FprEN 15478

• Abstract:

  This document specifies a method for the determination of the content of total nitrogen in urea, methylene-urea and urea formaldehyde in their pure form in inorganic fertilizers.

• Status: Not Published
• Publication Date: 13-Jan-2027
• ICS: 65.080 - Fertilizers
• 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: 29-Jul-2026
• Due Date: 31-Aug-2027
• Completion Date: 29-Jul-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 15478:2026 - Inorganic fertilizers - Determination of total nitrogen in urea, methylene-urea and urea formaldehyde

• Revises: EN 15478:2009 - Fertilizers - Determination of total nitrogen in urea
• Effective Date: 21-Apr-2021

Overview

FprEN 15478: Inorganic fertilizers - Determination of total nitrogen in urea, methylene-urea and urea formaldehyde is a European draft standard developed by CEN/TC 260 “Fertilizers and liming materials”. This standard specifies a method for quantitatively determining the total nitrogen content in pure forms of urea, methylene-urea, and urea formaldehyde, which are key components in inorganic fertilizers. The method applies well-established wet chemistry procedures designed to ensure high accuracy and repeatability, supporting both regulatory compliance and quality assurance in fertilizer production and trade.

Key Topics

• Determination of Total Nitrogen: The standard describes a process based on the digestion of the sample, conversion of nitrogen to ammoniacal salts, distillation, and titration to accurately quantify total nitrogen content.
• Materials Covered: The method is intended for pure forms of urea, methylene-urea, and urea formaldehyde within inorganic fertilizers.
• Analytical Procedure: The procedure involves:
  • Sample preparation following recognized guidelines
  • Digestion using sulfuric acid in presence of a catalyst
  • Distillation of ammonia
  • Back titration to determine total nitrogen
• Precision and Accuracy: Guidance on precision metrics is included, with established values for repeatability and reproducibility based on inter-laboratory studies.
• Reporting Requirements: The standard outlines comprehensive reporting criteria to ensure transparency and traceability in test results.

Applications

FprEN 15478 is relevant to a wide range of stakeholders in the fertilizer industry:

• Fertilizer Manufacturers: Enables consistent quality control and verification of nutrient content in nitrogenous fertilizers, supporting product labeling and market claims.
• Testing Laboratories: Provides detailed protocols for chemical analysis of urea, methylene-urea, and urea formaldehyde, ensuring consistency and comparability of results across laboratories.
• Regulatory Authorities: Supports regulatory compliance and enforcement by setting a clear, standardized method for determining total nitrogen content in key fertilizer types.
• Importers, Retailers, and Agricultural Consultants: Facilitates verification of declared fertilizer specifications, aiding procurement and agronomic decision-making.

Accurate determination of total nitrogen is critical for:

• Complying with European Union fertilizer regulations and standards
• Protecting farmers by ensuring fertilizers deliver expected agronomic performance
• Supporting environmental sustainability through correct nutrient management

Related Standards

The following standards should be consulted alongside FprEN 15478 for comprehensive compliance and best practices in fertilizer analysis:

• EN 1482-2: Fertilizers, liming materials and inhibitors - Sampling and sample preparation - Part 2: General sample preparation provisions
• EN 12944-1 & EN 12944-2: Fertilizers, liming materials and inhibitors - Vocabulary (Parts 1 and 2 for general and fertilizer-specific terms)
• ISO 5725-1 & ISO 5725-2: Accuracy (trueness and precision) of measurement methods and results - General principles, repeatability, and reproducibility

Practical Value

FprEN 15478 standardizes the process of total nitrogen determination for the fertilizer industry across Europe, ensuring:

• Uniformity and reliability in analytical results
• Enhanced trade confidence within the single market
• Easier regulatory compliance and audit-readiness
• Improved customer confidence in fertilizer quality

By adhering to this standard, organizations demonstrate commitment to high-quality fertilizer production, regulatory fulfillment, and sustainable agriculture practices. Use of this method will increase comparability of results between laboratories, prevent disputes over product specifications, and contribute to the responsible use of inorganic fertilizers worldwide.

