Minimum Criteria for Supporting Evidence of Third Party Certification using EN 13501 Classification Series

Third Party Certification: Supporting Evidence

Minimum criteria for Certification and Technical Services based on EN Classification using the EN 13501 series

Introduction

The objective of third party certification schemes is to provide confidence to interested parties that the product can provide the required performance stated by the manufacturer. Third party product certification schemes also allow suppliers to demonstrate to the market that their product has been attested to fulfil specified requirements.

For a third party certification scheme to provide the highest level of assurance, they must include conformity assessment activities that allow the performance of the product to be independently determined, audited and maintained on an ongoing basis. Schemes operating at the highest level, such as those provided by Warringtonfire Testing and Certification Limited (WTCL), are defined as Type 5 certification schemes according to ISO 17067.

This technical information sheet explains the minimum criteria for supporting evidence used within the voluntary third party certification schemes operated by WTCL (Certifire and Q-Mark), trading as Warringtonfire Certification or BM TRADA, for EN classification of construction products using the EN 13501 series. Detail on how the supporting evidence is used for the purpose of certification is given in the relevant BM TRADA scheme technical document or Warringtonfire Certification technical schedule.

The following items are considered as supporting evidence for the purpose of certification. In this document, the minimum criteria for each is explained.

• Sampling
• Initial Type Testing (ITT)
• Direct Field of Application (DIAP)
• Extended Field of Application (EXAP)
• Classification Reports

Note 1: On 2nd September 2024, the UK Government confirmed that the National Classes fire testing standards will be withdrawn from Approved Document B (England) in favour of the EN 13501 series of European classification standards. A transition period of 5 years was given by the UK Government for fire resisting construction products, meaning products such as fire resisting doorsets will need to be classified to EN 13501-2 for the relevant performance characteristics from 2nd September 2029.

Sampling

Sampling acts as a means of providing added assurance that the product being constructed for testing relates to the product that will be placed on the market.

Sampling allows traceability of the test sample, including components, raw materials and purchase orders, back to the facility where it was fabricated, and it also gives information on specific aspects of construction that would only be visible during the manufacturing process.

The process of sampling for testing differs depending on the type of product being sampled. It varies if the product is:

• Being taken ‘off the shelf’ (i.e. a representative market sample)
• Constructed specifically for generating initial test evidence (i.e. prototype)
• Not ‘off the shelf’ (i.e. non-series or made to order)

In all cases, the objective of sampling is the same – to make sure the product being tested relates to that being offered (or due to be offered) for sale and to record information on the production processes and materials used, prior to testing, that may otherwise be hard or impossible to determine once the product is made. This information can be referred to later in the certification cycle to confirm that products are representative of those originally tested.

The sampling requirements for WTCL schemes are detailed below:

• The sampling must have been conducted by a representative of an ISO 17065 accredited certification body and/or a UK Approved Body or EU Notified Body under applicable Construction Product Regulation at the time the sampling was conducted.

• All sampling and sampling reports shall follow the principles of Group of Notified Bodies (GNB) document NB-CPR 15/639r3 (see note 2) and any relevant scheme rules/checklists and must be in English.

• As sampling is a key conformity assessment activity under the responsibility of the Certification Body, it is normally undertaken by the body that is providing the certification. Therefore, the sampling for both Certifire and Q-Mark schemes would be undertaken by WTCL. 

• WTCL may accept sampling for ITT conducted by others (e.g. an approved or notified certification body), subject to the report meeting the criteria outlined herein and following a review and documented approval by WTCL. Please note: For audit testing, including pre-certification testing, the sampling shall be conducted by WTCL.

• Additional WTCL scheme specific sampling requirements are to be met. The requirements can be supplied on request.

• For all new certification applications and all extensions to scope, all test evidence must have been appropriately sampled, in line with the criteria outlined herein.
• We are ensuring that all new certification scopes and schemes only include sampled evidence, in anticipation of the strengthened testing and certification regime for construction products being proposed by UK Government.

Note 2: The Group of Notified Bodies is a co-ordinated group of bodies that provide testing and certification of construction products under the Construction Products Regulation in the E.U. NB-CPR 15/639r3 is an approved position paper on sampling requirements for Notified Certification Bodies issued by the Advisory Group of the GNB-CPR.

Initial Type Testing (ITT)

ITT is a critical aspect of establishing a product’s performance to the relevant test standard and must meet specific requirements to be considered for the purpose of certification by WTCL, based on impartiality, performance and relevance.

