FprEN 17757
(Main)Inorganic fertilizers - Determination of specific nutrients
- Abstract
This document specifies references to methods for the determination of the content of the following specific nutrients in inorganic fertilizers:
— the total nitrogen content;
— the ammoniacal nitrogen content;
— the nitric nitrogen content;
— the urea nitrogen content;
— the content of nitrogen from isobutylidenediurea (IBDU) and crotonylidenediurea (CDU);
— the cyanamide nitrogen content;
— the methylene-urea nitrogen content (and urea formaldehyde, if applicable);
— the total phosphorus content;
— the water-soluble phosphorus content;
— the neutral ammonium citrate soluble phosphorus content;
— the formic acid soluble phosphorus content;
— the total potassium content;
— the water-soluble potassium content;
— the total magnesium content;
— the water-soluble magnesium content;
— the total calcium content;
— the water-soluble calcium content;
— the total sulfur content;
— the water-soluble sulfur content;
— the total sodium content;
— the water-soluble sodium content.
This document is applicable to the fertilizing products blends where a blend is a mix of at least two of the following components: fertilizers, liming materials, soil improvers, growing media, inhibitors, plant biostimulants, and where the following category: inorganic fertilizers is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If inorganic fertilizer is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply. Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.
- Status
- Not Published
- Publication Date
- 24-Feb-2027
- Technical Committee
- CEN/TC 260 - Fertilizers and liming materials
- Drafting Committee
- CEN/TC 260/WG 7 - Chemical analysis
- Current Stage
- 4599 - Dispatch of FV draft to CMC - Finalization for Vote
- Start Date
- 28-Aug-2026
- Due Date
- 31-Aug-2027
- Completion Date
- 28-Aug-2026
FprEN 17757 is a CEN draft European Standard for inorganic fertilizers. It specifies which analytical methods to use for determining specific nutrients in those products, including several forms of nitrogen plus phosphorus, potassium, magnesium, calcium, sulfur, and sodium. It is aimed at users who need a common basis for nutrient testing, product control, and compliance work.
What does FprEN 17757 specify?
FprEN 17757 specifies references to methods for determining specific nutrients in inorganic fertilizers and in certain fertilizing product blends. It does not give one single test for all products - instead, it tells the user which existing standard to apply for each nutrient form and matrix.
The document is organized into:
- Clause 1 - scope
- Clause 2 - normative references
- Clause 3 - terms and definitions
- Clause 4 - sampling and sample preparation
- Clause 5 - methods for extraction and determination of specific nutrients
- Annex ZA - relationship with Regulation (EU) 2019/1009
- Bibliography
| Annex | What it covers |
|---|---|
| ZA | Relationship between this European Standard and the essential requirements of Regulation (EU) 2019/1009 |
Clause 1 also sets the blend rule for fertilizing product blends. Where inorganic fertilizers are the highest percentage component, this standard applies; otherwise, the standard for the highest-percentage component applies. If components are present in equal quantity, the user chooses the standard. This matters because matrix effects can change analytical results.
What are the key requirements of FprEN 17757?
FprEN 17757 is mainly a method-selection standard. The practical requirement is to identify the nutrient form in the product, then use the matching referenced method.
Sampling and sample preparation
Clause 4 says sampling is not part of the method in this document. Sample preparation shall follow EN 1482-2:2024, and sampling guidance is given in EN 1482-1 and EN 1482-3. In practice, the laboratory needs a representative sample that has not been changed by transport or storage.
Nitrogen
Clause 5.1 selects different methods according to the nitrogen form and product type. For example, it points to EN 15560:2023 and EN 15561:2023 for calcium cyanamide products, prEN 15478:2026 for urea and for methylene-urea and urea formaldehyde nitrogen, EN 15750:2009 for fertilizers containing only nitric, ammoniacal and urea nitrogen, EN 15604:2009 for mixed nitrogen forms, and EN 15476:2009 for fertilizers with only nitric and ammoniacal nitrogen. This means the user must match the method to the fertilizer chemistry, not just to the label claim.
