STORE HAZARDOUS SUBSTANCES SAFELY 37) The new container must also be clearly labelled with the same information and warnings as the original container.
STORE HAZARDOUS SUBSTANCES SAFELY DECANTING INCOMPATIBLES GAS CYLINDERS OXY-ACETYLENE WELDING FLAMMABLE SUBSTANCES
36 STORE HAZARDOUS SUBSTANCES SAFELY
STORE HAZARDOUS SUBSTANCES SAFELY Storing hazardous substances safely is an important part of protecting you and your staff.
DECANTING It’s best to keep your hazardous substances in the containers they are bought in. However, many businesses purchase hazardous substances in drums or large containers and then decant smaller amounts of the substance into other containers for use. While this may seem like a simple task, it needs to be done safely to avoid accidents.
NEVER store hazardous substances in food or drink containers – it’s just too easy for someone else to get confused about what’s in the container – even if it is labelled. Too often people are seriously harmed after accidently drinking hazardous substances stored in drink containers.
CHECKLIST When you are planning to decant a substance from one container to another, keep the following things in mind:
)) Read the safety data sheet and note the hazards of the substance, particularly whether it is flammable, toxic or gives off fumes.
)) Wear the recommended personal protective equipment, for example eye protection, breathing protection, gloves and overalls. Eye wash stations and/or safety showers may be needed in areas where transfers are performed in case substances spill on workers.
)) Work in a well-ventilated area. This will help to prevent you from breathing in high concentrations of possibly poisonous vapours and gases and will also prevent flammable vapours building up, which could ignite causing a fire or explosion.
)) Use only containers the hazardous substance can be stored in safely. Some substances can react dangerously with containers made out of different materials. For example, hydrochloric acid can react with some metals to form explosive hydrogen gas and hydrofluoric acid reacts with glass, so needs to be stored in a durable plastic container. This information is available from the safety data sheet or your hazardous substances supplier.
)) Make sure the new container is clean and doesn’t contain any residues of other substances that may cause a violent reaction.
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)) The new container must also be clearly labelled with the same information and warnings as the original container. All containers holding hazardous substances must be labelled.
)) Note that flammable liquids, such as petrol and solvents, release flammable vapours so you need to avoid sources of ignition when transferring flammable substances (see the list of ignition sources on page 41).
)) Flammable liquids may also generate static electricity that may discharge and ignite the substance so make sure metal or conductive plastic containers are earthed or bonded correctly (see the further information section on page 42).
)) Be prepared for any spill that might occur during the transfer process. Have your spill kit ready to clean up any spill. More information about spill kits can be found in the Emergency Preparation section, page 43.
INCOMPATIBLES Not all hazardous substances can be stored together safely. Different types of substances can cause a fire or explosion if they come into contact with each other. These substances are often described as “incompatible” and it’s important that they are stored separately to prevent the substances from mixing if a leak or spill were to occur. The safety data sheet for a hazardous substance will tell you which substances and materials it should be kept away from, but the box below provides some general guidance.
INCOMPATIBLE SUBSTANCES – GENERAL GUIDANCE Hazardous substance type:
Keep away from:
Flammable gases (class 2.1.1)
Flammable aerosols (class 2.1.2); flammable liquids (class 3); class 4 substances; oxidising substances; organic peroxides (class 5).
Flammable liquids (class 3)
Flammable gases and aerosols (class 2); class 4 substances; oxidising substances; organic peroxides (class 5).
Oxidising substances (class 5.1)
All other types of hazardous substances (including organic peroxides).
Organic peroxides (class 5.2)
All other types of hazardous substances (including oxidisers).
38 STORE HAZARDOUS SUBSTANCES SAFELY
The most important thing to remember is to
Keep your FLAMMABLES (such as petrol, turps, solvent paints and thinners)
Away from OXIDISERS (such as hydrogen peroxide, pool chemicals).
STORE ONLY WHAT YOU NEED Keep the amount of hazardous substances you store to a minimum. This will make it easier to manage what you have and may reduce your compliance needs and costs.
SIGNS Depending on the types and amounts of hazardous substances you have, you may need signs to warn people that hazardous substances are present. The signs should tell people about the hazards of the substances and the precautions and emergency actions to take. See Hazardous substance information, page 23.
BE PREPARED FOR A SPILL Your workplace needs measures in place to control any hazardous substance spill or leak. For small spills, a spill kit might be sufficient to contain and clean up the spill. If you have large amounts of hazardous substances you are likely to need secondary containment (also known as bunding). See Emergency preparation, page 43.
PUT A LID ON IT! Keep lids on your hazardous substance containers to keep the vapours inside. This stops the fumes and vapours from contaminating the air that you and your staff breathe. Keeping the lid firmly on the container also reduces the chance of a spill if the container were to fall over.
GAS CYLINDERS If your business stores gas cylinders, it’s important that you handle and store them carefully to make sure that the cylinder isn’t damaged. If a cylinder is weakened, the contents of the cylinder can explode. Empty or near-empty cylinders should also be handled carefully.
STORE HAZARDOUS SUBSTANCES SAFELY 39
Wherever possible, cylinders should be stored, handled and used in an upright way, unless they have been specifically designed for horizontal use.
TYPES OF CYLINDERS
dd Most general purpose LPG cylinders are designed for upright use. dd Vehicle and forklift cylinders are designed for use horizontally although forklift cylinders may normally be handled and stored vertically.
dd Self-contained breathing apparatus (SCBA) or self-contained underwater breathing apparatus (SCUBA) cylinders may normally be handled and stored horizontally.
dd Acetylene cylinders contain acetone as a solvent for the gas and must be used
upright to avoid the possibility of acetone being discharged with the acetylene. If transported horizontally, they must be stood upright for at least one hour before use.
