Isolating your hazardous chemicals from workers and incompatible substances is an important risk control measure and critical to worksite safety. In this blog we outline three different isolation controls which can help you meet the requirements of the WHS Regulations to minimise chemical hazards with suitable risk controls.
1. Distance and barriers
Segregating chemicals into hazard classes and then separating them by distances of at least 3-5 metres is a simple isolation control, and required by a number of Australian Safety Standards as well as the ADG Code. Toxic, flammable, corrosive, and oxidising substances, plus organic peroxides and compressed gases all have minimum separation distances between the chemical and incompatible substances, site boundaries, and protected places.
But if your worksite has limited space, for some chemicals it is appropriate to separate them using impervious barriers and screen walls. If you are considering barrier walls or screens you should always check the Australian Standard relevant to the hazard class of the chemicals being stored. The standard will detail:
- Minimum height (plus other technical specifications).
- Suitable and unsuitable construction materials.
- Nature of ‘impervious’ ie, impervious to vapours, liquids etc
When separating chemicals by distance we recommend having spill trays or bunding in place under pallets or containers. You should also ensure that different hazard classes are not in contact with the same drainage system.
2. Indoor safety cabinets and store rooms
When chemicals must be stored indoors you can use indoor safety cabinets or a dedicated store room as isolation controls. Cabinets and store rooms keep chemicals out of work areas, and reduce the likelihood of dangerous substances being stolen or misused by untrained workers and visitors.
Here are some general tips for both setups:
Indoor safety cabinets
- Choose a safety cabinet purpose-built for the hazard class of the chemicals. Eg, flammable liquids, oxidising agents, corrosives.
- Don’t store mixed classes of hazardous chemicals in the same cabinet unless the cabinet is designed for this purpose. Eg, a corrosives cabinet with internal isolation areas for acids and bases.
- Don’t interchange indoor and outdoor chemical safety cabinets. Eg, don’t bring an outdoor cabinet inside, or use an indoor cabinet outside. Doing so may negate compliance.
- Ensure the cabinet has a liquid tight spill sump.
- Don’t load the safety cabinet past its capacity Eg, toxic chemicals have restrictions on the total amount that can be stored in the same cabinet.
- Ensure that older cabinets are in perfect working order and meet the requirements of Australian Standards. Eg, some older flammable liquids cabinets do not have self-closing doors and are no longer compliant.
- Use compliant warning placards and labels.
Chemical store rooms
- Ensure the storeroom is fully lockable and access to the immediate area is restricted.
- Make sure entry doors open outwards with proper signage and warning placards.
- Don’t store any chemicals above eye-level (and this should be based on the shortest worker rather than an estimate).
- Don’t store hazardous liquids above other chemicals, materials or substances.
- If your chemical store room has a sink or bench tops don’t leave chemicals out, or under the sink.
- If you keep equipment or tools on shelving above the chemicals, do not climb on the shelves to reach these items. Have a stool or ladder available.
- Use lipped shelving or rails so that bottles and chemical containers don’t roll or fall off the shelves.
- Depending on the size of the store room you may require a safety shower and eyewash inside. Could a worker reach an emergency decontamination station within 10 seconds of injury?
REMEMBER: You will need a Register of Hazardous Chemicals including the Safety Data Sheets (SDSs) for each of the chemicals on-hand. A document box attached to the the store room door or exterior of your safety cabinet is ideal.
3. Outdoor chemical stores
Installing dedicated chemical stores that match the hazard class of the substances you are carrying is an excellent way of restricting access to highly flammable, volatile or reactive substances. An outdoor chemical store is recommended for some hazard classes and most especially for any compressed gases stored in cylinders. Outdoor storage can be beneficial because:
- Leaked gases, fumes, and vapours can dissipate more easily through natural ventilation.
- Flammable and reactive chemicals can be located away from buildings and combustible materials.
- General access to the chemical stores and surrounding areas can be prohibited.
When choosing the location for your chemical store you will need to consider the distance of the store from boundary fences, ignition sources and industrial heat, vegetation, combustible materials, waste stations, air-conditioning ducting, buildings (windows, doors, entrances). You’ll also need to consider how you can install a safety shower and eyewash station if applicable to the hazard class.
IMPORTANT: AS4332:2004 — The storage and handling of gases in cylinders recommends that gas cylinder stores be located outside — “the indoor storage of gas cylinders shall be avoided wherever possible”.
This blog has introduced three important isolation controls to help you manage your hazard chemicals, but we always recommend conducting a proper risk assessment before implementing any chemical control. We encourage you to download our free eBook How to manage the risk of Hazardous Chemicals in the workplace to learn the essential steps in the risk assessment process. Download and read it today by clicking on the image below: