FAQ
FAQ on Smoke & Acidity
1. Acidity is a measure of corrosive potency of gasses. Why does EC use Acidity to regulate on Fire Hazard on Humans?
  Acidity is used since years in Fire Regulations of some of the European Member States1 and in the “de facto” Regulations of some European Companies handling Public Services2; that is enough to oblige the EC to include it into the Euroclassification. Moreover has been recognized to be a valid regulatory parameter because:

a. Acidity3 is an easy test method used since years in cable industry to discriminate cables emitting corrosive gasses
b. the field of application of the European Classification is limited to cables used in construction; for these cables - clearly defined by installation standards – this test method is valid
c. sound scientific studies4 demonstrate that cables which fail acidity class a1, emit gasses that reach in few seconds the incapacitation threshold (0.3 FEC5 and/or 0.3 FED6 as per ISO 135717)

(1) Fire Regulations
Italy – Decree of the Ministry of Interior, January the 11th, 1988
France
Slovakia - 94. Vyhláška Ministerstva vnútra Slovenskej republiky, ktorou sa stanovujú technické požiadavky napožiarnu bezpečnosť pri výstavbe a užívaní stavieb - Príloha č. 14 k vyhláške č. 94/2004 Z.z. (94th Notification of Ministry of Interior which defines technical requirementsfor fire security in construction and using of buildings - Attachment nr.14 to notification n. 94/2004 Z.z)
Spain

(2) DeFacto Regulations
France – RATP; UK – London Underground, Heathrow Airport; Italy – Ferrovie dello Stato (Italian Railways)
Belgium - Belgian underground AED CSC 1203

(3) measured according EN50267-2-3 or IEC60754-2

(4) Measurement of the toxicity of gaseous effluents durino Full Scale Test prEN 50399-2-1/2 using Infrared Fourier Transform Technique - V9f/r – March 2005 – LSF presented to ISO/TC92 SC3 WG1 Fire models, Belfast, April 2005

(5) fractional effective concentration, FEC - ratio of the concentration of an irritant to that expected to produce a given effect on an exposed subject of average susceptibility. NOTE 1 As a concept, FEC may refer to any effect, including incapacitation, lethality or even other endpoints. NOTE 2 When not used with reference to a specific irritant, the term FEC represents the summation of FECs for all irritants in a combustion atmosphere. – IEC 60695-7-1

(6) fractional effective dose, FED - ratio of the exposure dose for an asphyxiant toxicant to that expected to produce a given effect on an exposed subject of average susceptibility. NOTE 1 As a concept, FED may refer to any effect, including incapacitation, lethality or even other endpoints. NOTE 2 When not used with reference to a specific asphyxiant, the term FED represents the summation of FEDs for all asphyxiants in a combustion atmosphere. – IEC 60695-7-1

(7) ISO 13571 : 2007 Life-threatening components of fire - Guidelines for the estimation of time available for escape using fire data; ISO 13571:2007 provides guidance on establishing the procedures to evaluate the life threat components of fire hazard analysis in terms of the status of exposed human subjects at discrete time intervals. It makes possible the determination of a tenability endpoint, at which time it is

2. Does Acidity discriminate all the cables emitting hazardous gasses?
  No, there are cables that emit in case of fire hazardous gasses which are not acid. ISO 13571 : 20071 gives the needed distinction of hazardous gases between asphyxiants2 - and irritants gases. Acidity is a measure for irritant gases which are influencing the escape time.

(1) ISO 13571 : 2007 Life-threatening components of fire -- Guidelines for the estimation of time available for escape using fire data; ISO 13571:2007 provides guidance on establishing the procedures to evaluate the life threat components of fire hazard analysis in terms of the status of exposed human subjects at discrete time intervals. It makes possible the determination of a tenability endpoint, at which time it is estimated that occupants are no longer able to take effective action to accomplish their own escape. The life threat components addressed include fire-effluent toxicity, heat and visual obscuration due to smoke.