Clause 5.2 uses prEN 15475:2026 for ammoniacal nitrogen, clause 5.5 uses EN 17864:2023 for nitrogen from IBDU and CDU, and clause 5.6 uses EN 15562:2023 for cyanamide nitrogen. Clause 5.4 notes that EN 15604:2009 is not validated for products containing cyanamide nitrogen.
Phosphorus, potassium, magnesium, calcium, sulfur and sodium
Clause 5.8 distinguishes the phosphorus fraction to be measured: total phosphorus via prEN 15956:2026, water-soluble phosphorus via EN 15958:2011, neutral ammonium citrate soluble phosphorus via prEN 15957:2026, formic acid soluble phosphorus via EN 15919:2011, and extracted phosphorus via EN 15959:2023. Clause 5.9 does the same for potassium, using EN 15477:2009 for water-soluble potassium and prEN 18316:2026 for total potassium.
Clauses 5.10 to 5.13 cover magnesium, calcium, sulfur and sodium. They use prEN 15960:2025 and prEN 15961:2025 for extraction, then EN 16197:2012, EN 16198:2012, EN 16196:2012 and EN 16199:2012 for determination where specified. For sulfur, the document distinguishes sulfate forms from sulfur present in several forms, so the chosen method depends on the chemistry of the sample.
Regulatory use
Annex ZA links the standard to Regulation (EU) 2019/1009. When the standard is cited in the Official Journal of the European Union, the clauses listed in Table ZA.1 support presumption of conformity within the scope of the standard. For users, that means the test result can be used directly in conformity work for EU fertilising products.
What terms does FprEN 17757 define?
- PFC 1(C) - the product function category for inorganic fertilizers under Regulation (EU) 2019/1009.
- IBDU - isobutylidenediurea, a nitrogen compound measured together with CDU in clause 5.5.
- CDU - crotonylidenediurea, another slow-release nitrogen compound covered by the same method as IBDU.
- Fertilizing product blends - mixes of at least two listed component types, including fertilizers, liming materials, soil improvers, growing media, inhibitors, and plant biostimulants.
- Neutral ammonium citrate soluble phosphorus - the phosphorus fraction extracted by neutral ammonium citrate before determination.
- Water-soluble nutrient - the portion that can be extracted in water and measured as the soluble fraction.
Who uses FprEN 17757?
FprEN 17757 is used by fertilizer manufacturers, testing laboratories, quality control teams, and conformity assessment bodies. It helps them choose the correct method for nutrient analysis, compare results across products, and support compliance checks for inorganic fertilizers and qualifying blends. Buyers and specifiers can also use it to understand which test methods sit behind nutrient declarations.
What changed in FprEN 17757 from the previous edition?
FprEN 17757 will supersede CEN/TS 17757:2022. The document states these significant changes:
- adoption as a European Standard, including Annex ZA
- updated Scope
- updated Normative references
- updated Bibliography
- addition of formic acid soluble phosphorus content
- addition of total potassium content
Which standards are used with FprEN 17757?
| Reference(s) | What they contribute |
|---|---|
| EN 1482-1, EN 1482-2, EN 1482-3 | sampling guidance and sample preparation |
| prEN 12944-1, prEN 12944-2 | vocabulary for fertilizers and related products |
| Nitrogen methods: prEN 15475, EN 15476, prEN 15478, EN 15560, EN 15561, EN 15562, EN 15604, EN 15750, EN 17864 | methods for ammoniacal, nitric, urea, cyanamide, mixed and IBDU/CDU nitrogen forms |
| Phosphorus methods: EN 15919, EN 15956, prEN 15957, EN 15958, EN 15959 | extraction and determination of phosphorus fractions |
| Potassium methods: EN 15477, prEN 18316 | water-soluble and total potassium |
| Magnesium, calcium, sodium methods: prEN 15960, prEN 15961, EN 16196, EN 16197, EN 16198, EN 16199 | extraction and determination of these nutrients |
| Sulfur methods: prEN 15925, EN 15926, EN 15749 | sulfur extraction and determination in different chemical forms |
What does the FprEN 17757 document contain?
