SOUTH AFRICAN NATIONAL STANDARD

Transcription

1 ISBN SOUTH AFRICAN NATIONAL STANDARD The use and control of fire-fighting equipment Part 1: Portable and wheeled (mobile) fire extinguishers Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001 Tel: Fax: SABS

2 Table of changes Change No. Date Scope Amdt Amended to update the requirements for site inspection, and to add a table for the evaluation of fire classes. Foreword This South African standard was approved by National Committee SABS SC 21A, Fire safety Fire-fighting equipment, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in March This document supersedes SANS :2005 (edition 3). A vertical line in the margin shows where the text has been technically modified by amendment No. 1. Annex A is for information only. Introduction Fire extinguishers are intended as a first line of defence against fires of limited size. They are needed even if the property is equipped with automatic sprinklers, standpipe and hose, or other fixed protection equipment. This part of SANS is intended to provide recommendations on the selection, installation, inspection and use of fire extinguishers, but these will be of real value only if personnel are available who are trained in the recognition of the types and use of fire extinguishers. Every opportunity should therefore be taken to train personnel in the use of fire extinguishers and to demonstrate the performance of fire extinguishers. Because maintenance is the owners' responsibility, owners should make certain that the people doing the maintenance work comply with legislation. It should be borne in mind that compliance with the provisions of this standard does not absolve the user from having to comply with the relevant statutory regulations. It should also be recognized that the recommendations provided herein might not be applicable to all risks where specific configurations of combustible materials, or other special locations or circumstances, dictate the need for engineered protection. Although portable fire extinguishers are not fixtures in a building structure, they form part of the whole concept of fire protection. Their supply in new buildings is compulsory in terms of the National Building Regulations and it is recommended that the provision and siting of portable fire extinguishers are considered at the design stage.

3 Contents Page Foreword Introduction 1 Scope Normative references Definitions Requirements Selection of extinguishers Provision of extinguishers Site control Reconditioning Mobile fire extinguishers... 7 Annex A (informative) Extinguisher types and their application techniques... 8 Bibliography

4 This page is intentionally left blank 2

5 The use and control of fire-fighting equipment Part 1: Portable and wheeled (mobile) fire extinguishers 1 Scope This part of SANS gives the requirements for the selection, installation, inspection and use of portable and mobile fire extinguishers. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this standard. All standards are subject to revision and, since any reference to a standard is deemed to be a reference to the latest edition of that standard, parties to agreements based on this standard are encouraged to take steps to ensure the use of the most recent editions of the standards indicated below. Information on currently valid national and international standards can be obtained from the SABS Standards Division. SANS , Symbolic safety signs Part 1: Standard signs and general requirements. SANS , The production of reconditioned fire-fighting equipment Part 1: Portable and wheeled (mobile) rechargeable fire extinguishers. SANS 1910, Portable refillable fire extinguishers. SANS T, The application of the National Building Regulations Part T: Fire protection 1). 3 Definitions For the purposes of this part of SANS 10105, the definitions given in SANS , SANS 1910 and the following definitions apply: 3.1 class A fire fire involving solid materials, usually of an organic nature, in which combustion normally takes place with the formation of glowing embers 1) Some of the documents listed as normative references in clause 2 might still be at DSS (public enquiry) stage. Users of this document should be aware of the possibility that such referenced documents are not yet final and might change. 3

