FprEN IEC 60695-5-2:2026
(Main)Fire hazard testing - Part 5-2: Corrosion damage effects of fire effluent - Summary and relevance of test methods
- Status
- Not Published
- Publication Date
- 29-Oct-2026
- Technical Committee
- CLC/SR 89 - Fire hazard testing
- Current Stage
- 5060 - Voting results sent to TC, SR - Formal Approval
- Start Date
- 04-Sep-2026
- Completion Date
- 04-Sep-2026
FprEN IEC 60695-5-2:2026 is a fire hazard testing document from IEC/CLC that summarizes test methods used to assess the corrosivity of fire effluent. It explains how the methods relate to electrotechnical products, their materials, and fire scenarios, and it helps product committees judge which method is suitable for a given use. The document is about comparing methods and understanding their relevance, not about giving a single universal corrosion test.
What does FprEN IEC 60695-5-2:2026 specify?
FprEN IEC 60695-5-2:2026 specifies a summary of test methods used to assess the corrosivity of fire effluent, together with notes on how relevant those methods are to real fire scenarios. It covers methods in common use as international, national, or industry standards and gives recommendations for their use.
The document is organized into clauses on scope, references, terms, classification of methods, published test methods, and an overview of method relevance. It also includes two informative annexes that support comparison of aqueous-solution methods and repeatability/reproducibility data.
| Annex | What it covers |
|---|---|
| Annex A | Differences between acidity and conductivity test methods for aqueous solutions obtained after bubbling combustion effluent through water |
| Annex B | Comparative tests used to examine repeatability and reproducibility for solutions of combustion gases |
What are the key requirements of FprEN IEC 60695-5-2:2026?
FprEN IEC 60695-5-2:2026 is mainly a guidance and comparison document, but it still makes several practical points that affect method selection and interpretation. The most important rule is that product committees shall choose a test that suits the intended use, and they shall not use these methods as a direct description of actual fire risk under real fire conditions.
Clause 4 - classify the method before using it
FprEN IEC 60695-5-2:2026 classifies methods by the nature of the test specimen, the physical fire model, and the way corrosivity is measured. In practice, that means the same material can give different results depending on whether you test a product, a material sample, or a simulated target.
Clause 4 also distinguishes product testing from material or composite sample testing. This matters because a finished product, such as a printed circuit board or switchboard, can behave differently from the same material tested as a small specimen.
Clause 4.3 - make the fire model relevant to the fire stage
FprEN IEC 60695-5-2:2026 stresses that test conditions must represent the desired stage of a real fire. The document points to oxygen concentration, irradiance, and temperature as the main variables that shape the fire effluent.
For a user, this means the choice of heat source and ventilation is not a detail - it changes what corrosive species are produced and therefore changes the ranking of materials.
Clause 4.4 - choose the right way to measure corrosivity
FprEN IEC 60695-5-2:2026 describes three broad measurement approaches: a product as the target, a simulated product as the target, or an indirect assessment of gases and vapours. Direct targets look at damage on the product or a reference target, while indirect methods look at the chemistry of the effluent.
In practice, direct methods are better when you need to see metal loss or function loss on a target. Indirect methods are easier to run, but they need a known link to actual corrosion damage before the result can be used as a corrosion indicator.
Clause 5.2 - halogen acid in combustion gases
FprEN IEC 60695-5-2:2026 says the halogen acid method is an analytical chemistry test for cable materials. It measures halogen acid gas evolved during combustion, but it does not directly measure corrosion damage.
This matters because a high result suggests corrosive potential, but a low result does not prove low corrosivity. The document also notes that the combustion conditions are set to maximize halogen acid production and are closest to non-flaming pyrolytic decomposition.
Clause 5.3 - acidity and conductivity of combustion gases dissolved in water
FprEN IEC 60695-5-2:2026 presents methods that bubble fire effluent through water and then measure pH, or pH and conductivity. These methods can rank similar materials for corrosive potential, but only if the correlation to actual corrosivity has been established for the scenario of interest.
The practical point is that this is a useful screening approach, especially for comparing materials within the same family. It is not enough on its own to predict corrosion damage in every fire scenario.
Clause 5.4 and 5.5 - target-based methods for copper and metal loss
FprEN IEC 60695-5-2:2026 also summarizes target-based methods based on copper corrosion and the cone corrosimeter. These methods evaluate corrosion damage by observing copper attack or by measuring metal loss from a target after exposure to combustion products.
