 13535:2002 from the previous edition?

SIST EN 13535:2002 is identical to EN 13535:2001.

Which standards are used with SIST EN 13535:2002?

SIST EN 13535:2002 uses EN 12944 (all parts), Fertilizers and liming materials - Vocabulary. EN 12944 supplies the terms and definitions that apply to this classification standard.

What does the SIST EN 13535:2002 document contain?

SIST EN 13535:2002 contains the classification scheme itself, with the hierarchical grouping shown in Figure 1. It also contains the explanatory descriptions in Clause 4 that separate inorganic fertilizers, inorganic liming materials, organic fertilizers, and mixed-origin products.

The document uses notes to explain national differences and special cases, including how some products may be treated in different countries. It is a classification document, so it is aimed at naming, grouping, and comparing fertilizer and liming materials rather than setting test methods or detailed product specifications.