(2) Asphyxiant - toxicant causing loss of consciousness and ultimately death resulting from hypoxic effects, particularly on the central nervous and/or cardiovascular systems IEC 60695-7-1

3. Halogenated cables start burning at higher temperature than Low fire hazard cables thus avoiding burning and toxic effluents in that temperature range.
 

This phenomena is true (especially for fluorinated cables), but only for smouldering fires1 . In the stage of burning below 500°C the main hazards are smoke and toxic effluents by decomposition, resulting to a drastic decrease of the escape time.

(1) IEC 60695-7-1/ Table 2 – General classification of fire stages in accordance with ISO/TR 9122-1, Smoldering is a slow, lowtemperature, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a condensed phase fuel. – SFPE Handbook of Fire Protection Engineering, 3rd edition, Chapter 2-9


4. Casualties are caused more by CO2 than by HCl ( CO2 is the major cause of death )
  CO2 inhalation is the primary cause of most fire deaths1 The priority it is to allow escape to avoid exposure to CO2; consequently inability to escape due to lack of visibility or the presence of hazardous gases like acid gases which affect the eyes and the pulmonary system are essential.

(1) NIST (US) Special Publication 827 “Toxic Potency Measurement for Fire Hazard Analysis”, December 1991
5. Small quantities of HCl make you aware of the fire
  This is true that the irritating smell of HCl makes you aware of the fire. Unfortunately, the HCl irritating effect starts at very low concentrations and is not possible to limit the emission to “small quantities”. Many other elements of the building can also be the source of HCl or other irritating gases emission in case of fire.
6. Why adopting ISO 13571 to define hazardous effects of effluents in case of fire?
  ISO 13571 became a standard in June 2007 well recognized and approved also by IEC (it is referred in IEC 60695-7-1) as the fundamental standard is this respect. This standard also includes the measure of incapacitation1 threshold taking into account the asphyxiant gases as well as the irritant gases (0.3 FEC2 and/or 0.3 FED3).

(1) Incapacitation - state of physical inability to accomplish a specific task, for example, the inability to take effective action to escape from a fire. – IEC 60695-7-1

(2) fractional effective concentration, FEC - ratio of the concentration of an irritant to that expected to produce a given effect on an exposed subject of average susceptibility. NOTE 1 As a concept, FEC may refer to any effect, including incapacitation, lethality or even other endpoints. NOTE 2 When not used with reference to a specific irritant, the term FEC represents the summation of FECs for all irritants in a combustion atmosphere. – IEC 89/650/FDIS

(3) fractional effective dose, FED - ratio of the exposure dose for an asphyxiant toxicant to that expected to produce a given effect on an exposed subject of average susceptibility. NOTE 1 As a concept, FED may refer to any effect, including incapacitation, lethality or even other endpoints. NOTE 2 When not used with reference to a specific asphyxiant, the term FED represents the summation of FEDs for all asphyxiants in a combustion atmosphere. – IEC 89/650/FDIS

7. Smoke and Acidity are not an issue in public nor in engineering
  Cable are usually not visible construction products and so mainly unknown nor for architects and construction engineers. Regarding fire hazard, smoke in case of fire is not a new requirement for many other construction products. Acidity is a new requirement which is linked to the incapacitation gases which decrease the escape time in combination with the smoke density.
8. Which materials the cable Industry can use for cable manufacturing?
  The cable industry provides cables based on PVC, PE and other technologies accordingly with customers' needs. The main objective of the cable Industry is to supply the End-users with the most appropriate type of cable for each application.
When safety is concerned and a reliable and competitive solution is available, the cable Industry is fully supporting the safer solution without limitation of technology nor material.
9. The ‘Fire Gases Analysis from Burning Cables’ funded by EUROPACABLE has been accepted by the Scientific Community?
  The research became in 2005 an official ISO working document. The results have been published in ISO.
10. The ‘Fire Gases Analysis from Burning Cables’ funded by EUROPACABLE focus the toxic potency of effluents?
  No, the target is to demonstrate that cables which fail acidity class a1, emit gasses that reach in few seconds the incapacitation threshold (0.3 FEC and/or 0.3 FED as per ISO 13571)
11. Why adopting FIPEC fire Scenario (prEN50399)?
  To be coherent with EC that adopted first the FIPEC1 Scenario as suggested by the Fire Regulators Group on 31st March 2004. Moreover additional technical reasons can be highlighted:
  1. The validity of this Scenario has been proven by the FIPEC research; it demonstrate that the vertical installation is the tough one.