6 3.2 class B fire fire involving liquids or liquefiable solids 3.3 class C fire fire involving class A fire, class B fire and class D fire occurring in the presence of energized electrical equipment 3.4 class D fire fire involving metals 3.5 class F fire fire involving fat and cooking oil in the kitchen environment NOTE In recent years the development of high-efficiency cooking equipment, and the widespread use of vegetable oils with high auto-ignition temperatures, has highlighted the need for a new class F fire. 3.6 responsible person person (being the owner of the building or a person appointed in writing by the owner) who is responsible for the site control of fire extinguishers and for keeping the necessary records 3.7 risk environment under which a fire can occur 4 Requirements (see also SANS T) 4.1 General Extinguishers shall be maintained in a fully charged and operable condition, and shall be kept in their designated places at all times when they are not being used Extinguishers shall be conspicuously located where they will be readily accessible and immediately available in the event of fire. They shall preferably be located along normal paths of travel, including exits from areas, and their positions shall be identified by means of signs complying with the provisions of SANS Extinguishers shall not be obscured from view, except where their positions are clearly marked, and they shall be kept in a readily accessible, unobstructed, and where necessary, demarcated position When mounted or placed in their intended location, the operating instructions shall face outwards or towards the most likely direction of access Wherever possible, extinguishers shall not be placed in dead-end areas (where access could present a risk to the potential operator), behind doors, in cupboards (except purpose-made cabinets or cupboards) or in deep recesses, or in positions where they might cause obstruction to exit routes or be damaged by trolleys or other vehicles. Extinguishers shall not be placed over or close to heating appliances. 4.2 Installation Extinguishers shall be installed on brackets, or in cabinets, unless the extinguishers are of a wheeled type. 4

7 4.2.2 Extinguishers installed under conditions where they might be subject to dislodgement shall be installed in specifically designed brackets Extinguishers installed under conditions where they might be subject to physical damage shall be protected from impact Extinguishers shall be installed with the carrying handle of the extinguisher not more than 1,5 m above the floor. The clearance between the bottom of the extinguishers on brackets and the floor shall not be less than 3 cm Where extinguishers are installed in closed cabinets that are located outdoors, or are exposed to elevated temperatures, such cabinets should be provided with ventilation openings. 5 Selection of extinguishers (see also annex A) 5.1 General The selection of extinguishers for a given situation shall be determined by, amongst others, the character and extent of the fires anticipated, the construction and occupancy of the individual property, the hazards to be protected against, and the ambient temperature conditions. The number, rating, placement and limitations of use of the required extinguishers shall meet the requirements of SANS T. 5.2 Selection according to risk Extinguishers shall be selected for protection against specific fire risks Extinguishers for protection against class A fires shall be selected from extinguishers with the appropriate class A rating (see SANS 1910) Extinguishers for protection against class B fires shall be selected from extinguishers with the appropriate class B rating (see SANS 1910) Extinguishers for protection against class C, class D and class F fires shall be selected from extinguishers with the appropriate rating. NOTE Extinguishers containing media other than powder are relatively ineffective on pressurized flammable liquids and pressurized gas fires The system used to rate extinguishers for class B fires (flammable liquids in depth) is not directly applicable to three-dimensional class B risks involving class B materials in motion, such as pouring, running or dripping flammable liquids. These shall be selected on the basis of recommendations by the manufacturers of the extinguishers. NOTE The installation of fixed systems for such risks should be considered when applicable Wheeled extinguishers shall be considered for risk protection in high risk areas or where high media flow rates, increased media stream range, or increased media capacity are required. 6 Provision of extinguishers 6.1 General The minimum number of extinguishers needed to protect a risk shall be determined as outlined in SANS T. Additional extinguishers may be installed to provide more suitable protection for special risks. 5