The cone corrosimeter method uses an active target and a reference element and calculates metal loss from the change in electrical resistance. That makes it useful when the question is how much metal loss a material or product may cause under controlled conditions, especially in design and development work.
Clause 6 - use the methods as part of a wider assessment
FprEN IEC 60695-5-2:2026 says the methods evaluate relative corrosion damage under controlled laboratory conditions and should not be used to describe or appraise corrosion risk under actual fire conditions. It also says corrosion ranking should be combined with heat and flame response data such as ignitability, surface spread of flame, and rate of heat release.
For a buyer, engineer, or quality manager, this means the document supports comparison and selection, not a standalone pass/fail judgment on real-world fire risk.
What terms does FprEN IEC 60695-5-2:2026 define?
- corrosion damage - physical or chemical damage, or impaired function, caused by chemical action.
- corrosion target - the sensor or target used to determine the degree of corrosion damage under specified test conditions.
- fire effluent - the gases and aerosols, including suspended particles, created by combustion or pyrolysis and emitted to the environment.
- fire scenario - a qualitative description of how a fire develops over time, including the key events that define it.
- physical fire model - the laboratory apparatus, environment, and procedure used to represent a phase of a fire.
- pyrolysis - chemical decomposition of a substance by heat.
- smoke - the visible part of fire effluent.
Who uses FprEN IEC 60695-5-2:2026?
FprEN IEC 60695-5-2:2026 is aimed at IEC and product committees that need to choose or judge corrosion-related fire tests for electrotechnical products. It is also useful to engineers, test laboratories, and materials specialists working on cables, printed circuit boards, switchboards, computers, heat-shrinkable tubing, insulations, and covering products.
Quality managers and buyers can use it to understand what a reported test result really means. The document is especially relevant where corrosion damage could affect safety-related or high-value equipment.
Which standards are used with FprEN IEC 60695-5-2:2026?
FprEN IEC 60695-5-2:2026 is read together with several standards that provide terminology, general guidance, or the detailed test methods it summarizes.
- IEC 60695-4 - provides terminology for fire tests.
- IEC 60695-5-1 - gives the general guidance and field of application for corrosion damage effects of fire effluent.
- ISO 13943:2017 - provides fire safety vocabulary used for key terms in the document.
- IEC 60695-1-10, IEC 60695-1-11, IEC 60695-1-12 - provide general guidance on assessing the fire hazard of electrotechnical products, fire hazard assessment, and fire safety engineering.
- IEC 60754-1 - underlies the halogen acid gas method for cable materials.
- IEC 60754-2 - underlies the acidity and conductivity method for gases dissolved in water.
- CAN/CSA C22.2 No. 0.3, DIN VDE 0472 Part 813, NF C20-453 - national methods based on the same aqueous-solution approach.
- ASTM D 2671 sections 89 to 95 - provides the copper corrosion procedures summarized in Clause 5.4.
- ISO 11907-4 and ASTM D 5485 - provide the cone corrosimeter methods summarized in Clause 5.5.
What does the FprEN IEC 60695-5-2:2026 document contain?
FprEN IEC 60695-5-2:2026 contains a classification of corrosivity test methods, summaries of published methods, and guidance on when each method is relevant. It also contains Table 1 on fire stages, which helps link laboratory conditions to fire behavior, and Table 2, which compares the methods by specimen type, limitations, and relevance to fire stages.
Figure 1 shows a typical corrosion target with active and reference elements. Annex A compares aqueous-solution methods, and Annex B gives comparative pH and resistivity data used to discuss repeatability and reproducibility.
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Frequently Asked Questions
FprEN IEC 60695-5-2:2026 is a draft published by CLC. Its full title is "Fire hazard testing - Part 5-2: Corrosion damage effects of fire effluent - Summary and relevance of test methods". This standard covers: Fire hazard testing - Part 5-2: Corrosion damage effects of fire effluent - Summary and relevance of test methods
Fire hazard testing - Part 5-2: Corrosion damage effects of fire effluent - Summary and relevance of test methods
FprEN IEC 60695-5-2:2026 is classified under the following ICS (International Classification for Standards) categories: 13.220.99 - Other standards related to protection against fire; 19.020 - Test conditions and procedures in general; 29.020 - Electrical engineering in general. The ICS classification helps identify the subject area and facilitates finding related standards.