FprEN 17757 contains the scope, the reference list, the terms section, and a short procedure map for sampling, sample preparation, and nutrient-specific analysis. Clause 5 is organized by nutrient group, so the reader can move from nitrogen to phosphorus, potassium, magnesium, calcium, sulfur and sodium without reading a full method from scratch.
The document also contains Annex ZA, which ties the analytical clauses to Regulation (EU) 2019/1009. The bibliography points to the regulation and to the sampling standards that support practical laboratory work.
Relations
- Effective Date
- 03-Jul-2024
Get Certified
Connect with accredited certification bodies for this standard
Control Union Certifications
Global certification for agriculture and sustainability.
ECOCERT
Organic and sustainability certification.
FSC International
Forest Stewardship Council certification.
Sponsored listings
Frequently Asked Questions
FprEN 17757 is a draft published by the European Committee for Standardization (CEN). Its full title is "Inorganic fertilizers - Determination of specific nutrients". This standard covers: This document specifies references to methods for the determination of the content of the following specific nutrients in inorganic fertilizers: — the total nitrogen content; — the ammoniacal nitrogen content; — the nitric nitrogen content; — the urea nitrogen content; — the content of nitrogen from isobutylidenediurea (IBDU) and crotonylidenediurea (CDU); — the cyanamide nitrogen content; — the methylene-urea nitrogen content (and urea formaldehyde, if applicable); — the total phosphorus content; — the water-soluble phosphorus content; — the neutral ammonium citrate soluble phosphorus content; — the formic acid soluble phosphorus content; — the total potassium content; — the water-soluble potassium content; — the total magnesium content; — the water-soluble magnesium content; — the total calcium content; — the water-soluble calcium content; — the total sulfur content; — the water-soluble sulfur content; — the total sodium content; — the water-soluble sodium content. This document is applicable to the fertilizing products blends where a blend is a mix of at least two of the following components: fertilizers, liming materials, soil improvers, growing media, inhibitors, plant biostimulants, and where the following category: inorganic fertilizers is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If inorganic fertilizer is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply. Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.
This document specifies references to methods for the determination of the content of the following specific nutrients in inorganic fertilizers: — the total nitrogen content; — the ammoniacal nitrogen content; — the nitric nitrogen content; — the urea nitrogen content; — the content of nitrogen from isobutylidenediurea (IBDU) and crotonylidenediurea (CDU); — the cyanamide nitrogen content; — the methylene-urea nitrogen content (and urea formaldehyde, if applicable); — the total phosphorus content; — the water-soluble phosphorus content; — the neutral ammonium citrate soluble phosphorus content; — the formic acid soluble phosphorus content; — the total potassium content; — the water-soluble potassium content; — the total magnesium content; — the water-soluble magnesium content; — the total calcium content; — the water-soluble calcium content; — the total sulfur content; — the water-soluble sulfur content; — the total sodium content; — the water-soluble sodium content. This document is applicable to the fertilizing products blends where a blend is a mix of at least two of the following components: fertilizers, liming materials, soil improvers, growing media, inhibitors, plant biostimulants, and where the following category: inorganic fertilizers is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If inorganic fertilizer is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply. Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.
FprEN 17757 is classified under the following ICS (International Classification for Standards) categories: 65.080 - Fertilizers. The ICS classification helps identify the subject area and facilitates finding related standards.
