Flammable substances such as solvents and fuels are present in many workplaces, but they can cause devastating fires and explosions if handled incorrectly.
This can be avoided by properly assessing the risks and adopting precautions such as safe storage.
The incorrect storage or poor management of liquids can have far reaching consequences for your business and the environment and although there are various Storage Regulations in place it’s all too easy to forget that all liquids pose a potential threat to health, safety and the environment if not properly stored and handled. Remember YOU are responsible for all the liquids on your site and YOU can be prosecuted for a pollution incident that originates on your site even if it was caused by an act of vandalism.
It’s relatively straight forward to ensure that you are protected by using products specifically designed for the task, such rotationally moulded polyethylene spill pallets for indoor applications or bunded drum, FM approved flammable cabinets and IBC stores with fully seam welded sumps for secure outdoor use. The following information will help in determining the correct system to suit your specific requirements and when used in conjunction with other measures including good housekeeping, will substantially reduce the risk of an incident.
As a starting point the following questions will generate the information required to help you ensure you store products correctly and safely.
• What are the liquids?
• Is there a fire, explosion or vapour release risk associated with any of the liquids?
• Is there a requirement to store any of the liquids separately?
• How many litres of each product do you want to store?
• Are you looking to bulk store, or use drums & or IBC’s?
• Will the liquid be stored indoors or out?
• If indoors are there any access issues with regard to the location?
• If outdoors are there surface water drains or a water course in the vicinity?
• How will the liquids be delivered to site?
• How will they be moved around the site?
The MSDS (Material Safety Data Sheet) for the liquids you use will provide much of the detail required to answer questions 1 to 3, you should of course talk to the product manufacturer for advice on issues such as segregation of liquids, possible explosion risk and vapour release hazards.
Determining the amounts (litres) of product, in what types of container (205ltr drums, 1000ltr IBC, bulk tanks etc.) you require to hold on site (don’t forget to allow for empty containers which are likely to have residues in them and must therefore still be stored correctly) is fundamental to ensuring you don’t end up with product stored in a way that will lead to an incident.
You must consider the location of the storage area with great care to minimise the risks of damage to the environment, the health and safety of your employees and the public. It must be located somewhere that if there is a leak or spill, you will not pollute the air, land, surface or ground waters.
It goes without saying that your storage containers (bunded stores, spill pallets etc.) must be designed with environmental protection in mind. This means that the bund and any storage units or spill pallets must comply with your local regulations and you must check that that they are made of a material that is compatible with the liquid you are storing. Don’t forget to consider how you protect the drums or IBC’s when they are being moved around the site, bunded trolleys or mobile spill pallets are ideal but remember to properly secure them onto the trolley or pallet before setting off.
If your bund is unprotected rainwater will collect in it and reduce its capacity, you must always check the contents before disposing of it to ensure you don’t cause a pollution incident by discharging contaminated water.
It is against the law to discharge anything into the sewer that could harm or interfere with the treatment or disposal of the sewer contents. If you have any emergency safety showers on your site, ensure that any used water after an incident is disposed of in the appropriate manor as it may be contaminated. Please check your local bylaws regarding the disposal of contaminated liquids
You must dispose of all contaminated water as hazardous/special waste.
Don’t forget areas where you have smaller amounts of chemicals such as laboratories, test rigs, workshops or vehicles. The same rules apply but you may only require a laboratory cabinet (Flammable liquids must be held in an appropriate fire-proof steel cabinet) to store the liquids in.
Remember to consider segregation issues when storing different liquids together and ensure the cabinet is secured to the floor and/or wall to prevent it toppling over, avoid the temptation to store chemicals directly on the floor, even on a temporary basis and always avoid storing above eye-height, or on top of cupboards or cabinets and wear/use PPE (Personal Protective Equipment) as appropriate at all times.
Keep an inventory of the liquids you have on site and ensure it is kept somewhere it can be accessed easily out of hours for use by spill responders or outside agencies.
It’s important that your staff is trained and know how to deal with any spills that may occur and that you have a pollution incident response procedure in place. Ensure that you have spill kits, containment equipment and drain sealing products suitable for the type and quantity of liquids you store and use on site. Locate response equipment close too and remote from any area that poses a risk and remember to ensure the location is marked on your site plan (again available to staff or outside agencies) and that they are highly visible and not hidden behind anything that will restrict access.
Remember if you cause pollution you could be fined and prosecuted
The safe storage of flammable liquids in process areas, workrooms, laboratories and similar working areas requires additional careful and informed consideration. Best practices and regulations require risks from the indoor storage of Dangerous Substances to be controlled by elimination or by reducing the quantities of such substances in the workplace to a minimum and providing mitigation to protect against foreseeable incidents.
There are 3 elements required for a fire to start:
HEAT — OXYGEN — FUEL
If you eliminate any one of these elements, you eliminate the fire
HEAT can be any ignition source which generates heat, such as a mechanical spark, static electricity, a naked flame such as from welding equipment etc.
OXYGEN is all around us
FUEL can be any flammable or combustible liquid, remember flammable vapours are a significant hazard too.
Store flammable liquids in a separate area in purpose made bins or cupboards that are compliant with the regulations and when dispensing, ensure there is good ventilation and no sources of ignition. Always keep containers closed when not in use, whenever possible use safety containers with self-closing lids and flame arresters and always have the appropriate spill kit available too.
Flammable dust in the atmosphere can if ignited, explode violently, so if you handle flammable dusts you need to remember to keep your plant dust-tight and regularly clean the area to keep it dust free. Don’t forget to vacuum any spills as they occur, remember you will need intrinsically safe equipment.