  2. The reproducibility and repeatability of the prEN50399 Test Method – which is based on the FIPEC Scenario 1 – has been proven by a recent Round-Robin organized by CENELEC TC20 WG10 and carried out by 18 European labs
(1) FIPEC - Fire Performance of Electric Cables – (omissis) The FIPEC research program (budget 1 MEURO) was set up to develop methods for measuring the fire performance of electric cables (FIPEC) based on sound engineering principles rather than prescriptive tests as the former will help facilitate the use of good measurement techniques and the introduction of fire engineering in this field. (omissis) www.sp.se/en/index/research/Fipec/Sidor/default.aspx
12. Why adopted FTIR for gas Analysis?
  The validity of FTIR1 to analyze the fire effluents has been proven by the SAFIR Research Programm2. The SP and LSF laboratories took part to the SAFIR Research Programm. A recent additional work carried by SP confirmed the validity of such method for analyzing fire effluent compositions during a fire test.

(1) FTIR - Fourier transform infrared spectroscopy - Fourier transform spectroscopy is a measurement technique whereby spectra are collected based on measurements of the temporal coherence of a radiative source, using time-domain measurements of the electromagnetic radiation or other type of radiation. It can be applied to a variety of types of spectroscopy including optical spectroscopy, infrared spectroscopy (IR), nuclear magnetic resonance, mass spectrometry and electron spin resonance spectroscopy.

(2) SAFIR (Smoke Gas Analysis by Fourier Transform Infrared Spectroscopy) project - Work performed within the European Standards, Measurement and Testing program under Contract no. SMT4-CT96-2136. The project was initiated in February 1997 by the Commission of the European Communities, DG XII, in the SMT research program.

FAQ on CPD
1. What is CPD? What has it got to do with wiring and cabling?
  The Construction Products Directive was published by the EC in 1989. Its purpose is the removal of technical barriers between EU Member States in the construction field for products used in buildings and civil works. It identifies six essential requirements against which products may be assessed. Wires and cables are mainly concerned by the second Requirement, which is “Safety in case of fire”1, which includes reaction to fire and resistance to fire.

(1) Safety in case of fire
The construction works must be designed and built in such a way that in the event of an outbreak of fire:
  • the load-bearing capacity of the construction can be assumed for a specific period of time,
  • the generation and spread of fire and smoke within the works are limited.
  • the spread of the fire to neighbouring construction works is limited,
  • occupants can leave the works or be rescued by other means.
  • the safety of rescue teams is taken into consideration”

2. What is reaction to fire? Is it the same as resistance to fire?
  Reaction to fire concerns what happens when a cable burns. Under the CPD, it is assessed on real size cable samples in terms of the amount of heat released, the spread of flames, the emission of smoke and release of flaming droplets/particles and acidity. These parameters are used to gauge to what extent the cables may contribute to the development of a fire.

For cables, the Directive sets out different classes of Reaction to Fire performance in a table called “Classes of reaction-to-fire performance of electric cables” (hereafter referred to as ‘the Euroclass Table’).

The Euroclass Table defines seven classes (A, B1, B2, C, D, E, and F). Heat release and flame spread together with the additional requirements regarding smoke production, flaming droplets and acidity are the classification criterion.