FprEN IEC 60695-5-2:2026 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 IEC 60695-5-2:2026
01-marec-2026
Preskušanje požarne ogroženosti - 5-2. del: Poškodbe zaradi korozijskega učinka
izžarevanja ognja - Povzetek in relevantnost preskusnih metod
Fire hazard testing - Part 5-2: Corrosion damage effects of fire effluent - Summary and
relevance of test methods
Ta slovenski standard je istoveten z: prEN IEC 60695-5-2:2026
ICS:
13.220.99 Drugi standardi v zvezi z Other standards related to
varstvom pred požarom protection against fire
19.020 Preskuševalni pogoji in Test conditions and
postopki na splošno procedures in general
29.020 Elektrotehnika na splošno Electrical engineering in
general
oSIST prEN IEC 60695-5-2:2026 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN IEC 60695-5-2:2026
oSIST prEN IEC 60695-5-2:2026
89/1641/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60695-5-2 ED2
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2026-01-16 2026-04-10
SUPERSEDES DOCUMENTS:
89/1614/CD, 89/1638/CC
IEC TC 89 : FIRE HAZARD TESTING
SECRETARIAT: SECRETARY:
Germany Mr Bernd Komanschek
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):
TC 10,TC 14,TC 20,SC 22F,SC 23A,TC 46,TC 61,SC
86A,TC 99,TC 104,TC 112,SC 121A,ACOS
ASPECTS CONCERNED:
Safety
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of
which they are aware and to provide supporting documentation.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is the
final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).
TITLE:
Fire hazard testing - Part 5-2: Corrosion damage effects of fire effluent - Summary and relevance
of test methods
PROPOSED STABILITY DATE: 2029
NOTE FROM TC/SC OFFICERS:
this electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee
positions. You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other
purpose without permission in writing from IEC.
oSIST prEN IEC 60695-5-2:2026
IEC CDV 60695-5-2 © IEC 2025
1 CONTENTS
2 FOREWORD . 4
3 INTRODUCTION . 6
4 1 Scope . 7
5 2 Normative references . 7
6 3 Terms and definitions . 7
7 4 Classification of test methods . 8
8 4.1 General . 8
9 4.2 Test specimen . 8
10 4.2.1 Product testing . 8
11 4.2.2 Material or composite sample testing . 8
12 4.3 The physical fire model . 8
13 4.4 The nature of the corrosivity measurement . 9
14 4.4.1 Product as target . 9
15 4.4.2 Simulated product as target . 9
16 4.4.3 Indirect assessment . 11
17 5 Published test methods . 11
18 5.1 General . 11
19 5.2 Tests for the determination of halogen acid in combustion gases . 11
20 5.2.1 Standards . 11
21 5.2.2 Purpose and principle . 11
22 5.2.3 Test specimen . 11
23 5.2.4 Test method . 11
24 5.2.5 Repeatability and reproducibility . 11
25 5.2.6 Relevance of test data to corrosion hazard assessment . 11
26 5.3 Tests for the determination of the acidity and conductivity of combustion
27 gases dissolved in an aqueous solution . 12
28 5.3.1 Standards . 12
29 5.3.2 Purpose and principle . 12
30 5.3.3 Test specimen . 12
31 5.3.4 Test method . 12
32 5.3.5 Repeatability and reproducibility . 12
33 5.3.6 Relevance of test data to corrosion hazard assessment . 12
34 5.4 Tests for the determination of corrosive gases by evaluation of copper
35 corrosion in ASTM D 2671 – Sections 89 to 95 [9] . 13
36 5.4.1 Purpose and principle . 13
37 5.4.2 Test specimen . 13
38 5.4.3 Test methods . 13
39 5.4.4 Special observations . 13
40 5.4.5 Repeatability and reproducibility . 13
41 5.4.6 Relevance of test data to corrosion hazard assessment . 13
42 5.5 Cone corrosimeter method . 13
43 5.5.1 Standards . 13
44 5.5.2 Purpose and principle . 13
45 5.5.3 Test specimen . 14
46 5.5.4 Corrosion target . 14
47 5.5.5 Test method . 14
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48 5.5.6 Special observation . 15
49 5.5.7 Repeatability and reproducibility . 15
50 5.5.8 Relevance of test data to corrosion hazard assessment . 15
51 6 Overview of methods and relevance of data . 15
52 Annex A (informative) Acidity and conductivity of aqueous solutions – Test methods . 18
53 Annex B (informative) Determination of repeatability and reproducibility –
54 Comparative tests of solutions of combustion gases . 19
55 Bibliography . 23
57 Figure 1 – Schematic drawing of a typical corrosion target of defined metal thickness …….15
59 Table 1 – Characteristics of fire stages (from Table 1 in ISO 19706:2011) . 10
60 Table 2 – Overview of corrosivity test methods . 17
61 Table A.1 – Test methods for the measurement of acidity and conductivity of aqueous
62 solutions obtained after bubbling combustion effluent through water . 18
63 Table B.1 – Determination of repeatability and reproducibility – Comparative pH tests
64 on solutions of combustion gases . 20
65 Table B.2 – Determination of repeatability and reproducibility – Comparative resistivity
66 tests on solutions of combustion gases . 20
67 Table B.3 – Results obtained on brominated polycarbonate . 22
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70 INTERNATIONAL ELECTROTECHNICAL COMMISSION