FprEN 17757 has the following relationships with other standards: It is inter standard links to CEN/TS 17757:2022. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
FprEN 17757 is associated with the following European legislation: EU Directives/Regulations: 2019/1009; Standardization Mandates: M/564, M/564 AMD 1, M/564 AMD 2. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
FprEN 17757 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2026
Anorganska gnojila - Določanje specifičnih hranil
Inorganic fertilizers - Determination of specific nutrients
Anorganische Düngemittel - Bestimmung spezifischer Nährstoffe
Engrais inorganiques - Détermination des éléments nutritifs spécifiques
Ta slovenski standard je istoveten z: prEN 17757
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
prEN 17757
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2026
ICS 65.080 Will supersede CEN/TS 17757:2022
English Version
Inorganic fertilizers - Determination of specific nutrients
Engrais inorganiques - Détermination des éléments Anorganische Düngemittel - Bestimmung spezifischer
nutritifs spécifiques Nährstoffe
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 260.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17757:2026 E
worldwide for CEN national Members.
prEN 17757:2026 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 6
3 Terms and definitions . 7
4 Sampling and sample preparation . 7
4.1 Sampling . 7
4.2 Sample preparation . 7
5 Methods for extraction and determination of specific nutrients . 7
5.1 Total nitrogen content . 7
5.2 Ammoniacal nitrogen . 8
5.3 Nitric nitrogen . 8
5.4 Urea nitrogen content . 8
5.5 Content of nitrogen from IBDU and CDU . 8
5.6 Cyanamide nitrogen content . 8
5.7 Methylene-urea and urea formaldehyde nitrogen content . 8
5.8 Phosphorus content . 8
5.9 Potassium content . 8
5.10 Magnesium content . 9
5.11 Calcium content . 9
5.12 Sulfur content . 9
5.13 Sodium content . 9
Annex ZA (informative) Relationship of this European Standard and the essential
requirements of Regulation (EU) 2019/1009 making available on the market of EU
fertilising products aimed to be covered . 10
Bibliography . 16
prEN 17757:2026 (E)
European foreword
This document (prEN 17757:2026) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
This document is currently submitted to CEN Enquiry.
This document will supersede CEN/TS 17757:2022.
prEN 17757:2026 includes the following significant technical changes with respect to
CEN/TS 17757:2022:
a) the CEN Technical Specification has been adopted as a European Standard including the addition of
Annex ZA;
b) Scope (Clause 1) updated:
c) Normative references (Clause 2) updated;
d) Bibliography updated;
e) determination of formic acid soluble phosphorus content (5.8) and total potassium content (5.9)
added.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
For the relationship with EU Legislation, see informative Annex ZA, which is an integral part of this
document.
prEN 17757:2026 (E)
Introduction
Regulation (EU) 2019/1009 [1] lays down the rules on the making available on the market of EU
fertilizing products and the specific safety and quality requirements for the defined product function
categories (PFCs). Inorganic fertilizers have been classified into PFC 1(C).
The specific safety and quality requirements in relation to the following specific nutrients are defined in
this document as well as normative references of the test methods to be used in order to measure the
compliance with the related requirement in the Regulation (EU) 2019/1009 [1].
prEN 17757:2026 (E)
1 Scope
This document specifies references to methods for the determination of the content of the following
specific nutrients in inorganic fertilizers:
— the total nitrogen content;
— the ammoniacal nitrogen content;
— the nitric nitrogen content;
— the urea nitrogen content;
— the content of nitrogen from isobutylidenediurea (IBDU) and crotonylidenediurea (CDU);
— the cyanamide nitrogen content;
— the methylene-urea nitrogen content (and urea formaldehyde, if applicable);
— the total phosphorus content;
— the water-soluble phosphorus content;
— the neutral ammonium citrate soluble phosphorus content;
— the formic acid soluble phosphorus content;
— the total potassium content;
— the water-soluble potassium content;
— the total magnesium content;
— the water-soluble magnesium content;
— the total calcium content;
— the water-soluble calcium content;
— the total sulfur content;
— the water-soluble sulfur content;
— the total sodium content;
— the water-soluble sodium content.
