BEDFORDSHIRE FIRE AND RESCUE SERVICE FIRE SAFETY GUIDANCE NOTE NO 40

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1 BEDFORDSHIRE FIRE AND RESCUE SERVICE FIRE SAFETY GUIDANCE NOTE NO 40 DANGEROUS SUBSTANCES AND EXPLOSIVE ATMOSPHERES REGULATIONS 2002 STORAGE OF PETROLEUM SPIRIT AND OTHER HIGHLY FLAMMABLE LIQUIDS IN CANS, DRUMS AND OTHER CONTAINERS 1 Introduction The primary legislation applying to the control of substances that can cause fires and explosions in the workplace is the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) (SI 2002 No.2776). The storage of petroleum spirit and mixtures of petroleum was licensable prior to the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR). The Petroleum (Consolidation) Regulation 2014 has subsequently amended the requirement for licensing petroleum except for specific limited storage in domestic or premises that are not deemed a work place (up to 275 litres provided it is not for sale / dispensing. The regulation provides detail on relevant quantities that can be stored for domestic and other relevant uses, FSGN 39 provides further details. The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) provides the detail for the storage requirements of flammable liquids. Under Section 5 of DSEAR a risk assessment is required for storage at a workplace of flammable liquids including petroleum (and other dangerous substances such as acetylene) and the original guidance for the storage of petroleum could be used as a benchmark for that risk assessment. There is a requirement in Section 6 of DSEAR very similar to that in Article 12 of the Regulatory Reform (Fire Safety) Order 2005 (FSO) to reduce or eliminate the risk, with a preference for replacement in order to eliminate the risk. 2 Standards of Storage The storage of petroleum spirit, mixtures of petroleum and highly flammable liquids should be in accordance with the standards specified in the Health and Safety Series booklet HSG51 'The Storage of Flammable Liquids in Containers (HSE Books). THE FOLLOWING SECTIONS ARE FOR GENERAL GUIDANCE ONLY AND DO NOT REFER TO ALL PARTS OF THE ABOVE STANDARDS. THEY MUST NOT BE CONSTRUED AS REPRESENTING THE FULL RECOMMENDATIONS IN RESPECT OF ANY SPECIFIC PROPOSALS FOR STORAGE. Storage in retail premises or laboratories etc is covered in HSG Fsgn 40

2 3 Siting and Construction All storage areas and buildings, rooms, cupboards and bins used for storage of petroleum spirit, petroleum mixtures and highly flammable liquids, should be sited and constructed in accordance with the standards specified in HSG 51. Alternative designs, materials and methods may be suitable where they provide an equivalent or higher overall level of safety. 3.1 Storage is Satisfactory in the Following Locations: a. In the open air. b. In separate buildings. c. In stores forming part of other buildings. 3.2 Storage in Open Air: Containers in the open air should be sited in a well ventilated position away from sources of ignition. The location should minimise the effect of heat on the containers from a fire within the premises or outside the boundary. It should also minimise the effect of a fire at the container store on buildings, plant and people, inside or outside the premises. Containers should be stored within a clearly-defined area on a concrete pad or other impervious surface. The minimum distance between the edge of the area and any occupied building, boundary, process unit or fixed source of ignition, should be as set out in the following table. In some cases, it may be necessary to increase the separation distance or provide additional protection; for example, if there are problems with the local water supply, or if the site is remote, or if it is close to process plant. 3.3 Minimum Separation Distances: Quantity stored: litres (l) Distance from occupied building, boundary, process unit, flammable liquid tank or fixed ignition source: metres(m) Up to , ,000 and above 7.5 Notes: a. The maximum stack size should be 300,000 litres, with at least 4 metres between stacks. b. Containers should not be stored within the bund of a fixed flammable liquid tank, or within 1 metre of a bund wall. 2 Fsgn 40

