kSIST FprEN 18318:2026
(Main)Organo-mineral fertilizers - Determination of specific inhibiting compounds
- Abstract
This document specifies references to methods for determining the content of urease inhibiting compounds in organo-mineral fertilizers.
This document is applicable to fertilizing product blends where the blend is a mix of at least two of the following components: organic fertilizers and inorganic fertilizers to which urease inhibitors have been added.
This document is not applicable to fertilizing product blends containing liming materials, soil conditioners, growing media or plant biostimulants.
- Status
- Not Published
- Public Enquiry End Date
- 01-May-2026
- Technical Committee
- KAT - Soil quality
- Current Stage
- 5020 - Formal vote (FV) (Adopted Project)
- Start Date
- 03-Nov-2026
- Due Date
- 22-Dec-2026
kSIST FprEN 18318:2026 is the SIST publication of the draft European Standard prEN 18318:2026. It covers organo-mineral fertilizers and specifies which methods to use for determining specific urease inhibiting compounds. In practice, it is for laboratories, manufacturers, and conformity teams that need to check urease inhibitor content in organo-mineral fertilizer blends.
What does kSIST FprEN 18318:2026 specify?
kSIST FprEN 18318:2026 specifies references to methods for determining the content of urease inhibiting compounds in organo-mineral fertilizers. The document is organized into scope, normative references, terms and definitions, sampling and sample preparation, determination methods, and an informative Annex ZA linked to EU fertiliser legislation.
It applies to fertilizing product blends made from at least two of these components: organic fertilizers and inorganic fertilizers to which urease inhibitors have been added. It excludes blends containing liming materials, soil conditioners, growing media, or plant biostimulants.
What are the key requirements of kSIST FprEN 18318:2026?
Applicability of the document
kSIST FprEN 18318:2026 is limited to organo-mineral fertilizer blends that combine the specified fertilizer components and include urease inhibitors. That matters because users need to confirm the product falls within the scope before applying the analytical references.
The document also states that sampling is not part of the method itself. That means the laboratory result depends on using an appropriate sampling approach before any analysis begins.
Sampling and sample preparation
kSIST FprEN 18318:2026 points users to a recommended sampling method in EN 1482-1 and requires sample preparation in accordance with EN 1482-2:2024. In practice, this means the test sample must represent the product actually being assessed.
The document also emphasizes that the laboratory sample should not be damaged or altered during transport or storage. That is important because changes before testing can distort the measured inhibitor content.
Determination of specific compounds
kSIST FprEN 18318:2026 identifies separate methods for the two named urease inhibiting compounds. N-(n-butyl)thiophosphoric triamide (NBPT) is determined according to prEN 18317:2026, while N-(2-nitrophenyl)phosphoric triamide (2-NPT) is determined according to EN 16075:2011.
This structure matters because the document itself is a reference standard, not a full test method. Users need the cited method standard for the actual analytical work.
Legal and conformity link
kSIST FprEN 18318:2026 includes informative Annex ZA, which links the standard to Regulation (EU) 2019/1009 on EU fertilising products. When cited in the Official Journal of the European Union, the normative clauses in scope can support presumption of conformity with the corresponding essential requirements.
That makes the document relevant not only for testing, but also for demonstrating compliance in the EU market framework.
What terms does kSIST FprEN 18318:2026 define?
- Organo-mineral fertilizers - The product type covered by the document; the introduction places them in product function category PFC 1(B).
- Urease inhibiting compounds - The active compounds the document is concerned with measuring in organo-mineral fertilizers.
- NBPT - Short form for N-(n-butyl)thiophosphoric triamide, one of the compounds covered by Clause 5.
- 2-NPT - Short form for N-(2-nitrophenyl)phosphoric triamide, the second compound covered by Clause 5.
- Sample preparation - The preparation step required before testing, carried out according to EN 1482-2:2024.
- PFC 1(B) - The EU product function category mentioned in the introduction for organo-mineral fertilizers.