Keywords: inorganic fertilizers, total nitrogen determination, urea, methylene-urea, urea formaldehyde, fertilizer analysis, European standards, CEN, fertilizer quality control, nitrogen testing, EN 15478.

SLOVENSKI STANDARD
01-april-2026
Anorganska gnojila - Določanje celotnega dušika v sečnini, metilenurei in urea
formaldehidu
Inorganic fertilizers - Determination of total nitrogen in urea, methylene-urea and urea
formaldehyde
Anorganische Düngemittel - Bestimmung des Gesamtgehalts an Stickstoff in Methylen-
Harnstoff und Harnstoff-Formaldehyd
Engrais inorganiques - Dosage de l’azote total dans l’urée, le méthylène-urée et l’urée-
formaldéhyde
Ta slovenski standard je istoveten z: prEN 15478
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
prEN 15478
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2026
ICS 65.080 Will supersede EN 15478:2009
English Version
Inorganic fertilizers - Determination of total nitrogen in
urea, methylene-urea and urea formaldehyde
Engrais inorganiques - Dosage de l'azote total dans Anorganische Düngemittel - Bestimmung des
l'urée, le méthylène-urée et l'urée-formaldéhyde Gesamtgehalts an Stickstoff in Methylen-Harnstoff und
Harnstoff-Formaldehyd
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 15478:2026 E
worldwide for CEN national Members.

