3 Key Isolation Controls for Managing Hazardous Chemicals

Isolating your hazardous chemicals from workers and incompatible substances is an important risk control measure and critical to worksite safety. While the use of control measures, such as administrative controls and personal protective equipment, can assist in minimising the harm caused by hazardous substances, it’s essential to consider how to isolate chemicals and dangerous goods in your workplace to ensure optimum health and safety.

In this post, we outline 3 different isolation control methods which can help you meet the requirements of the WHS Regulations to minimise chemical hazards with suitable risk controls.

REMEMBER: The Hierarchy of Control lists 5 control measures to improve safety for your operations. To learn more about isolation controls, administrative controls and personal protective equipment, read our popular post that explains the process of risk management.

1. Distance and Barriers

Segregating chemicals into hazard classes — and then separating them by distances of at least 3-5 metres from incompatible substances — is a simple isolation control.

This control measure is required by the Australian Standards as well as the ADG Code.

Dangerous goods such as toxic, flammable, corrosive, oxidising substances, organic peroxides and compressed gases all have minimum separation distances between the chemical class and incompatible substances. The isolation also continues to separation from site boundaries and protected places.

But if your worksite has limited space, it may be appropriate (upon a risk assessment) to separate incompatible chemicals 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 Australian Standard will provide information on the barrier walls/screens including:

• 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 only, we recommend having the appropriate spill bunding in place under pallets or containers. This will assist in providing spill control to reduce the likelihood of substances coming into contact with each other.

You should also ensure that different hazard classes are not in contact with the same drainage system, as this will create hazards.

2. Indoor Safety Cabinets

When chemicals must be stored indoors, you can use indoor safety cabinets which are designed for the particular class of goods that you’re storing. For example, flammable liquids must be stored in a Class 3 safety cabinet which will provide the appropriate controls to minimise the risk of flammable liquid fires and other associated hazards.

However, even with the use of dedicated safety cabinets, you will have to install these in a location that adheres to the correct segregation distances for incompatible substances.

By storing chemicals in dedicated storage – with provisions such as vapour control, spill containment and ventilation – you can ensure chemical safety.

Here are some general tips for indoor chemical storage:

• Choose a safety cabinet purpose-built for the hazard class of the chemicals, ie. flammable liquids, oxidising agents, corrosives. This is an effective control measure when storing dangerous goods and hazardous chemicals in the indoor environment as they are constructed to provide maximum protection for each chemical class.
• Don’t store mixed classes of hazardous chemicals in the same cabinet unless the cabinet is designed for this purpose, ie. a corrosives cabinet with internal isolation areas for acids and bases.
• Don’t interchange indoor and outdoor chemical safety cabinets, as these are each built to meet the Australian Standards, which offers some differences between indoor and outdoor chemical storage.
• Ensure the cabinet has a liquid tight spill sump.
• Don’t load the safety cabinet past its capacity, ie. 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, ie. some older flammable liquids cabinets do not have self-closing doors and therefore are no longer compliant.
• Use compliant warning placards and labels.

Safety cabinets offer built-in spill containment, self-closing doors and other controls which prevents incompatible substances from making contact.

REMEMBER: You will need a Register of Hazardous Chemicals including the Safety Data Sheets (SDSs) for each of the chemicals stored. A document box attached to the door of your cabinet or store is an ideal chemical safety document solution.

3. Outdoor Chemical Stores

Installing chemical storage containers 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. Compliant outdoor chemical storage, such as the Storemasta range, will also be designed and manufactured for the environmental conditions outdoors. This will include features such as natural ventilation to aid the cooling of the container, cambered roofs to ensure adequate rain run-off and cyclone-rated construction to provide protection from severe weather.

Outdoor chemical storage must control the risks posed by the chemicals and the outdoor environment.

Outdoor chemical 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). The Australian Standard for your dangerous goods class will detail the required distances dependant on your class, packing group and chemical quantity.

You’ll also need to consider how you can install a safety shower and eyewash station if applicable to the hazard class.

IMPORTANT: AS4332 — 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”.

How to Isolate Chemicals

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 measures. We encourage you to access your copy of our eBook How to manage the risk of Hazardous Chemicals in the workplace. Get your copy for free today and learn the essential steps in the risk assessment process.