CEN/TS 16490:2013

SLOVENSKI STANDARD
01-maj-2013
Gnojila - Primerjava rezultatov krožnih preskusov CEN/TC 260/WG 7 z dovoljenimi
odstopanji, navedenimi v Uredbi (ES) št. 2003/2003 Priloga II in sklepi
Fertilizers - Comparison of the CEN/TC 260/WG 7 ring test results with tolerances given
in the Regulation (EC) Nr 2003/2003 Annex II and conclusions
Düngemittel - Vergleich der Ringversuchsergebnisse der CEN/TC 260/WG 7 mit den in
der Verordnung (EG) Nr. 2003/2003 Anhang II angegebenen Toleranzen und
Schlussfolgerungen
Engrais - Comparaison des résultats des essais interlaboratoires menés par le CEN/TC
260/WG 7 avec les tolérances données dans le règlement (CE) n°2003/2003 Annexe II
et conclusions
Ta slovenski standard je istoveten z: CEN/TS 16490:2013
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN/TS 16490
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
April 2013
ICS 65.080
English Version
Fertilizers - Comparison of the CEN/TC 260/WG 7 ring test
results with tolerances given in the Regulation (EC) Nr
2003/2003 Annex II and conclusions
Engrais - Comparaison des résultats des essais Düngemittel - Vergleich der Ringversuchsergebnisse der
interlaboratoires menés par le CEN/TC 260/WG 7 avec les CEN/TC 260/WG 7 mit den in der Verordnung (EG) Nr.
tolérances données dans le règlement (CE) n°2003/2003 2003/2003 Anhang II angegebenen Toleranzen und
Annexe II et conclusions Schlussfolgerungen
This Technical Specification (CEN/TS) was approved by CEN on 12 February 2013 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 16490:2013: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Statistical method validation .6
4.1 General .6
4.2 Approach taken by CEN/TC 260/WG 7 .6
4.3 Statistical data: results versus tolerances .6
4.4 Refined statistical analysis .7
4.5 Field data .7
5 Conclusions .8
Annex A (informative) Statistical data of the inter-laboratory tests and findings . 10
A.1 General . 10
A.2 Nitrogen . 10
A.3 Phosphate . 13
A.4 Potassium . 15
A.5 Sulfur . 15
A.6 Chloride . 18
A.7 Secondary nutrients . 18
Annex B (informative) Refined statistical evaluation . 26
B.1 General . 26
B.2 Meaning of symbols . 26
B.3 Tolerances for SO . 27
B.4 Tolerances for CaO, MgO. Na O and Cl . 28
B.5 Refinement of results . 32
B.6 Comments . 32
Bibliography . 33

Foreword
This document (CEN/TS 16490:2013) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cyprus,
Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,
Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Introduction
Following a request from the European Commission (Mandate M/418), an evaluation was done of the existing
tolerances as per Regulation (EC) No. 2003/2003. Input for this evaluation was derived from the precision
data obtained via the several ring tests that have been made according to Mandate M/335.
As to exclude eventual interference from effects due to inhomogeneity of physically blended grades, no blends
have been included in the ring tests; test samples have been limited and chosen as to be representing some
main product grades sold within the EU.
The statistical evaluation has been done in line with ISO 5725-2 and whenever deemed necessary for
appropriate evaluation and interpretation of the test results, some extra statistical evaluation was made on the
test data.
As to judge to what extent problems arise in case of enforcement controls, some field data have been
analysed as to verify to what extent actual conflicts exist in between test results from official controls and
applied tolerances.
The evaluation revealed no real need for adjustments to tolerances as they relate to analytical variability.
However, it should be emphasised that the tolerances given in Regulation 2003/2003 relate not only to
analytical variability but to the total variability including allowances for sampling error and product variability.
Finally if the European Commission sees the necessity of further method improvements, then one could
consider a project entitled to develop an alternative method. Only following a full evaluation including ring
testing, a final judgment can be made if the newly developed method could be a candidate for replacement of
the existing one(s) assuming better accuracy data.
1 Scope
In Regulation (EC) No. 2003/2003 [2] tolerance limits are mentioned for nutrient contents in mineral fertilizers
(Annex II of Regulation (EC) No. 2003/2003) as well as prescribed methods for control purposes (Annex IV of
Regulation (EC) No. 2003/2003).
Prior to the work done by CEN/TC 260 following Mandate M/335, no statistical data were available for the
official analytical methods to be applied. Due to the standardization work done for this mandate, statistical
data have been generated as ring testing was a major topic in this mandate.
This Technical Specification describes to what extent the presently applied tolerances are in line with the
obtained precision data from the analytical methods studied.
The purpose of this document is to give feedback on the applied tolerances within Regulation (EC)
No. 2003/2003 based on the method evaluation done as an outcome of the work executed by
CEN/TC 260/WG 7 according to Mandate M/335. This evaluation of the tolerances was part of Mandate
M/418.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 5725-1:1994, Accuracy (trueness and precision) of measurement methods and results — Part 1: General
principles and definitions
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
tolerance (T)
variation including manufacturing, raw materials, sampling and analytical methods
3.2
repeatability limit (r)
the value less than or equal to which the absolute difference between two test results obtained under
repeatability conditions may be expected to be with a probability of 95 %
[SOURCE: ISO 5725-1:1994]
Note 1 to entry: In other words, r is the minimum difference between two results in order to be statistically different,
under repeatability conditions, at a 95 % probability level.
3.3
reproducibility limit (R)
the value less than or equal to which the absolute difference between two test results obtained under
reproducibility conditions may be expected to be with a probability of 95 %
[SOURCE: ISO 5725-1:1994]
Note 1 to entry: In other words, R is the minimum difference between two results in order to be statistically different,
under reproducibility conditions, at a 95 % probability level.
4 Statistical method validation
4.1 General
European laboratories were involved, including as well private, industry, official as commercial laboratories.
ISO 5725-2 was applied as standard for ring testing and statistical evaluation of its results.
In general, legislative tolerances are given to accommodate variability in raw materials, manufacturing,
sampling and analytical routines.
4.2 Approach taken by CEN/TC 260/WG 7
4.2.1 Product selection
The European market is characterised by a broad portfolio of different types of fertilizer grades, Hence there
was a need for selection of a limited number of products to be tested for the ring-test(s). Aim during the
selection process was to get fertilizer samples tested reflecting some main grades sold in the EEC.
4.2.2 Samples and their preparation
In order to be able to evaluate the precision data of the method as such, samples have been taken to the
utmost extent as a spot (not agglomerated) sample out of a bulk production. This was done on purpose as to
reduce the possible variation originating from raw materials, manufacturing and sampling procedure.
Furthermore, all samples have been ground before distribution to the participating labs. Only solid,
homogeneous samples and liquid samples have been used; no blends. The aim was to work with a limited
number of samples, representing the main fertilizer grades applied.
4.2.3 Laboratories involved
The participation of the laboratories was on a voluntary basis, enabling as well private and industry, official
...