prEN 15478:2026 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Reagents . 4
6 Apparatus . 5
7 Sampling and sample preparation . 10
8 Procedure . 10
8.1 Procedure for the determination of total nitrogen in urea . 10
8.1.1 Preparation of the solution . 10
8.1.2 Analysis of the solution . 10
8.1.3 Blank . 10
8.1.4 Control test . 11
8.2 Procedure for the determination of total nitrogen in methylene-urea and urea
formaldehyde . 11
8.2.1 Preparation of the solution . 11
8.2.2 Analysis of the solution . 11
8.2.3 Blank . 11
8.2.4 Control test . 11
9 Calculation and expression of the result . 12
9.1 Calculation and expression of the result of total nitrogen in urea . 12
9.2 Calculation and expression of the result of total nitrogen in methylene-urea and
urea formaldehyde . 12
10 Precision . 13
10.1 Precision of the method aiming to determine total nitrogen in urea . 13
10.1.1 Inter-laboratory study . 13
10.1.2 Repeatability . 13
10.1.3 Reproducibility . 13
10.2 Precision of the method aiming to determine total nitrogen in methylene-urea and
urea formaldehyde . 13
10.2.1 Inter-laboratory study . 13
10.2.2 Repeatability . 13
10.2.3 Reproducibility . 13
11 Test report . 14
Annex A (informative) Results of the inter-laboratory tests . 15
Annex B (informative) Results of the inter-laboratory study . 16
Bibliography . 18
prEN 15478:2026 (E)
European foreword
This document (prEN 15478:2026) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
This is currently submitted to CEN Enquiry.
This document will supersede EN 15478:2009.
prEN 15478:2026 includes the following significant technical changes with respect to EN 15478:2009:
— The scope has been broadened by adding the determination of the content of total nitrogen in
methylene-urea and urea formaldehyde and the title has been adjusted accordingly;
— The method has been technically revised according to the broader scope;
— The statistical results relating to the inter-laboratory study of the determination of total nitrogen in
methylene urea and urea formaldehyde have been added (10.2 and Annex B).
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.
prEN 15478:2026 (E)
1 Scope
This document specifies a method for the determination of the content of total nitrogen in urea,
methylene-urea and urea formaldehyde in their pure form in inorganic fertilizers.
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, Fertilizers, liming materials and inhibitors — Sampling and sample preparation — Part 2:
General sample preparation provisions
EN 12944-1, Fertilizers, liming materials and inhibitors — Vocabulary — Part 1: General terms
EN 12944-2, Fertilizers, liming materials and inhibitors — Vocabulary — Part 2: Terms relating to
fertilizers
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12944-1 and EN 12944-2
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
4 Principle
The nitrogen is transformed quantitatively into ammoniacal salt by boiling in the presence of sulfuric
acid. The ammoniacal solution thus obtained is distilled through an alkaline medium, the distillate being
collected in an excess of standard sulfuric acid. The excess acid is titrated by means of a standard
alkaline solution.
5 Reagents
Use only reagents of recognized analytical grade and distilled or demineralized water, free from carbon
dioxide and all nitrogenous compounds, having an electrical conductivity of at least < 0,5 mS/m (at
25 °C).
5.1 Kjeldahl tablets.
5.1.1 5 g/tablet containing 100 parts K SO to 1 part selenium.
2 4
or, in alternative,
5.1.2 5 g of pure K SO in powder (recommended).
2 4
5.2 Sulfuric acid, concentrated (mass concentration ρ = 1,84 g/ml).
A revision is under preparation. Stage at the time of preparation: prEN 12944-1:2026
A revision is under preparation. Stage at the time of preparation: prEN 12944-2:2026
prEN 15478:2026 (E)
5.3 Sodium hydroxide solution, NaOH, mass fraction of 30 %.
5.4 Sulfuric acid standard solution, amount-of-substance concentration c = 0,05 mol/l (0,10 N/l), to
use for the blank test in the determination of total nitrogen in urea only.
5.5 Sulfuric acid standard solution, c = 0,25 mol/l (0,5 N/l).
5.6 Sulfuric acid standard solution, c = 0,5 mol/l (1,0 N/l).
5.7 Sodium or potassium hydroxide standard solution, carbonate free, c = 0,1 mol/l, to use for the
blank test in the determination of total nitrogen in urea only.
5.8 Sodium or potassium hydroxide standard solution, carbonate free, c = 0,5 mol/l.
5.9 Sodium or potassium hydroxide standard solution, carbonate free, c = 1,0 mol/l.
5.10 Indicator for ammonia nitrogen, ready for use.
5.11 Anti-bump granules, for example pumice stone, washed in hydrochloric acid and calcined.
5.12 Urea, analytical grade.
5.13 Melamine, analytical grade.
6 Apparatus
6.1 Distillation apparatus, consisting of a round-bottomed flask of suitable capacity connected to a
condenser by means of a splash head.
The equipment is made of borosilicate glass.
NOTE The different types of equipment recommended for this determination are reproduced showing all the
features of construction in Figures 1, 2, 3, and 4.
Automatic distillation and titration apparatus may be used as well provided that the results are
statistically equivalent.
prEN 15478:2026 (E)
Dimensions in millimetres
Key
1 round-bottomed, long-necked flask of 1 000 ml capacity
2 distillation tube with a splash head, connected to the condenser by means of a spherical joint (No 18) (the
spherical joint for the connection to the condenser may be replaced by an appropriate rubber connection)
3 funnel with a polytetrafluoroethylene (PTFE) tap (6) for the addition of sodium hydroxide
4 six-bulb condenser with spherical joint (No 18) at the entrance, and joined at the issue to a glass
extension tube by means of a small rubber connection (when the connection to the distillation tube is effected by
means of a rubber tube, the spherical joint may be replaced by a suitable rubber bung)
5 500 ml flask in which the distillate is collected
6 PTFE-tap (the tap may likewise be replaced by a rubber connection with a clip)
Figure 1 — Distillation apparatus 1
prEN 15478:2026 (E)
Dimensions in millimetres
Key
1 round-bottomed, short-necked flask of 1 000 ml capacity with a spherical joint (No 35)
2 distillation tube with a splash head, equipped with a spherical joint (No 35) at the entrance and a
spherical joint (No 18) at the issue, connected at the side to a funnel with a polytetrafluoroethylene (PTFE) tap (6)
for the addition of sodium hydroxide
3 six-bulb condenser with a spherical joint (No 18) at the entrance and joined at the issue to a glass
extension tube by means of a small rubber connection
4 500 ml flask in which the distillate is collected
5 PTFE-tap
a enlarged description
Figure 2 — Distillation apparatus 2
prEN 15478:2026 (E)
Dimensions in millimetres
Key
1 round-bottomed, long-necked flask of 750
...