3 If adequate separation distances cannot be achieved, they may be reduced in appropriate cases, as long as an adequate fixed water-spray cooling system or fixed fire equipment is provided. Alternatively, a fire wall of an approved standard may be used. Prior advice should be sought from the Fire and Rescue Service. A fire wall should be imperforate, of at least half hour fire resistance, weather resistant, and sufficiently robust to withstand foreseeable accidental damage. Means of controlling spillage should be provided. This may be an impervious sill or low bund, typically 150 mm high, big enough to hold 100% of the contents of the largest container. An alternative is to drain the area to a safe place, such as a remote sump or a separator. Absorbent granules or other means of clearing up small spills should be provided. The surface of the storage area should be sloped so that any spillage does not accumulate around containers, but can drain to an evaporation area (within the storage area or separate from it) or to a sump or interceptor. No combustible material (including vegetation) should be permitted in the storage area, or within 1 metre of the sill or bund wall. Weedkiller containing sodium chlorate should not be used to kill the vegetation because of the increased fire hazard. Containers should be filled to allow adequate ullage space (about 5%) for liquid expansion. Shading from direct sunlight is not needed unless the material stored is unstable, or exceptionally if adequate ullage is not provided. Any shading or weather protection for open-air stores should be in the form of a light non-combustible roof structure, with open sides which do not restrict ventilation. In order to prevent trespassing or tampering, storage areas should be enclosed by a substantial fence at least 1.8 m high, unless the storage is otherwise protected; for example, by being within the security area of larger premises. The fence should not obstruct ventilation. Suitable types include welded mesh and chain-link fencing. At least two separate exits should normally be provided, although one is sufficient, if the distance from any part of the store to the exit is not more than 24 m, measured around the containers. Exits should open outwards, should not be self-locking, and easily openable from inside when the store is occupied. They should be kept locked when the store is unoccupied, with access to the keys restricted to authorised persons. 3.4 Storage in Separate Buildings: If containers are stored in a building used only for that purpose, the building need not be fire-resistant if it is in a safe position. It should, however, be of generally noncombustible construction if it holds containers with a total capacity of more than 400 litres. In this case, 'safe position' means a place where the distance between the outside wall of the building and any other building, boundary etc, is at least the appropriate distance in the table at 3.3 above. Storage buildings may, however, be sited on a boundary if: a. The wall of the building on that side is a fire wall to its full height (at least 2 m), and b. either the walls of the building at right angles to the boundary are fire walls to their full height for at least 4 m from the boundary, or c. the fire wall extends along the boundary for at least 4 m beyond the store on either side and to a height of at least 2 m. 3 Fsgn 40

4 A similar standard should be applied for storage buildings located against the wall of an occupied building. If the storage building is not in a safe position, it should be a fire-resisting structure, as described below: a. Each enclosing element, eg walls, doors, windows, floors and ceilings, should be at least half-hour fire-resistant to BS 476: Parts 20 to 23. b. Exceptions are floors immediately above the ground, and tops or ceilings of single-storey buildings and of top-floor rooms. c. For doors, the insulation requirement is waived. d. No glazing is allowed in internal walls forming part of the storeroom enclosure. e. In the event of fire, the standard of fire-resistance should allow adequate time, for the alarm to be raised, for people to escape and for firefighting to be put in hand. The standard does not require the enclosure to withstand a complete burn-out of the contents. It is nevertheless, recommended that the walls be sufficiently strong and weatherproof, either concrete, masonry or of brick construction. f. External windows should be of Georgian wired glass or other material of equivalent fire-resistance and should be non-opening. g. All internal surfaces should be at least Class 1 if tested to BS 476: Part 7 (Surface Spread of Flame). Exceptions are floors and doors, as well as windows and their frames. h. Doors should be self-closing from any position, except doors which lead directly out of the building. i. Junctions between elements of construction should be bonded or firestopped to prevent or retard the passage of flame and hot gases. j. The structure should be robust enough to withstand foreseeable accidental damage. k. If surfaces of the structure are liable to be coated with residues, the structure should allow for removal of the residues without affecting its fire-resistance, or its ability to resist flame spread. 3.5 Stores Forming Part of Other Buildings: Flammable liquid stores forming part of a building used for other purposes should be of fire-resisting construction in accordance with 3.4, with the fire-resistance requirements being applied to internal as well as external walls. Such stores should not be below ground, and should be sited so that escape routes from any part of the building are not put at risk in the event of a fire. Where the total quantity of flammable liquid storage does not exceed 50 litres, it may be kept in a workroom in a suitably placed cupboard or bin conforming to the specification contained in paragraph 163 Figure 13 of HSG Fsgn 40