8 6.1.2 Extinguishers shall be provided for the protection of both the building structure, if combustible, and the risks contained therein On each floor level, the area to be protected and the travel distances shall be based on extinguishers installed in accordance with SANS T The type of fire extinguisher shall, for the occupancy in which it is installed, have a capacity or mass of charge in accordance with the provisions of SANS T. 6.2 Exposure to excessive heat and cold As the operation of extinguishers is affected by temperature, to prevent the possibility of failure, extinguishers shall not be exposed to temperatures higher than 55 C or lower than 0 C, unless otherwise specified or allowed by the manufacturer. 6.3 Avoidance of corrosion Although extinguishers have a fairly high corrosion resistance, they shall not be positioned where they may be exposed to the elements, to unduly corrosive atmospheres or to splashing by corrosive liquids, except in specific pre-determined cases. 7 Site control 7.1 Site inspection To ensure the accessibility, reliability and usability of all extinguishers on site, a responsible person shall be nominated to inspect them at least once a month, or more frequently when circumstances so require. The following aspects shall be checked during the inspection: a) whether the extinguisher is in its assigned position and is of the correct type and size; b) whether access to and visibility of the extinguisher are not obstructed; c) whether the location of the extinguisher (see and 4.1.3) is identified; d) whether the operating instructions on the extinguisher are visible and facing outward; e) whether any seals have been broken; f) whether the extinguisher and its mountings have been physically damaged or have corroded; g) whether the extinguisher shows signs of leakage or the nozzle shows signs of blockage; h) whether pressure indicating devices, if fitted, are in the operating range; and Amdt 1 i) whether the service due date on the reconditioning label has expired. 7.2 Action When relevant, the following actions shall be carried out during site inspection: a) Correct the position, access and visibility of the extinguisher (see 7.1(a), (b) and (d)). b) If any of the other checks given in 7.1 show that an extinguisher might have been tampered with, or is damaged, impaired, leaking, undercharged or overcharged or that the service due date has expired or that the extinguisher is due for reconditioning or is obviously corroded, arrange for reconditioning of the extinguisher in accordance with SANS

9 7.3 Inspection records A record (initialled by the responsible person) shall be kept of each inspection, showing: a) the date on which the inspection was performed; b) the extent of any observations; c) a means of identifying any extinguisher that was found to require reconditioning; and d) whether all necessary reconditioning was arranged. 8 Reconditioning The reconditioning of fire extinguishers (which includes overall maintenance, internal inspection and pressure testing) shall be carried out in accordance with the requirements of SANS Mobile fire extinguishers 9.1 A mobile fire extinguisher may replace half of the required portable fire extinguishers, provided that: a) the capacity of any such mobile fire extinguisher is equal to the combined capacity of the number of portable fire extinguishers it replaces; b) it contains the same extinguishing medium as required for such portable extinguishers; c) it replaces such portable extinguishers only on the floor and within the division concerned; d) the floor area to be served is in accordance with the requirements of SANS T; e) such mobile fire extinguisher is kept in a readily accessible, demarcated and unobstructed position; and f) permission for its installation is obtained from the local authority. 9.2 If so required by the appropriate local authority, the capacity may exceed that given in (a) above. 9.3 The information given in terms of 9.1(a) to 9.1(f) shall be added in the record book that is kept by the responsible person (see 7.3). 7

10 A.1 Water types A.1.1 General Annex A (informative) Extinguisher types and their application techniques Water type extinguishers are intended primarily for use on class A fires. When extinguishing a fire, the stream of water is directed towards the base of the flames and, after the flames have been extinguished, generally at any smouldering or glowing surfaces. Application should begin near but at a safe distance from the fire (usually (4 m to 5 m), as some burning or heated solids can explode on contact with cold water. Deep-seated fires should be thoroughly soaked and, if necessary, broken apart to extinguish the fire completely. A.1.2 Stored-pressure water extinguishers The container of a stored-pressure water extinguisher is charged with water up to the liquid-level indicator and is then pressurized with gas or air which provides the expellent force to discharge the water. The extinguisher is operated by means of an actuating mechanism that opens a sealing device or discharge valve. A.2 Foam types Foam type extinguishers are generally intended for use on class A and class B fires. During operation on class B fires, the extinguishing medium should not be directed into the burning liquid as agitation of the liquid may occur, resulting in spillage. Where the depth of the flammable liquid in the tank or vat is appreciable, best results are obtained when the discharge is directed just above the burning liquid surface and against the inside wall furthest from the operator, so as to permit the natural spread of the foam over the burning liquid. If this is not possible, the operator should stand far enough away from the fire to allow the foam to fall lightly upon the burning surface and, where possible, walk around the fire while directing the stream, so as to get maximum coverage during the discharge period. For fires in ordinary combustible materials (class A fires), the foam may be used to coat the burning surface directly. For flammable-liquid-spill fires, the foam may be caused to flow over the burning surface by bouncing it off the floor just in front of the burning area. Foam is not effective on flammable liquids and gases that are escaping under pressure. The manufacturer should be contacted for details on the most appropriate foam for use as some flammable liquids render certain foams ineffectual. A.3 Gas type A.3.1 General The only gas type extinguisher in common use is the carbon dioxide extinguisher. This type of extinguisher is primarily intended for use on class B and class C fires. It has a limited range and is affected by draft and wind. On all fires, the discharge should be directed towards the base of the flames and, even after the flames have been extinguished, it should be applied onto the surface that was burning, to allow more time for cooling and to prevent possible re-ignition. 8

