prEN 17752

Inorganic fertilizers - Determination of specific inhibiting compounds

This document specifies references to the methods for the determination of nitrification inhibitoring compounds and urease inhibiting compounds in inorganic fertilizers.
This document is not applicable to fertilizing products blends.

Anorganische Düngemittel - Bestimmung spezifischer Hemmstoffe

Engrais inorganiques - Détermination des composés inhibiteurs spécifiques

Le présent document spécifie les références des méthodes de détermination des composés inhibiteurs de nitrification et des composés inhibiteurs d’uréase dans les engrais inorganiques.
Le présent document n’est pas applicable aux mélanges de produits fertilisants.

Anorganska gnojila - Določanje specifičnih inhibitorjev

General Information

• Status: Not Published
• Publication Date: 09-Jan-2028
• ICS: 65.080 - Fertilizers
• Technical Committee: CEN/TC 260 - Fertilizers and liming materials
• Drafting Committee: CEN/TC 260/WG 7 - Chemical analysis
• Current Stage: 4060 - Closure of enquiry - Enquiry
• Start Date: 09-Apr-2026
• Due Date: 16-Nov-2026
• Completion Date: 09-Apr-2026
• Directive: Harmonized Standard2019/1009 - Regulation (EU) 2019/1009 of the European Parliament and of the Council of 5 June 2019 laying down rules on the making available on the market of EU fertilising products and amending Regulations (EC) No 1069/2009 and (EC) No 1107/2009 and repealing Regulation (EC) No 2003/2003 (Text with EEA relevance)
• Mandate: M/564 - Fertilising products in support of Regulation (EU) 2019/1009
• Mandate: M/564 AMD 1 - amending Implementing Decision C(2020) 612 as regards certain harmonised standards and standardisation deliverables, deadlines for their adoption and the duration of the validity of the standardisation request
• Mandate: M/564 AMD 2 - Commission Implementing decision amending Implementing Decision C(2020)612 as regards harmonised standards, the deadlines for the adoption of those standards and the duration of the validity of the standardisation request to the European Committee for Standardisation as regards the EU fertilising products in support of Regulation (EU) 2019/1009 of the European Parliament and of the Council
• Ref Project: oSIST prEN 17752:2026 - Inorganic fertilizers - Determination of specific inhibiting compounds

Relations

• Revises: CEN/TS 17752:2022 - Inorganic fertilizers - Determination of specific inhibitors
• Effective Date: 03-Jul-2024

Overview

prEN 17752: Inorganic Fertilizers - Determination of Specific Inhibiting Compounds sets out standardized references for testing and determining the presence and content of nitrification inhibiting compounds and urease inhibiting compounds in inorganic fertilizers. Developed by the European Committee for Standardization (CEN/TC 260), this draft European Standard aims to support regulatory compliance, ensure product safety, and help stakeholders meet the provisions of Regulation (EU) 2019/1009 for EU fertilizing products. The standard explicitly excludes blends of fertilizing products from its scope.

Key Topics

• Nitrification inhibitors: Substances designed to slow the conversion of ammonium to nitrate, maintaining nitrogen in the soil for longer periods and reducing nitrogen losses.
  • Compounds covered include:
    • Dicyandiamide
    • 3-methylpyrazole (MP)
    • 1H-1,2,4-triazole
    • 3,4-dimethyl-1H-pyrazole phosphate (DMPP)
    • 2-(3,4-dimethyl-pyrazol-1-yl)-succinic acid (DMPSA)
• Urease inhibitors: Compounds that minimize the rate at which urea is converted to ammonia, increasing nitrogen use efficiency.
  • Compounds detailed:
    • N-(n-butyl)thiophosphoric triamide (NBPT)
    • N-(2-nitrophenyl)phosphoric triamide (2-NPT)
    • N-(n-propyl)thiophosphoric triamide (NPPT)
• Referenced methods: Provides the references to standardized test methods based primarily on high-performance liquid chromatography (HPLC) for each compound.
• Sampling and preparation: Refers to general EN standards for sample handling to ensure representativity and avoid sample alteration.
• Regulatory alignment: Supports compliance with Regulation (EU) 2019/1009, linking the testing of inhibiting compounds in inorganic fertilizers to essential safety and quality requirements.

