9 months ago

ECOBuilder-Specifiers Journal spring2018

Fire Safety and Building

Fire Safety and Building Regulations Industrial Textiles & Plastics The tragic events of 2017 focused the attention of the nation on fire prevention and control in UK buildings. Fire safety testing and evaluation of building materials is ongoing, and UK Building Regulations are under review. With new, more stringent standards inevitable, what do today’s specifiers need know about flame retardant construction materials? Who, and what, is to blame for the fire tragedy that claimed the lives of seventy-one people? The Grenfell Tower Inquiry is ongoing, but it will be many months before conclusions are announced. In the meantime, the government published Building a Safer Future – Independent Review of Building Regulations and Fire Safety: Interim Report in December. In the report, Dame Judith Hackitt said, “It has become clear that the whole system of regulation, covering what is written down and the way in which it is enacted in practice, is not fit for purpose, leaving room for those who want to take shortcuts to do so.” Among the key findings of her interim report are that current regulations and guidance are too complex and unclear, and that the system of product testing, marketing and quality assurance is not clear. Those who commission, design and build a project must all take responsibility for ensuring that buildings are fit for purpose, and that “cutting corners” is not acceptable. As Grenfell has demonstrated, this is especially critical for flame retardant building materials. Dame Judith concluded that products must be properly tested and certified, and that the marketing of these materials must be clear and easy to interpret. Those who manufacture the materials used 10 12 ECOBUILDER - THE SPECIFIER 2018 SPRING 2018 in construction must also take responsibility for ensuring that what they provide to the industry is produced to the highest standards and that product specifications are confirmed by independent testing and accreditation. The challenge, for both manufacturers and specifiers, is understanding and interpreting flame retardant standards, as well as the testing procedures and protocols used to determine the flammability of a material. British and international building standards specify flame retardant materials for specific installations and structures. Flame retardant additives are incorporated in the materials or added as a coating to make them flame retardant; it is the formulation, quality and amount of these additives, and the equipment used to produce them that determine which flame retardant tests the material will pass and what standards to which they will comply. A flame retardant material is one that self-extinguishes; it does not mean that it is flame proof. Flame retardant materials are resistant to catching fire, reduce flammability, and inhibit, suppress or delay the production of flames. Flame proof materials are ones that are not liable to catch fire or be damaged by fire and are not readily ignited or burned by flames. Current building regulations in England regarding fire safety matters within and around buildings are specified in Approved Document B (Fire Safety) Volume 1 (dwelling houses) and Volume 2 (buildings other than dwelling houses). The documents specify the minimum standards for all materials used in the construction, with specific installation requirements. (The full document is available online at The required standard in Britain is BS 476 (fire tests on building materials and structures) Parts 6 and 7. Part 6 (method test for fire propagation for products) tests the amount of heat given off during a 20-minute test, with measurements being taken frequently to produce an Index result. Part 7 (method of test to determine the classification of the spread of flame of products) measures how far and how fast the flame spreads from the point of ignition over the test time. Materials are rated Class 1 (best) to Class 4 (worst), depending on the spread and speed of the flame. To achieve a Class 1 rating in BS 476 Part 7, the flame must not spread more than 165mm from the point of ignition over a test time of 10 minutes. EN ISO 13501-1 was introduced in 2002 to harmonize the classification of the reaction to fire for building materials. This is also an accepted standard in the UK for

Euro Fire Class System and National Fire Class Systems* Euro Class EN ISO 13501-1 UK BS 476 Parts 6 & 7 Class A1 NA A1 Class A2 Class 0 A2 Class B Class 0 B1 Class C Class 1 B1 Class D Class 1 B2 Class E Class 2 B2 Class F Class 3 B3 EN ISO 13501-1 STANDARDS FIRE BEHAVIOUR Class A1 – highest level non-burnable Class A2 – non-burnable materials Class B – inflammable materials Class C – normal flammable Class D – normal flammable Class E – normal flammable Class F – not classified materials SMOKE DEVELOPMENT Germany DIN 4102 *Indicative purposes only; test methods and standards vary Class S1 – very limited smoke Class S2 – limited smoke Class S3 – no demands on smoke BURNING DROPLETS Class d0 – no droplets or particles Class d1 – limited burning droplets Class d2 – no demands on droplets Highest level for flame retardancy B-s1, d0 Building Regulations, along with BS 476 Parts 6 & 7. Two test standards make up EN ISO 13501-1: EN ISO 11925-2 (ignitability when subjected to direct impingement of flame) and EN ISO 13823 (SBI) (reaction to fire tests exposed to thermal attack by a single burning item). The European standard has a wider scope than BS 476, as it measures flame spread, heat release and toxicity of smoke. Tests are conducted by, and products accredited by, third-party certification bodies. Because a material has passed a national test, it cannot be assumed that it would have the equivalent Euro Class rating unless the material has been specifically tested to these standards. Understanding that not all “flame retardant” products are equal necessitates understanding the different standards, different testing procedures and varying “pass” results for different countries. For example, to pass EN ISO 13501-1, the flame spread must not exceed 150mm within 60 seconds (when exposed to flame for 30 seconds), which is more stringent than for BS 76 Part 7. UK Building Regulations also consider building height, occupancy and fire severity as determining factors. The highest ratings for flame retardancy are Class 1 (UK) and Euro Class B-s1,d0, both accepted testing standards in Approved Document B. But what is Class 0, listed in Building Regulations as the highest standard required? This is not a UK fire test rating, rather it is a classification specified in the Building Regulations. It means that the material is either non-burnable or achieved a Class 1 (BS 476 Part 7) result and a Class 1 (BS 476 Part 6) Index not more than 6 (after 90 seconds and not more than 12 (after 20 minutes). Euro Class A1 and A2 are given to materials that are non-burnable products. See the table for an approximate guide to the different standards. In her interim report, a “shocked” Dame Judith stated, “I am convinced of the need for a new intelligent system of regulation and enforcement for high-rise and complex buildings which will encourage everyone to do the right thing and will hold to account those who try to cut corners.” Until that brave new world arrives, every manufacturer of flame retardant building products has a duty and a responsibility to have their products independently tested and accredited by third-party accreditation bodies, and to present the results to consumers, be they specifiers, contractors or installers, clearly and unambiguously. Equally, specifiers and contractors have the responsibility to understand precisely what “flame retardant” means for the building products they are employing in any construction, large or small. MARC VAN DER VOORT Managing Director, Industrial Textiles & Plastics Ltd ITP produce engineered materials for the construction industry, with specialist expertise in flame retardant technology, supplying POWERLON® FR membranes and FlameOut TM house wraps. ECOBUILDER ECOBUILDER - THE SPECIFIER - THE SPECIFIER SPRING 2018 11 13

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