11 The most commonly used method for the application of a gas type extinguishing medium on contained flammable-liquid fires is to start at the near edge and, whilst directing the discharge in a side-to-side sweeping motion, gradually progress towards the back of the fire. If this is not possible, the discharge horn should be directed downwards at an angle of approximately 45 and towards the centre of the burning area. The horn is not moved in this case, as the discharge stream enters the fire from above and spreads out in all directions over the burning surface. For spill fires, the side-toside sweeping motion may give better results. On fires involving electrical equipment, the discharge should be directed towards the source of the flames. It is important to de-energize the electrical equipment as soon as possible, to eliminate the possibility of re-ignition. WARNING 1 Gas type extinguishing media extinguish by so diluting the surrounding atmosphere with an inert gas that the oxygen level is reduced below the level required for combustion. When this type of extinguisher is used in an unventilated space such as a small room or cupboard, prolonged occupancy of that space may cause the user to lose consciousness as a result of oxygen deficiency. WARNING 2 When using this type of extinguisher, the insulating handle of the discharge horn shall be held to avoid the danger of frost-bite and the possibility of receiving a shock due to the build-up of static electricity. A.3.2 Carbon dioxide (CO 2 ) extinguishers The carbon dioxide is retained under its own pressure in a liquid state at room temperature. The extinguishing medium is self-expelling and is discharged by operation of a valve. The carbon dioxide is expelled, in its vapour and solid phase, through a horn. The horn may be attached to the valve assembly by means of a metal swivel joint connector on small models or by a length of flexible hose on larger models. A.4 Halon types In terms of the Montreal Protocol, halon extinguishers have been declared environmentallyunfriendly and should be replaced with an acceptable type of extinguisher (see SANS ). A.5 Dry-powder types A.5.1 General Dry-powder type extinguishers are intended for use on class A, class AC, class B, class BC, or class D fires, depending on the type of dry powder contained in the extinguisher. When the extinguishing medium is applied to a class A fire, it is important to try to coat all burning areas in order to eliminate or minimize the number of small embers which are a potential source of reignition. The extinguishing medium itself has little cooling effect and cannot penetrate below a burning surface. For this reason, deep-seated fires will be extinguished only if the extinguishing medium is discharged directly onto the burning material or if the burning material is broken apart and spread out. On flammable-liquid fires, the stream of powder should be directed towards the base of the flames. Best results are generally obtained by attacking the near edge of the fire and progressing towards the back of the fire whilst moving the nozzle in a side-to-side sweeping motion. The initial discharge 9