Who uses kSIST FprEN 18318:2026?
kSIST FprEN 18318:2026 is used by analytical laboratories, fertilizer manufacturers, quality managers, and conformity assessment teams. They use it to choose the correct test method for NBPT and 2-NPT and to prepare evidence for product compliance.
It is also relevant to organizations working with EU fertilising products under Regulation (EU) 2019/1009. For them, the document helps connect laboratory measurements with market-access and compliance checks.
Which standards are used with kSIST FprEN 18318:2026?
- EN 1482-2:2024 - Gives the general sample preparation provisions required by Clause 4.2.
- EN 1482-1 - Gives the recommended sampling method mentioned in Clause 4.1.
- prEN 12944-1:2026 - Provides general vocabulary used for the terms and definitions in Clause 3.
- prEN 12944-2:2026 - Provides fertilizer-related vocabulary used for the terms and definitions in Clause 3.
- prEN 18317:2026 - Gives the method for determining NBPT content.
- EN 16075:2011 - Gives the HPLC method for determining 2-NPT content.
What does the kSIST FprEN 18318:2026 document contain?
kSIST FprEN 18318:2026 contains a short technical structure focused on method references rather than a full analytical procedure. Clause 4 covers sampling and sample preparation, and Clause 5 separates the determination of NBPT and 2-NPT.
Annex ZA provides the link between the standard and Regulation (EU) 2019/1009. The bibliography points readers to the related EU fertiliser regulation and the sampling part EN 1482-1.
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Frequently Asked Questions
kSIST FprEN 18318:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Organo-mineral fertilizers - Determination of specific inhibiting compounds". This standard covers: This document specifies references to methods for determining the content of urease inhibiting compounds in organo-mineral fertilizers. This document is applicable to fertilizing product blends where the blend is a mix of at least two of the following components: organic fertilizers and inorganic fertilizers to which urease inhibitors have been added. This document is not applicable to fertilizing product blends containing liming materials, soil conditioners, growing media or plant biostimulants.
This document specifies references to methods for determining the content of urease inhibiting compounds in organo-mineral fertilizers. This document is applicable to fertilizing product blends where the blend is a mix of at least two of the following components: organic fertilizers and inorganic fertilizers to which urease inhibitors have been added. This document is not applicable to fertilizing product blends containing liming materials, soil conditioners, growing media or plant biostimulants.
kSIST FprEN 18318:2026 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.
kSIST FprEN 18318:2026 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.
kSIST FprEN 18318:2026 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
oSIST prEN 18318:2026
01-april-2026
Organsko-mineralna gnojila - Določanje specifičnih inhibitorjev
Organo-mineral fertilizers - Determination of specific inhibiting compounds
Organisch-mineralische Düngemittel - Bestimmung spezifischer Hemmstoffe
Engrais organo-minéraux - Détermination des composés inhibiteurs spécifiques
Ta slovenski standard je istoveten z: prEN 18318
ICS:
65.080 Gnojila Fertilizers
oSIST prEN 18318:2026 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN 18318:2026
oSIST prEN 18318:2026
DRAFT
EUROPEAN STANDARD
prEN 18318
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2026
ICS 65.080
English Version
Organo-mineral fertilizers - Determination of specific
inhibiting compounds
Engrais organo-minéraux - Détermination des Organisch-mineralische Düngemittel - Bestimmung
composés inhibiteurs spécifiques spezifischer 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 18318:2026 E
worldwide for CEN national Members.
oSIST prEN 18318:2026
prEN 18318:2026 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Sampling and sample preparation . 5
4.1 Sampling . 5
4.2 Sample preparation . 5
5 Determination of the urease inhibiting compound content . 6
5.1 Determination of N-(n-butyl)thiophosphoric triamide (NBPT). 6
5.2 Determination of N-(2-nitrophenyl)phosphoric triamide (2-NPT) . 6
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 . 7
Bibliography . 8
oSIST prEN 18318:2026
prEN 18318:2026 (E)
European foreword
This document (prEN 18318:2026) 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 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.
oSIST prEN 18318:2026
prEN 18318:2026 (E)
Introduction
Different product functions warrant different product safety and quality requirements adapted to their
...