5 If the storeroom shares a common roof structure with the rest of the building, protection should be provided against fire spreading via the roof space. This can be done by providing half-hour fire-resisting separation, either horizontally between the ceiling of the store and the roof space or vertically in the roof space between the store and the rest of the building. If a storeroom is in the same building as residential accommodation, one hour fireresisting separation should be provided between the two but preferably with no connecting doors. If doors are necessary, they should be of at least one hour fireresistance and should be self-closing. Automatic Fire Detection is recommended in the store linked to audible alarms in the residential area. 4 Ventilation, Heating and Lighting, and Explosion Relief 4.1 Ventilation Storerooms and buildings should be adequately ventilated to disperse vapour from any leakage or spillage. A standard of at least five air changes per hour is recommended, using air bricks, louvres, etc on external walls. The openings should have a total area of at least 1% of the area of the walls and roof. For stores which form part of a larger building the store should, where reasonably practicable, have at least two external walls, in which ventilation openings can be fitted. Ventilation openings should not be provided in internal walls. Low-level openings should be above the height of any spillage-retention sill. Ventilation openings should not be obstructed by stacks of containers and should be kept free of dirt and rubbish. Ventilation openings should not be provided in any part of the building which is required to be fire-resistant (i.e. which is within the appropriate distance in the table at 3.3). Where this causes difficulties in providing adequate ventilation, it may be possible to construct the openings using intumescent materials, which in the event of fire will expand and seal the opening. An alternative is to provide mechanical exhaust ventilation, with the exhaust air routed to the open air via fire-resisting ducting. The fan motor should be located outside the ducting, either in a nonhazardous area, or protected to a Zone 2 standard (see paragraph 7). The ventilation should be kept in operation at all times and an airflow indicator, linked to an audible or visible alarm, should be fitted to give warning of failure. 4.2 Heating Any heating provided in the store should not be able to act as a source of ignition. Hot water radiators and steam pipes are generally suitable and electric heaters may be used if protected to Zone 2 standards. Screens may be necessary to prevent containers being stacked too close to hot surfaces. The hot surface of any heater should always be at a temperature below the auto-ignition temperature of any stored liquids. If a ducted warm air system is used, the heater should be located in a safe area. There should be no possibility of flammable vapour being ignited by hot surfaces and adequate ventilation of the store should be maintained. 5 Fsgn 40

6 4.3 Storage Areas External storage buildings (whether or not they are fire-resisting structures) should have a lightweight roof to act as explosion relief. For internal stores in single-storey buildings it may also be possible to incorporate this type of roof. Alternatively, relief panels may be provided in one or more walls, provided that the relief can vent to a safe place. An alternative for both internal and external storage buildings is to provide sufficient mechanical ventilation to remove flammable vapour released in the event of an incident. (See 67 and 68 of HSG51 concerning ducting and fan motors). The advice in sub-paragraph 3.3 on provision and locking of exits also applies to internal and external storage buildings, although the maximum travel distance in storage buildings with a single exit should not exceed 18 m. Container stores and storage areas should be adequately lit when in use. The average illuminance at ground level should be at least 100 lux. More detailed guidance is contained in booklet HSG38 'Lighting at Work' (HSE Books). 5 Spillage Containment In storerooms and buildings, means of containing spillage should be provided: for example, a sloping floor or a 150 mm sill across door openings. Ramps may be provided for ease of access for wheeled trolleys etc. The floor should be impermeable and inert with respect to the liquids stored. 6 Electrical Installation Electrical installations should be ATEX rated in accordance with the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 1996 (or an equivalent standard) appropriate to the area classification, which is current at the time of installation or modification. Equipment should be marked with the symbol below. Where reasonably practicable, electrical equipment should be installed in nonhazardous areas. 6.1 Electrical Certificate A periodic electrical test certificate for the installation, signed by a competent person being fully conversant with and having practical experience of the necessary standard should be available on the licensed premises. 6.2 Hazardous Areas Hazardous areas in relation to electrical equipment are classified into the following hazard zones: Zone 0: In which an explosive vapour-air mixture is continuously present, or present for long periods. Zone 1: In which an explosive vapour-air mixture is likely to occur in normal operation. 6 Fsgn 40