12 should not be directed directly at the burning surface at a range closer than 2 m because the high velocity of the stream may cause splashing or scattering of burning material. The extinguisher should be given a short trial discharge away from the fire first, to obtain some idea of a safe distance from which to start the attack on the fire. Extinguishers for use on class D fires differ from those used on class A and class B fires in respect of working pressure, discharge nozzle and the type of powder. As a class D fire is one of the most dangerous and is very difficult to extinguish, the fire-fighting technique differs radically from that employed on class A and class B fires. It is therefore recommended that expert advice be obtained where there are class D fire risks. A.5.2 Stored pressure dry-powder extinguishers The extinguishing medium is a powder, specially treated and in a finely divided form. Typical extinguishing media of this type have a sodium bicarbonate, potassium bicarbonate, potassium chloride or ammonium phosphate base. The extinguisher is operated by depressing a plunger or lever that pierces or opens a sealing device and releases the charge. The powder is discharged through a nozzle via a control valve that allows for intermittent discharge. NOTE Performance requirements for stored pressure dry-powder extinguishers are given in SANS A.5.3 External cartridge-operated dry-powder extinguishers The extinguishing medium used in a cartridge-operated dry-powder extinguisher is the same as that used in a stored-pressure dry-powder extinguisher, but the expellent is kept in a gas cartridge that is mounted externally on the extinguisher. Extinguishers with internally mounted cartridges may not be used for the purpose of fire fighting and should be replaced with an approved fire extinguisher (see SANS ). The extinguisher is operated by opening a valve or by depressing a lever or plunger to cause the actuating device to pierce the sealing disc of the gas cartridge and so release the expellent and pressurize the container. The powder is discharged through a nozzle via a control valve. A.6 Wet chemical extinguishers The extinguishing medium is comprised of a solution of water and potassium-based chemicals. On class F fires, the medium cools the fire and causes the hot oil to solidify. The medium is discharged as a fine spray which reduces the possibility of splashing hot oil. A.7 Evaluation of fire classes For evaluation of fire classes, see table A.1. 10

13 Table A.1 Evaluation of fire classes Extinguishing medium Classes A B C D F Water MS D D D D Foam S MS D D D Powder ABC a S MS S LS U Powder BC b U MS S U U CO 2 LS S MS D D Wet chemical U U U U MS S = Suitable MS = Most suitable D = Dangerous U = Unsuitable LS = Less suitable a b Used for extinguishing a combination of class A, B and C fires. Used for extinguishing a combination of class B and C fires. Amdt 1 Bibliography ISO , Fire protection Portable and wheeled fire extinguishers Part 1: Selection and installation. SABS 11

14 This page has been left blank intentionally

15 SABS Standards Division The objective of the SABS Standards Division is to develop, promote and maintain South African National Standards. This objective is incorporated in the Standards Act, 2008 (Act No. 8 of 2008). Amendments and Revisions South African National Standards are updated by amendment or revision. Users of South African National Standards should ensure that they possess the latest amendments or editions. The SABS continuously strives to improve the quality of its products and services and would therefore be grateful if anyone finding an inaccuracy or ambiguity while using this standard would inform the secretary of the technical committee responsible, the identity of which can be found in the foreword. Tel: +27 (0) Fax: +27 (0) The SABS offers an individual notification service, which ensures that subscribers automatically receive notification regarding amendments and revisions to South African National Standards. Tel: +27 (0) Fax: +27 (0) sales@sabs.co.za Buying Standards Contact the Sales Office for South African and international standards, which are available in both electronic and hardcopy format. Tel: +27 (0) Fax: +27 (0) sales@sabs.co.za South African National Standards are also available online from the SABS website Information on Standards The Standards Information Centre provides a wide range of standards-related information on both national and international standards, and is the official WTO/TBT enquiry point for South Africa. The Centre also offers an individual updating service called INFOPLUS, which ensures that subscribers automatically receive notification regarding amendments to, and revisions of, international standards. Tel: +27 (0) Fax: +27 (0) info@sabs.co.za Copyright The copyright in a South African National Standard or any other publication published by the SABS Standards Division vests in the SABS. Unless exemption has been granted, no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means without prior written permission from the SABS Standards Division. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any purpose other than implementation, prior written permission must be obtained. Details and advice can be obtained from the Senior Manager. Tel: +27 (0) Fax: +27 (0) info@sabs.co.za