Resistance to fire is the term used to describe how long a cable continues to operate in a fire. This may be of primary concern, for instance, in life safety installations. The Resistance-to-Fire performance of cables is indicated in terms of survival time. The times are 15, 30, 60, 90 and 120 minutes of operation in a standardized fire condition.
3. Which cables are actually covered by the CPD, and for which applications? Which cables require certification?
  All cables that are permanently incorporated (fixed installation) into a building – whether residential, or commercial, or industrial – and into other civil works are covered by the CPD. This includes power cables of any rated voltage, as well as communication cables with metal and glass (optical fibre) conductors. For cables installed in works where National Regulations prescribe a specific Classification, conformity to Standards must be certified.
4. Is this Euroclass Table official? How will this table be applied?
  The Euroclass Table of Reaction to Fire of cables was officially published as Decision n° 2006/751/CE published in the EC Official Journal on 27 October 2006. (The Resistance to fire classification was made official in Decision n° 2000/367/EC)

The mandatory application of these Decisions in Member States requires four conditions:
  • That the relevant National Authorities transpose the classifications in their National Regulations
  • That the National Regulations indicate which class is applicable in which application
  • That the necessary standards are issued under Mandate of the Commission and published in the European Official Journal
  • That the National Authorities notify the Commission the Approval Bodies (third party) approved for the Certification of the particular product.
This process will take time as it will require consultation at various levels and preparation and publication of a number of supporting standards. Until this happens, there can be no regulatory requirement to use product certified in accordance with the Euroclass table.
5. But what is going to happen in practice? What does this mean for the future?
  In practice, there needs to be clarity regarding products.

The Euroclass Table sets out very specific tests to determine the performance to be fulfilled by a product to belong in a particular Class.

In order to allow the Certification of a given product according to the Euroclass Tables, a standard must be created by CENELEC on mandate from the Commission. Once this has been done certified products will become available, which will carry CE Marking under the CPD together with a declaration of the achieved Euroclass. Until then, no other marking referring to the CPD will be valid, and any reference suggesting that a cable is ‘CPD approved’ or the like will be incorrect and misleading.
6. Does this mean that today it is impossible to buy any CPD compliant cable?
  The framework to certify whether any cable on the market is ‘CPD compliant’ is under development. Work is in progress to have tests conducted to establish how existing cables perform using the fire tests that underpin the Euroclass categories, and cable manufacturers will undoubtedly conduct such tests as part of the process leading to the development of cables meeting the various Euroclasses.

The results of such tests however cannot be used to validate any kind of ‘CPD compliance’. Therefore until CENELEC has completed its work, new standards have been issued, certification bodies notified and new products released and certified accordingly, there will be no such thing as a CPD “CE” marked cable on the market.
7. How will we know that these certified products are fit for purpose?
  The Commission has decided that for all the higher performance classes (A, B1, B2, and C), cables require the so called ‘1 + Attestation of Conformity System’. This requires an accredited third party certification organisation to carry out initial type testing and assessment of factory production control, as well as subsequent continuous surveillance including the verification of samples taken at the factory or from the marketplace.

This certification system will help ensure that key parameters affecting safety in the use of cables in fire conditions are properly controlled.
8. How long will it take before these products are available? What happens in the meantime?
  The tasks described above are indeed going to take some time to complete. For the moment, the existing products will continue to be used as before.
9. If fire performance products are already available, what are the CPD and new rules and regulations going to contribute?
  The Euroclass Table finally takes into account the entire behaviour of cables in fire, dynamically measured against time on real size samples. This is an important step forward in fire safety and allows National Authorities to treat cables in a similar manner to other construction products already covered by the CPD.

Euroclass Table classes are likely to become a standard feature of building regulations in Europe, though they are likely to be applied differently across the EU. Indeed each country, under the principle of subsidiarity, will decide how these classes are to be used in its construction standards and/or regulations. It should be noted that it is not mandatory for classification to be introduced into National regulations; some countries may take the decision to address this issue in other ways.

These classes will however certainly become a point of reference as, whatever their application, they will be common to all countries. The performance level of the products that will eventually be certified under the classes will be clearly understood by all European decision makers. The products brought to market will comply with strenuous testing requirements, and continue to ensure that the safety of persons, animals and goods in fire hazards is protected as much as possible.
10. How will I be informed of further progress with the CPD?
  Europacable and its members will endeavour to ensure that regular communication is maintained throughout the electro-technical and construction industries regarding progress achieved in this process.