Many types of packaging material (plastic foam, polyester wadding, textiles etc) give off dense black smoke when they burn so remember not to store them close to heaters or electrical equipment which could act as an ignition source.
Gases are often stored at very high pressure and any uncontrolled release can fill a large area quickly, this is particularly true of liquefied gases such as LPG. You should store cylinders in a designated area in purpose built stores and always restrain the cylinders and try to protect the valves from potential impact damage.
Materials that ordinarily burn slowly will burn vigorously in an oxygen rich atmosphere so in the same way that you protect flammable gases you must store any oxygen in a secure and controlled manor and over and above that, remember never use oxygen instead of compressed air, never use oxygen to sweeten the air in a working area or confined space and never use grease or oil on equipment containing oxygen as they can self-ignite.
Some products have chemicals such as organic peroxides as part of their composition which can explode if not stored and handled correctly. Whilst other substances can react with incompatible materials or contaminants in an explosive manor, for example oxidizing chemicals can cause flammable materials to ignite and some substances such as sodium react violently and can ignite when they come into contact with water. Storage and process temperatures should be controlled in line with recommended levels (check the MSDS or contact manufacturers help desk) to prevent dangerous decomposition or reactions.
The risk of explosion and or fire from flammable gases, mists, vapours or even combustible dust is ever present in a great many working environments. Once the substance mixes with the air all it needs is a source of ignition to cause an explosion. It goes without saying that this scenario can lead to a loss of life and or serious injuries as well as significant damage to property.
Preventing the releases of dangerous substances, which can create explosive atmospheres, and preventing sources of ignition are critical to reducing the risk of an incident and with the onus for ensuring your products are stored correctly and your handling and use procedures are safe and fully compliant being your responsibility, it is key that you fully understand the hazards associated with those products. Information from Material Safety Data Sheets and manufacturer’s help desks are invaluable sources of accurate facts and manufactures of safety equipment such as fire rated storage units, earthing wires, or flammable liquid transfer containers will of course offer specific advice too. Please don’t forget to consult with your local authority fire brigade and your insurance provider.
Some questions worth considering when working with flammable substances:
• Is there good natural air movement in and around where the flammable substances are stored and used? If not you may have to consider mechanical air changes. Good ventilation will mean that any vapours given off from a spill, leak, or release will be rapidly dispersed.
• Have all the obvious ignition sources been removed from the storage and handling areas? You need to think outside the box as an ignition source can be very varied, sparks from electrical equipment, welding or cutting tools, hot surfaces, open flames, static charge etc.An explosion can be caused by the simple action of decanting a flammable liquid from one container to another if they have not been earthed
• Are your flammable substances kept in the correct type of container? Does it need to be fire rated? Or if there is a spill will it be contained and prevented from spreading? Depending on the quantity of product involved and the separation distance you may need a fire rated storage unit.
• Can you replace a flammable substance for a less flammable one? Or can you eliminate it from the process completely? Processes and products evolve, check with your supplier(s) and see if they can help you redesign yours to make it safer.
• Are your flammable substances stored and used in a different area to other processes? By separating them you will lessen the risk of an incident and improve workplace safety.
For practical purposes where flammable liquids are required in a process, there is likely to be a need for a limited quantity to be stored and available in the workplace. It is the responsibility of the employer/duty holder when carrying out their risk assessment to justify the need to store any particular quantity of flammable liquid within the work room/working area. However, the guiding principle is that only the minimum quantity needed for frequently occurring activities or an amount required for use during half a day or one shift should be present in the work room/working area. Actual quantities will depend on the work activity and also the arrangements for controlling the fire risks.
When not in use, containers of flammable liquids needed for ongoing work should be kept closed and stored in suitable fire resistant cabinets or bins which are also designed to retain spills. They should be located in designated areas that are where possible away from the processing area don’t interfere with any escape route from the working area.
Flammable liquids should be stored separately from other dangerous substances that may enhance the risk of fire or compromise the integrity of the container or cabinet/bin it’s stored in; for example, oxidizers and corrosive materials should be stored separately from each other. Remember other dangerous substances may also be flammable in their own right however, it is still inappropriate to store these in the same cabinet/bin with flammable liquids.
The general recommendation for maximum allowable maximum quantities that are stored in cabinets / bins are no more than 40ltr for extremely flammable, highly flammable and those flammable liquids with a flashpoint below 37ºC (Class I) and no more than 200ltr for other flammable liquids (Class II and III)
In the event of an incident the objective is to ensure that people can safely escape from the working area and in this context, the purpose of storing Dangerous Substances in the appropriate cabinets/bins is to provide a physical barrier to delay the involvement of the stored materials in a fire and provide sufficient time for people’s safe evacuation and the duty holder’s immediate emergency procedures supporting this to be implemented.
It is the responsibility of the employer/duty holder to ensure that cabinets/bins meet the minimum legal requirements. Equally, the use of cabinets/bins with enhanced fire performance should not be seen as a substitute for the provision of a dedicated store room(s) and outdoor storage areas for the safe keeping of containers which are nominally empty or are not needed for current work.
It’s important not to overlook any aspect associated with the safe handling of flammable liquids such as static discharge during filling/decanting, combustion due to excessive heat build-up, potential ignition sources such as a spark from a tool or electrical component and pressure build-up in a container.
Please remember to consult with your local fire department and insurance provider as they will have valuable input that could save you time and money going forward.
An outside pair of eyes will often see things that have become commonplace to you, so you might want to consider using the services of an outside company to assess/review your site.
Alan N Wild
Jesbra Group (Pty) Ltd T/A
Spill Doctors SA
Tel: 00 27 10 003 6060
Cell: 0027 82 573 1959
Acknowledgment – Andrew Lawrence of Empteezy