71 ____________
73 FIRE HAZARD TESTING –
75 Part 5-2: Corrosion damage effects of fire effluent –
76 Summary and relevance of test methods
78 FOREWORD
79 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
80 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
81 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
82 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
83 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
84 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
85 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
86 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
87 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
88 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
89 consensus of opinion on the relevant subjects since each technical committee has representation from all
90 interested IEC National Committees.
91 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
92 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
93 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
94 misinterpretation by any end user.
95 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
96 transparently to the maximum extent possible in their national and regional publications. Any divergence between
97 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
98 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
99 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
100 services carried out by independent certification bodies.
101 6) All users should ensure that they have the latest edition of this publication.
102 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
103 members of its technical committees and IEC National Committees for any personal injury, property damage or
104 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
105 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
106 Publications.
107 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
108 indispensable for the correct application of this publication.
109 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
110 rights. IEC shall not be held responsible for identifying any or all such patent rights.
111 International Standard IEC 60695-5-2 has been prepared by IEC technical committee 89: Fire
112 hazard testing.
113 It has the status of a basic safety publication in accordance with IEC Guide 104 and
114 ISO/IEC Guide 51.
115 The text of this International Standard is based on the following documents:
FDIS Report on voting
89/XXXX/FDIS 89/YYYY/RVD
117 Full information on the voting for its approval can be found in the report on voting indicated in
118 the above table.
119 This document was drafted in accordance with ISO/IEC Directives, Part 2.
120 This International Standard is to be read in conjunction with IEC 60695-5-1.
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IEC CDV 60695-5-2 © IEC 2025
121 A list of all parts in the IEC 60695 series, published under the general title Fire hazard testing,
122 can be found on the IEC website.
123 IEC 60695-5 consists of the following parts:
124 Part 5-1: Corrosion damage effects of fire effluent - General guidance
125 Part 5-2: Corrosion damage effects of fire effluent – Summary and relevance of test methods
126 The committee has decided that the contents of this document will remain unchanged until the
127 stability date indicated on the IEC website under webstore.iec.ch in the data related to the
128 specific document. At this date, the document will be
129 • reconfirmed,
130 • withdrawn,
131 • replaced by a revised edition, or
132 • amended.
133 The National Committees are requested to note that for this document the stability date is 2029.
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135 INTRODUCTION
136 In the design of an electrotechnical product the risk of fire and the potential hazards associated
137 with fire need to be considered. In this respect the objective of component, circuit and
138 equipment design, as well as the choice of materials, is to reduce the risk of fire to a tolerable
139 level even in the event of reasonably foreseeable (mis)use, malfunction or failure.
140 IEC 60695-1-10 [1] , IEC 60695-1-11 [2], and IEC 60695-1-12 [3] provide guidance on how this
141 is to be accomplished.
142 Fires involving electrotechnical products can also be initiated from external non -electrical
143 sources. Considerations of this nature are dealt with in an overall fire hazard assessment.
144 The aim of the IEC 60695 series is to save lives and property by reducing the number of fires
145 or reducing the consequences of the fire. This can be accomplished by:
146 • trying to prevent ignition caused by an electrically energised component part and, in the
147 event of ignition, to confine any resulting fire within the bounds of the enclosure of the
148 electrotechnical product.
149 • trying to minimise flame spread beyond the product’s enclosure and to minimise the harmful
150 effects of fire effluents including heat, smoke, and toxic or corrosive combustion products.