The requirements for ITT are given below:

• ITT is required for each Product Type to be incorporated into the scheme, and each performance characteristic that is to be certified.
• The laboratory conducting the test must be United Kingdom Accreditation Service (UKAS) accredited or accredited by an Accreditation Body that is a signatory of ILAC (International Laboratory Accreditation Cooperation) to ISO 17025 for the appropriate test standard, which must have been included in their schedule at the time of the test.
• The test laboratory must have Notified Body/Approved Body status and/or be a member of the European Group of Organisations for Fire Testing, Inspection and Certification (EGOLF). This is to demonstrate test lab independence and impartiality.
• The test laboratory must follow all appropriate EGOLF agreements and position papers for test to the EN suite of test standards. It is preferential, but not essential, that EGOLF recommendations are followed as ‘best practice’. The test lab does not have to be a member of EGOLF to achieve this requirement.
• The test itself must be covered by the accreditation scope of the laboratory. This will usually be indicated by the Accreditation Body logo (e.g. UKAS logo) being printed on the report.
• ITT must be in the English language. ITT not in English must be translated using a legally notarised technical translation service or be reissued in English by the laboratory who originally issued the documents.

If a test laboratory does not meet all the above criteria, the laboratory cannot be used to generate evidence for the purpose of third party certification schemes operated by WTCL, unless it is witnessed according to the Warringtonfire’s witness testing procedure.

Manufacturers should engage with Warringtonfire as early as possible, if they intend to use a laboratory that does not meet the above criteria for the purpose of generating ITT for use within a scheme operated by WTCL. This provides an opportunity for Warringtonfire to explain the witnessing procedure and helps prevent evidence being generated that does not meet WTCL scheme requirements, avoiding unnecessary delays and cost.

WTCL reserves the right not to accept test evidence that meets all the above criteria for another reason not specified in these rules – for example, if there is doubt over the veracity of the results, or the independence or credibility of the laboratory.

Direct Field of Application (DIAP)

A DIAP provides an extension to the scope of the tested design and is based on rules given within standards (e.g. test standards). A DIAP can be used for the purpose of classification; however, it is important that the DIAP is clearly defined in the classification report based on the tested design.

A classification report that only refers to a test report that lists the DIAP rules from the test standard will require interpretation of permissible scope. This alone is insufficient for the purpose of certification as there may be differing interpretations between end users (e.g. manufacturer, certification body, regulators) regarding the extent of permissible variations from the tested design.

The requirements for DIAP are given below:

• All DIAP scope for the tested product shall be clearly defined in the classification report.
• The interpretation of the permissible extent of DIAP scope is based on the rules given in the relevant standard and shall be defined by the test laboratory that has prepared the classification report.
• All test evidence on which the permissible extent of DIAP scope is based, irrespective of age, will require a declaration from the manufacturer that “no alteration of components or construction has been made to the product” since that test evidence was created.
• WTCL policy is to follow Annex D of the PFPF Guide to undertaking technical assessments of fire performance of construction products based on fire test evidence (2021) for all evidence reviews, where that evidence is used to formulate a scope of application (e.g. DIAP).
• At least one piece of evidence must have met the intended performance to be classified. The evidence must be directly relevant to the product being classified (i.e. not supporting evidence).
• Historic test evidence (i.e. evidence generated to an earlier version of the standard than that stated in the scheme document) may be considered. It is WTCL’s policy to follow the applicable GNB guidance on the use of historic evidence, NB-CPR/19/792r5 or NB-CPR/SH02/SG06-18/001r1, as applicable.
• Test evidence on which the permissible extent of DIAP scope is based must be in the English language.
• Evidence not in English must be translated using a legally notarised technical translation service or be reissued in English by the laboratory who originally issued the documents.
• We require written permission for each use of, and reference to, test evidence on which the permissible extent of DIAP scope is based, where the test evidence is not the property of the customer that has contracted the work with us.

Extended Field of Application (EXAP)

An EXAP provides an extension to scope of the tested design and is based on rules given within relevant EXAP standards (e.g. EN 15269 series). EXAPs are often based on more than one test report and provide a wider scope of application than a classification report based on extension by DIAP.

For certification, it is important that the relevant EXAP reports are clearly referenced in the classification report based on the test evidence, and that the scope of EXAP is clearly linked to the associated classification.

The EXAP document provides the field of application for the products that the manufacturer wants to provide to market under third party certification. Despite being primarily a rule-based system, the interpretation and application of EXAP rules can vary greatly between laboratories, which can lead to a wide variation in the products that are supported between different EXAP reports.