This document is applicable to the fertilizing products blends where a blend is a mix of at least two of the
following components: fertilizers, liming materials, soil improvers, growing media, inhibitors, plant
biostimulants, and where the following category: inorganic fertilizers is the highest % in the blend by
mass or volume, or in the case of liquid form by dry mass. If inorganic fertilizer is not the highest % in the
blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is
composed of components in equal quantity, the user decides which standard to apply. Variations in
analytical methods for fertilizing product blends can lead to differing results as some components or
matrix interactions can affect the outcome. Validation procedures have shown that developed standard
prEN 17757:2026 (E)
methods are robust and reliable across diverse product compositions, but possible interferences and
unexpected results when analysing fertilizing product blends are possible.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1482-2:2024, Fertilizers, liming materials and inhibitors — Sampling and sample preparation — Part
2: General sample preparation provisions
prEN 12944-1:2026, Fertilizers, liming materials and inhibitors — Vocabulary — Part 1: General terms
prEN 12944-2:2026, Fertilizers, liming materials and inhibitors — Vocabulary — Part 2: Terms relating to
fertilizers
prEN 15475:2026, Inorganic fertilizers — Titrimetric determination of ammoniacal nitrogen
EN 15476:2009, Fertilizers — Determination of nitric and ammoniacal nitrogen according to Devarda
EN 15477:2009, Fertilizers — Determination of the water-soluble potassium content
prEN 15478:2026, Inorganic fertilizers — Determination of total nitrogen in urea, methylene-urea and
urea formaldehyde
EN 15560:2023, Inorganic fertilizers — Determination of total nitrogen in calcium cyanamide nitrate free
EN 15561:2023, Inorganic fertilizers — Determination of total nitrogen in calcium cyanamide containing
nitrates
EN 15562:2023, Inorganic fertilizers — Determination of cyanamide nitrogen
EN 15604:2009, Fertilizers — Determination of different forms of nitrogen in the same sample, containing
nitrogen as nitric, ammoniacal, urea and cyanamide nitrogen
EN 15749:2022, Fertilizers — Determination of sulfates content using three different methods
EN 15750:2009, Fertilizers — Determination of total nitrogen in fertilizers containing nitrogen only as
nitric, ammoniacal and urea nitrogen by two different methods
EN 15919:2011, Fertilizers — Extraction of phosphorus soluble in 2 % formic acid
prEN 15925:2026, Inorganic fertilizers — Extraction of total sulfur present in various forms
EN 15926:2011, Fertilizers — Extraction of water soluble sulfur where the sulfur is in various forms
prEN 15956:2025, Inorganic fertilizers — Extraction of phosphorus soluble in mineral acids
prEN 15957:2026, Inorganic fertilizers — Extraction of phosphorus which is soluble in neutral ammonium
citrate
EN 15958:2011, Fertilizers — Extraction of water soluble phosphorus
EN 15959:2023, Inorganic fertilizers — Determination of extracted phosphorus P O
2 5
prEN 17757:2026 (E)
prEN 15960:2025, Inorganic fertilizers — Extraction of total calcium, total magnesium, total sodium and
total sulfur in the forms of sulfates
prEN 15961:2025, Inorganic fertilizers — Extraction of water-soluble calcium, magnesium, sodium and
sulfur in the form of sulfates
EN 16196:2012, Fertilizers — Manganimetric determination of extracted calcium following precipitation
in the form of oxalate
EN 16197:2012, Fertilizers — Determination of magnesium by atomic absorption spectrometry
EN 16198:2012, Fertilizers — Determination of magnesium by complexometry
EN 16199:2012, Fertilizers — Determination of the sodium extracted by flame-emission spectrometry
EN 17864:2023, Inorganic fertilizers — Determination of nitrogen content in IBDU (isobutylidenediurea)
and CDU (crotonylidenediurea)
prEN 18316
...