TESTING OF GAS CYLINDERS Gas cylinders should be tested to ensure that they remain safe to use. Poorly maintained gas cylinders may leak, which could cause staff to become exposed to hazardous substances or could potentially cause an explosion.
CHECKLIST STORE ANY GAS CYLINDER IN A LOCATION THAT: )) is suitable for the type and quantity stored )) is secure )) is well ventilated, and )) has an emergency response plan and hazardous substance warning signs in place, if required.
IF THE GAS IS FLAMMABLE, ALSO STORE YOUR CYLINDER IN A LOCATION THAT: )) is of fire resistant construction )) is suitably separated from potential sources of ignition (also required if the gas is an oxidiser), and
)) has fire extinguishers available (also required if the gas is an oxidiser). In addition to the above, it’s good practice for the cylinders to be protected from the weather.
40 STORE HAZARDOUS SUBSTANCES SAFELY
OXY-ACETYLENE WELDING Oxy-acetylene welding equipment is one of the few exceptions where two incompatible hazardous substances (acetylene, a flammable gas, and oxygen, an oxidiser) are permitted to be used together. Because of the incompatibility of these substances, it’s vitally important to make sure the gas cylinders are correctly maintained. If your workplace keeps spare acetylene and oxygen cylinders, they must be stored separately in order to minimise the potential for harm if an incident involving one set of cylinders occurs. Welding activities are capable of causing workplace fires, so it’s important to take all necessary safety precautions when welding. Oxy-acetylene welding kits must have flashback arrestors fitted – if the item being welded ignites, the flashback arrestors stop the flame from travelling down the lines to the cylinders. WorkSafe have a page on their website about health and safety in welding. Search for “welding” on WorkSafe’s homepage www.worksafe.govt.nz or visit www.hazardoussubstances.govt.nz for a direct link to this page.
FLAMMABLE SUBSTANCES STORAGE CABINETS Smaller amounts of flammable substances should be stored in an approved metal cabinet. The cabinet must conform to the standard set out in AS1940: The storage and handling of flammable and combustible liquids – ask your safety supplier for help. You can store up to 250 litres of hazardous substances in an approved cabinet as long as each container is less than 20 litres in size. If you have very large amounts of hazardous substances, you may need to keep them in a storage depot or separate building. Contact a test certifier or a safety consultant to find out what you need in place to safely store your substances.
FLAMMABLE VAPOUR Flammable substances release vapour, which can cause an explosion if accidentally ignited. If you are using or storing flammable gases or liquids you will need adequate ventilation to prevent the build-up of flammable gases or vapours.
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Ignition Ignition sources must be removed where flammable substances are used and stored. A table of common ignition sources is listed below.
Examples of ignition sources: Type of ignition source
dd Welding flames, gas heaters, pilot lights
dd Welding arcs, starters for fluorescent lighting, electric
motors, electrical equipment like power points, cigarette lighters, switches, telephones
dd Static electricity, including from friction sources dd Lightning dd Drilling, grinding, scraping of metal over concrete Heat
dd Hot surfaces including light bulbs, ovens, radiators or
heaters, flue pipes, vehicle engines and exhaust systems (for example, forklifts) pumps and generators
dd Exothermic chemical reactions that generate heat This table was taken from Safe Work Australia’s code of practice: Managing risks of Hazardous Chemicals in the Workplace.
Hazardous atmosphere zones A hazardous atmosphere zone is a specific control that identifies an area where flammable vapours may be present around a place where flammable substances are used or stored. In the zone, special precautions need to be taken to prevent ignition. The dimensions of each zone depend on factors which include the types of hazardous substances and the quality of the ventilation in place. Within each zone, you need to consider whether potential ignition sources exist. Electrical equipment must be suitable for the zone or kept away from areas where vapour might build up, such as dangerous goods stores and workrooms. Get advice and, if necessary, an electrical certificate from a registered electrical inspector if you aren’t sure whether your electrical equipment is intrinsically safe or is at a safe distance from a hazardous atmosphere zone.
42 STORE HAZARDOUS SUBSTANCES SAFELY
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Generally, a hazardous atmosphere zone extends out three metres from a dangerous goods cabinet or store and one metre above. No ignition sources should be within that zone. If you must have electrical equipment in that area it must be intrinsically safe.
Controlled zones A controlled zone is a defined area where flammable or oxidising substances are located. Within that area, the adverse effects of the hazardous substances must be reduced or prevented so that beyond the controlled zone the public is provided with reasonable protection from those adverse effects. Every controlled zone is different and will depend on a variety of factors, including:
dd the amount of flammable or oxidising substances stored at your workplace dd the classification of those substances dd the type of storage – whether the hazardous substances are stored in tanks, drums, packages or cylinders and whether they are stored inside or outside, and
dd the construction of the buildings and the neighbouring environment. Generally, you only need to establish a controlled zone if you need a location test certificate. Talk to your test certifier if you are unsure about what to do. See Test certificates, page 51.
GET A LOCATION TEST CERTIFICATE, IF REQUIRED If you have flammable or oxidising substances at your workplace you may need a location test certificate to certify that the hazardous substances are being stored safely, according to the rules. See Test certificates, page 51.
FURTHER INFORMATION INCOMPATIBLE SUBSTANCES The code of practice Hazardous Substances Storage (HSNOCOP 16) is available to help you work out which hazardous substances are incompatible with each other. This code is available free from a HSNO enforcement officer or for purchase from Responsible Care New Zealand, www.responsiblecarenz.com. A copy of the code is available for viewing at WorkSafe’s office in Wellington.
BONDING CONTAINERS (STATIC ELECTRICITY) See the Canadian Centre for Occupational Health and Safety – www.ccohs.ca/oshanswers/prevention/flammable_static.html