7 Zone 2: In which an explosive vapour-air mixture is not likely to occur in normal operation, and if it occurs, it will exist only for a short time. Areas outside these zones are defined as non-hazardous Hazardous Area Classification The following table describes a typical hazardous area classification for containers of liquids with a flashpoint of less than 32 C. The table gives general guidance only, as local conditions should always be taken into account when carrying out a classification exercise. Typical Hazardous Area Classification: Item Extent of Area Classification Storerooms Every part* Zone 2 and buildings Cupboards and Every part Zone 2 Bins Open air Vertically to 1 m above Zone 2 storage areas top of highest container, and horizontally to 1 m beyond bund or sill * Note: For rooms and buildings which are well ventilated (see sub-paragraph 4.1), areas more than 2 m above the top of the highest container can be considered safe areas. 6.3 Vehicles Vehicles which need to operate within the hazardous areas associated with container stores and storage areas, should be protected against igniting flammable vapour. Guidance on the standards of diesel-engine lift trucks in Zone 2 areas is in HSE Guidance HSG113 'Lift Trucks in Potentially Flammable Atmospheres' (HSE Books). For other vehicles, specialist advice should be obtained. Battery charging should not be carried out in hazardous areas and vehicles should not be parked in such areas. 7 Other Sources of Ignition There should be no means of igniting flammable vapour within hazardous areas associated with storage of flammable liquids. This includes portable equipment such as unsuitable heating appliances (see sub-paragraph 4.2), hand lamps and welding sets. Smoking should be prohibited and 'No Smoking' signs should be posted. If any hot work is necessary, it should be done by trained personnel in accordance with a safe system of work. Guidance on permit-to-work systems is available in INDG98 HSE Books 1997 ISBN Where hot work on a container is proposed, precautions against igniting flammable materials in the container are essential. The container should be removed from the storage area to a safe place before work starts. 7 Fsgn 40

8 8 Design and Construction of Containers All containers should be designed and constructed to standards suitable for the purpose. They should be robust and provided with well-fitting lids or tops to resist spillage if knocked over. For steel drums BS 814 is suitable, while for freight containers BS 3951: Part 2, or an equivalent standard should be used. For plastic containers of approximately 5 to 10 litres capacity, the general standards in the Approved Code for plastic petrol containers may be used. If glass or other fragile containers are used, the packaging should include protection against impact damage, and may also include absorbent material to help contain the contents if a breakage occurs. Where necessary, containers should be protected against corrosion (for example by painting) and degradation by light (by suitable shading). In addition, the material used in the construction of the container should be compatible with the chemical and physical properties of the liquid to ensure that no interaction occurs which might cause leakage. 9 Small Quantities Cans and other small containers, up to 50 litres total capacity, may be kept in a workroom in a suitably-placed fire-resisting cupboard or bin. Cupboards and bins should be constructed to the following standards: a. Each side, top, floor and lid should be able to satisfy BS 476: Parts 20 and 22 with regard to freedom from collapse and resistance to passage of flame for at least half an hour. b. The internal surface material (and any substrate to which it is bonded) should, if tested to BS 476: Part 6 (fire propagation test) have an index of performance of not more than twelve, and a sub-index or not more than six. c. Junctions between each side, top and floor should be bonded or fire stopped to prevent or retard the passage of flame and hot gases. d. The structure should be robust enough to withstand foreseeable accidental damage. e. If surfaces of the structure are liable to be coated with residues, the structure should allow for removal of the residues without affecting its fire-resistance. f. Each side, top and floor should be supported and fastened to prevent failure of the structure in a fire for at least half an hour. Supports and fastenings should be non-combustible if tested to BS 476: Part 4, or if tested to BS 476: Part 11 should not flame and should give no rise in temperature on either the centre (specimen) or furnace thermocouples. 8 Fsgn 40