151 All fire effluent is corrosive to some degree and the level of potential to corrode depends on the
152 nature of the fire, the combination of combustible materials involved in the fire, the nature of
153 the substrate under attack, and the temperature and relative humidity of the environment in
154 which the corrosion is taking place. There is no evidence that fire effluent from electrotechnical
155 products offers greater risk of corrosion damage than the fire effluent from other products such
156 as furnishings, building materials, etc.
157 The performance of electrical and electronic components can be adversely affected by
158 corrosion damage when subjected to fire effluent. A wide variety of combinations of small
159 quantities of effluent gases, smoke particles, moisture and temperature may provide conditions
160 for electrical component or system failures from breakage, overheating or shorting.
161 Evaluation of potential corrosion damage is particularly important for high value and safety-
162 related electrotechnical products and installations.
163 Technical committees responsible for the products will choose the test(s) and specify the level
164 of severity.
165 The study of corrosion damage requires an interdisciplinary approach involving chemistry,
166 electricity, physics, mechanical engineering, metallurgy and electrochemistry. In the
167 preparation of this part of IEC 60695, all of the above have been considered.
168 IEC 60695-5-1 defines the scope of the guidance and indicates the field of application.
169 IEC 60695-5-2 provides a summary of test methods including relevance and usefulness.
Numbers in square brackets refer to the bibliography.
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172 FIRE HAZARD TESTING –
174 Part 5-2: Corrosion damage effects of fire effluent –
175 Summary and relevance of test methods
179 1 Scope
180 This part of IEC 60695 summarises the test methods that are used in the assessment of the
181 corrosivity of fire effluent. It presents a brief summary of test methods in common use, either
182 as international standards, national or industry standards. It includes special observations on
183 their relevance, for electrotechnical products and their materials, to real fire scenarios and gives
184 recommendations on their use.
185 2 Normative references
186 The following documents are referred to in the text in such a way that some or all of their content
187 constitutes requirements of this document. For dated references, only the edition cited applies.
188 For undated references, the latest edition of the referenced document (including any
189 amendments) applies.
190 IEC 60695-4, Fire hazard testing – Part 4: Terminology concerning fire tests
191 IEC 60695-5-1, Fire hazard testing – Part 5-1: Corrosion damage effects of fire effluent -
192 General guidance
193 ISO 13943:2017, Fire safety – Vocabulary
194 3 Terms and definitions
195 For the purposes of this document, the terms and definitions given in IEC 60695-4 and
196 ISO 13943:2017 (some of which are reproduced below) apply.
197 3.1
198 corrosion damage
199 physical and/or chemical damage or impaired function caused by chemical action
200 [SOURCE: ISO 13943:2017, 3.69]
201 3.2
202 corrosion target
203 sensor used to determine the degree of corrosion damage (3.1), under specified test conditions
204 Note 1 to entry: This sensor may be a product, a component. It may also be a reference material or object used to
205 simulate the behaviour of a product or a component.
206 [SOURCE: ISO 13943:2017, 3.70]
207 3.3
208 fire effluent
209 all gases and aerosols, including suspended particles created by combustion or pyrolysis (3.6)
210 and emitted to the environment
211 [SOURCE: ISO 13943:2017, 3.123]
212 3.4
213 fire scenario
214 qualitative description of the course of a fire with respect to time, identifying key events that
215 characterize the studied fire and differentiate it from other possible fires
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216 Note 1 to entry: See fire scenario cluster (ISO 13943:2017, 3.154) and representative fire scenario
217 (ISO 13943:2017, 3.153).
218 Note to entry: It typically defines the ignition and fire growth processes, the fully developed fire stage, the fire decay
219 stage, and the environment and systems that will impact on the course of the fire.
220 Note to entry: Unlike deterministic fire analysis, where fire scenarios are individually selected and used as design
221 fire scenarios, in fire risk assessment, fire scenarios are used as representative fire scenarios within fire scenario
222 clusters.