Applications

The practical applications of prEN 17752 are significant for professionals in the fertilizer manufacturing, quality control, and regulatory compliance sectors, including:

• Quality assurance: Ensuring that inorganic fertilizers contain the specified types and quantities of inhibiting compounds, supporting product claims and consistency.
• Regulatory compliance: Facilitating conformity assessments with Regulation (EU) 2019/1009, particularly in relation to product function categories (e.g., PFC 1(C)), by applying referenced test methods in Annex III of the regulation.
• Research and development: Supporting innovation in fertilizer formulations through reliable determination of inhibiting additives, enabling performance verification during R&D.
• Market access in the EU: Serving as a route to demonstrate conformity with EU requirements, thereby enabling manufacturers to legally market inorganic fertilizers with specified inhibitors across participating European countries.

Related Standards

To ensure reliable and comparable results, prEN 17752 references several established European standards for terminology, sampling, sample preparation, and analytical methods, including:

• EN 1482 series: Fertilizers - Sampling and Sample Preparation (Parts 1-3)
• EN 12944 series: Fertilizers and Liming Materials - Vocabulary
• EN 15360:2007: Determination of Dicyandiamide by HPLC
• EN 15905:2010: 3-methylpyrazole (MP) Determination by HPLC
• EN 16024:2011: 1H-1,2,4-triazole Determination by HPLC
• EN 16328:2012: DMPP Determination by HPLC
• EN 17090:2018: DMPSA Determination by HPLC
• EN 15688:2008 & EN 16651:2015: NBPT and NPPT Determination by HPLC
• EN 16075:2011: 2-NPT Determination by HPLC

By referencing these harmonized methodologies, prEN 17752 ensures consistency, accuracy, and credibility in the determination of specific inhibiting compounds within inorganic fertilizers for the European marketplace.

Keywords: prEN 17752, inorganic fertilizers, nitrification inhibitors, urease inhibitors, fertilizer testing, EU Regulation 2019/1009, CEN, fertilizer analysis, HPLC, European standard, fertilizer compliance, fertilizer quality.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2026
Anorganska gnojila - Določanje specifičnih inhibitorjev
Inorganic fertilizers - Determination of specific inhibiting compounds
Anorganische Düngemittel - Bestimmung spezifischer Hemmstoffe
Engrais inorganiques - Détermination des composés inhibiteurs spécifiques
Ta slovenski standard je istoveten z: prEN 17752
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2026
ICS 65.080 Will supersede CEN/TS 17752:2022
English Version
Inorganic fertilizers - Determination of specific inhibiting
compounds
Engrais inorganiques - Détermination des composés Anorganische Düngemittel - Bestimmung spezifischer
inhibiteurs spécifiques Hemmstoffe
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 17752:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Sampling and sample preparation . 6
4.1 Sampling . 6
4.2 Sample preparation . 6
5 Determination of specific inhibiting compounds . 6
5.1 Determination of the nitrification inhibiting compound content . 6
5.1.1 Determination of dicyandiamide . 6
5.1.2 Determination of 3-methylpyrazole (MP) . 6
5.1.3 Determination of 1H-1,2,4-triazole . 6
5.1.4 Determination of 3,4-dimethyl-1H-pyrazole phosphate (DMPP) . 6
5.1.5 Determiantion of 2-(3,4-dimethyl-pyrazol-1-yl)-succinic acid (DMPSA) . 6
5.2 Determination of the urease inhibiting compound content . 7
5.2.1 Determination of N-(n-butyl)thiophosphoric triamide (NBPT) . 7
5.2.2 Determination of N-(2-nitrophenyl)phosphoric triamide (2-NPT) . 7
5.2.3 Determination of N-(n-butyl)thiophosphoric triamide (NBPT) and N-(n-
propyl)thiophosphoric triamide (NPPT) . 7
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 . 8
Bibliography . 9

European foreword
This document (prEN 17752:2026) 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 17752:2022.
Compared to the previous edition, prEN 17752:2025 includes the following significant technical changes:
a) the CEN Technical Specification has been adopted as a European Standard including the addition of
Annex ZA;
b) the Scope (Clause 1) has been updated with respect to fertilizing product blends;
c) the normative references (Clause 2) and the Bibliography have been updated.
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.
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 fertiliziers have been classified into PFC 1(C).
The specific safety and quality requirements 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 parameter in the
Regulation (EU) 2019/1009 [1].
...