9 10 Notices Storerooms, cupboards and bins need to be marked with the yellow hazard triangle symbol Flammable Liquid. If it is not reasonably practical to mark directly on the storage area, then it can be displayed nearby as in Figure 1below; Figure 1 Figure 2 A Hazard Zone warning sign should be displayed at the point of entry to a potentially explosive atmosphere process risk such as where highly flammable liquids are in use or exposed in a defined hazard zone, as in Figure 2 above. The signs are black letters/symbols on a yellow background. No Smoking and No Naked Lights notices may also be appropriate in accordance with the Health & Safety (Safety Signs and Signals) Regulations Firefighting Equipment Firefighting equipment should be provided at readily accessible locations at the storage area; for example at access points to container stacks and at exits of storage buildings. Fire extinguishers should comply with BS EN 3 and be of at least 223B rating; for example a 9 kg Dry Powder extinguisher or a 9 litre Foam. In order to guard against equipment failure, it is preferable at all but very small installations to have extinguishers grouped in pairs. Where necessary on larger sites, hand-held extinguishers should be supplemented by bigger units, such as 50 kg powder extinguishers or mobile foam equipment of 100 litre pre-mix capacity. All equipment should be located where it is readily available to plant operators. Protection against the weather may be required. For storage in buildings, two foam or dry powder extinguishers with a total rating of at least 223B should be provided for stores up to 20,000 litres capacity. For larger stores, two additional extinguishers of the same total rating should be provided. Extinguishers should normally be located at the exits to the store. Alternatively, extinguishers can be selected, sized and located in accordance with BS 5306: Part Emergency Procedures and Training A procedure should be drawn up to deal with fires and leaks. It may be necessary to consider incidents in other parts of the premises or in adjacent premises. Everyone on site should be informed of the hazard from flammable liquids stored there and of the need to keep sources of ignition and heat away from the store. Those handling flammable liquids should also receive specific training in both normal operating procedures and emergency procedures. Periodic re-training will also be necessary. Training should, where appropriate, cover: a. Safe operation of the installation and its associated equipment. b. Use of protective clothing. c. Housekeeping. 9 Fsgn 40

10 d. Reporting of faults and incidents, including minor leaks and spills. e. Emergency procedures, including means of raising the alarm, calling the Fire Service, evacuation procedures, using the appropriate firefighting equipment and controlling spills and leaks. f. Relevant storage recommendations in the risk assessment. 13 Maintenance and Modification Storage areas and buildings, rooms, cupboards and bins used for storage, must be adequately maintained and electrical installations and equipment regularly tested and inspected. The electrical certificate requires annual renewal, in accordance with the Institute of Electrical Engineers (IEE) guidance. Consideration should be given at the planning stage to the hazards that any proposed modifications may cause and a risk assessment carried out before any such work commences. References: Health and Safety Series booklet (HSG51) The Storage of Flammable Liquids in Containers (HSE Books 1998) Further advice: Advice is available either by contacting the relevant department of the District or Borough Council responsible for the administration of the licensing procedure or by contacting: Bedfordshire Fire and Rescue Service Northern Area Office Barkers Lane BEDFORD MK41 9SB Bedfordshire Fire and Rescue Service Southern Area Office Studley Road LUTON LU3 1BB All telephone enquires (01234) Fsgn 40