223 [SOURCE: ISO 13943:2017, 3.152]
224 3.5
225 physical fire model
226 laboratory process, including the apparatus, the environment and the fire test procedure
227 intended to represent a certain phase of a fire
228 [SOURCE: ISO 13943:2017, 3.298]
229 3.6
230 pyrolysis
231 chemical decomposition of a substance by the action of heat
232 Note 1 to entry: Pyrolysis is often used to refer to a stage of fire before flaming combustion has begun.
233 Note 2 to entry: In fire science, no assumption is made about the presence or absence of oxygen.
234 [SOURCE: ISO 13943:2017, 3.316]
235 3.7
236 smoke
237 visible part of a fire effluent (3.3)
238 [SOURCE: ISO 13943:2017, 3.347]
239 4 Classification of test methods
240 4.1 General
241 The test methods included in this document can generally be classified according to the
242 following three criteria:
243 a) the nature of the test specimen which is burnt;
244 b) the physical fire model used in the test;
245 c) the nature of the measurement of corrosivity.
246 4.2 Test specimen
247 4.2.1 Product testing
248 The test specimen is a manufactured product or a representative portion of a product. Examples
249 include a printed circuit board, a switchboard, a computer or a cable.
250 4.2.2 Material or composite sample testing
251 The test specimen is a basic material (solid or liquid), or composite of materials.
252 4.3 The physical fire model
253 Test methods use a wide variety of heat sources and geometries. The amount, the rate of
254 production and the corrosive nature of fire effluent released from a given material or product is
255 not an inherent property of that material or product, but is critically dependent on the conditions
256 under which that material or product is burnt. In a fire scenario or a fire test, the chemical nature
257 of the fuel, the decomposition temperature and the amount of ventilation are the main variables
258 which affect the composition of fire effluent.
259 It is critical to show that the test conditions defined in a standardized test method are relevant
260 to, and replicate, the desired stage of a real fire. ISO has published a general classification of
261 fire stages in ISO 19706:2011, shown in Table 1. The important factors affecting effluent
262 production are oxygen concentration, irradiance and temperature.
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263 4.4 The nature of the corrosivity measurement
264 4.4.1 Product as target
265 The corrosion target is a manufactured product or a representative portion of a product, which
266 can be represented by a test specimen. Examples include: printed wiring boards, switchboards,
267 washing machines and computers.
268 The corrosion damage effects of fire effluent on the product can be assessed by degradation of
269 function as determined by inspection or measurement.
270 4.4.2 Simulated product as target
271 When a simulated product is used as the target, the corrosion target is typically a reference
272 circuit, a thin sheet of metal or a metal mirror. The corrosion damage effects of fire effluent on
273 the target can be assessed by changes in appearance, mass or measurements of mechanical,
274 physical or electrical characteristics.
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275 Table 1 – Characteristics of fire stages (from Table 1 in ISO 19706:2011)
Max. temperature Oxygen volume
Heat flux to
100[CO ]
[CO] 2
Fuel/air
fuel surface
C %
Fire stage equivalence [CO2]
[CO2]+[CO]
ratio (plume)
v/v
kW/m Fuel surface Upper layer Entrained Exhausted
% efficiency
1 Non-flaming
a self-sustaining not
d
450 to 800 25 to 85 20 20 – 0,1 to 1 50 to 90
(smouldering) applicable
b oxidative pyrolysis
a
b c c
from externally applied – 300 to 600 20 20 1
radiation
c anaerobic pyrolysis
b c c
from externally applied – 100 to 500 0 0 1
radiation
d e
2 Well-ventilated flaming 0 to 60 350 to 650 50 to 500 20 20 1 0,05 95
f
3 Underventilated flaming
a small, localized fire,
generally in a poorly
a
0 to 30 300 to 600 50 to 500 15 to 20 5 to 10 1 0,2 to 0,4 70 to 80
ventilated
compartment
g h i
b post-flashover fire 50 to 150 350 to 650 600 15 5 1 0,1 to 0,4 70 to 90
a
The upper limit is lower than for well-ventilated flaming combustion of a given combustible.
b
The temperature in the upper layer of the fire room is most likely determined by the source of the externally applied radiati on and room geometry.
c
There are few data, but for pyrolysis this ratio is expected to vary widely depending on the material chemistry and the local ventilation and thermal conditions.
d
The fire’s oxygen consumption is small compared to that in the room or the inflow, the flame tip is below the hot gas upper l ayer or the upper layer is not yet significantly
vitiated to increase the CO yield significantly, the flames are not truncated by contact with another object, and the burning rate is controlled by the availability of fuel.
e
The ratio can be up to an order of magnitude higher for materials that are fire-resistant. There is no significant increase in this ratio for equivalence ratios up to 0,75, and
between 0,75 and 1, some increase in this ratio may occur.
f
The fire’s oxygen
...