Given that EXAPs support the performance of products that have not been directly tested and are based on interpretation and application of multiple rules, WTCL has made the decision to only accept EXAPs that have been prepared within its own organisation for products to be certified under a scheme operated by WTCL. 

This not only helps to provide consistency to the field of application of products that are certified under the schemes operated by WTCL, but also offers the certification body tighter control over any changes or withdrawals of scope that may be required in response to audit testing or inspection of factory production control.

The requirements for EXAP are given below:

• For the product to be certified, WTCL will only accept EXAPs that have been prepared within their own organisation, and subject to the sampling and supporting evidence meeting the requirements outlined herein.
• EN 15725 states that EXAP should be undertaken by an organisation accredited for the relevant test according to EN ISO/IEC 17025 that has also carried out at least one test on the product being considered for the EXAP. WTCL may prepare EXAPs for use inside certification where all evidence has been generated at another laboratory on the basis that the product will be subject to pre-certification and/or ongoing audit testing and the EXAP will be prepared by a product assessor with the appropriate competence in the field of testing and classifying similar construction products.
• All EXAP reports relevant to the product’s classification shall be clearly referenced in the classification report.
• All test evidence on which the permissible extent of EXAP scope is based, irrespective of age, will require a declaration from the manufacturer that “no alteration of components or construction has been made to the product” since that test evidence was created.
• WTCL policy is to follow Annex D of the PFPF Guide to undertaking technical assessments of fire performance of construction products based on fire test evidence (2021) for all evidence reviews, where that evidence is used to formulate a scope of application (e.g. EXAP).
• At least one piece of evidence must have met the intended performance to be classified. The evidence must be directly relevant to the product being classified (i.e. not supporting evidence).
• Historic test evidence (i.e. evidence generated to an earlier version of the standard than that stated in the scheme document) may be considered. It is WTCL’s policy to follow the applicable GNB guidance, NB-CPR/19/792r5 or NB-CPR/SH02/SG06-18/001r1, as applicable.
• Test evidence on which the permissible extent of EXAP scope is based must be in the English language. Evidence not in English must be translated using a legally notarised technical translation service or be reissued in English by the laboratory who originally issued the documents. This also applies to any EXAPs prepared by other laboratories that are to be reviewed by Warringtonfire for the purpose of certification under WTCL.
• We require written permission for each use of, and reference to, test evidence on which the permissible extent of EXAP scope is based, where the test evidence is not the property of the customer that has contracted the work with us.

Classification Report

A classification report confirms the classified performance assigned to the construction product and either contains the permissible extent of DIAP scope for the classified product or references the EXAP on which the classification is based.

Classification reports for construction products are written in accordance with the EN 13501 series depending on the type of product and performance (e.g. reaction to fire, resistance to fire) and are normally prepared by the laboratory that conducted the testing and DIAP/EXAP reports on which the classification is based. WTCL may prepare classification reports for use inside certification where all evidence has been generated at another laboratory on the basis that the product will be subject to pre-certification and/or ongoing audit testing and the classification report will be prepared by a product assessor with the appropriate competence in the field of testing and classifying similar construction products.

Note 3: UKAS recommends that classification reports issued using EN 13501 series are under ISO 17025 accreditation. This is further supported by the Group of Notified Bodies’ recommendation item 306 on GNB-CPR Guidance Base.

The requirements for classification reports are given below:

• The permissible extent of scope based on DIAP must be contained within the classification report, clearly defining the scope of the tested designs.
• When a classification report is based on EXAP, it must reference the EXAP report. This is to enable the scope of designs given in the separate EXAP report to be linked to the assigned classified performance characteristics in the classification report.
• All classification reports for products certified under the schemes operated by WTCL shall be written by Warringtonfire. However, it is possible to use test evidence that has been prepared by laboratories other than Warringtonfire, subject to review and verification that the reports meet the requirements of WTCL outlined herein.

Revisions

• Version 2, published on 5th November 2025: Updated to provide clarification on sampling requirements when using other certification bodies and for existing scopes of certification.
• Version 3, published 1st May 2026: Updated to provide (1) clarification on sampling requirements for test evidence for all new certification, applications and extensions to scope, (2) an update to WTCL's position on acceptance of EXAPs written by other organisations, and (3) justification of preparing EXAPs and classification reports where WTCL have not conducted at least one of the tests.

Note: The last revised version of this document supersedes all previous versions/revisions.