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Storing Hazardous Chemicals: The Key Considerations


Using chemicals or other hazardous substances at work can put people’s health at risk. The law requires employers to control exposure to hazardous substances to prevent ill health.

Control measures must ensure employees and others who may be exposed are protected and to that end The Control of Substances Hazardous to Health Regulations 2002 (COSHH) (as amended) and the support leaflet COSHH: A brief guide to the Regulations explain what you need to know.

Improperly stored hazardous substances can be highly dangerous and potentially cause a serious accident. A safe storage location for your hazardous substances should primarily limit the exposure of workers and others to the risks associated with the product; and protect them from the hazardous effects that could result from an accidental spillage or chemical reaction. It is especially important that you never store hazardous substances in the vicinity of food or drinks.

When storing hazardous substances in the workplace:

  1. Read the safety data sheet (SDS) and the containers label fully and follow the recommended storage information.
  2. Make sure copies of the SDS are readily available to staff and attending emergency services.
  3. Ensure the storage area is protected against unauthorised access or use.
  4. Only keep minimal amounts of each product onsite and ensure that everything is clearly and correctly labelled and that the labels are intact and legible.
  5. Ensure that containers are protected from fluctuations in temperature, exposed to the sun, excessive heat or sources of ignition.
  6. Provide the correct levels of ventilation.
  1. If the storage area requires an electrical supply for lighting, heating, refrigeration etc. and the goods are flammable or explosive; ensure the electrics are fully compatible (ATEX rated).
  1. Make sure the appropriate warning signage is used and visible.
  2. Check all products for compatibility issues and segregate as appropriate.
  3. Keep on top of housekeeping and ensure that the condition of the containers is regularly checked and that the storage unit is kept clean and tidy.
  4. Do not store liquids above solids to avoid contamination in the event of a leak.
  5. If possible use additional drip trays to contain leaks and drips in a defined area. This is especially important if the substance is corrosive.
  6. Ensure the appropriate spill response kits are kept in the local area and remote from it.
  7. Ensure your response teams are fully aware of the risks associated with the substances stored and are regularly trained.

European Directive 99/92/EC (ATEX 137 or the ATEX Workplace Directive) refers to minimum requirements for improving the health and safety protection of workers at risk from explosive atmospheres. In the UK the directive was implemented under the Dangerous Substances and Explosive Atmospheres Regulations 2002 which place a duty on employers and the self-employed to protect people from these risks to their safety in the workplace, and to members of the public who may be put at risk by work activity.

Dangerous substances are any substances used or present at work that could if not properly controlled, cause harm to people as a result of a fire or explosion or corrosion of metal. They can be found in nearly all workplaces and include such things as solvents, paints, varnishes, flammable gases, such as liquid petroleum gas (LPG), dust from machining and sanding operations, dust from foodstuffs, pressurised gases and substances corrosive to metal.

DSEAR requires employers to:

  • Find out what dangerous substances are in their workplace and what the risks are.
  • Put control measures in place to either remove those risks or, where this is not possible, control them.
  • Put controls in place to reduce the effects of any incidents involving dangerous substances.
  • Prepare plans and procedures to deal with accidents, incidents and emergencies involving dangerous substances.
  • Make sure employees are properly informed about and trained to control or deal with the risks from the dangerous substances.
  • Identify and classify areas of the workplace where explosive atmospheres may occur and avoid ignition sources (from unprotected equipment, for example) in those areas.

The regulation is supported by an Approved Code of Practice (ACOP) and guidance document which is issued by the Health & Safety Executive and provide really useful advice on how to comply with the regulation; covering: design, storage, control and safe maintenance.

Following the guidance is not a legal requirement or compulsory, unless specifically stated; and you are free to take other action, but having said that if you do read and follow the guidance provided in the ACOP you will normally be doing enough to comply with the law.

It is worth noting that health and safety inspectors seeking to secure compliance with the law and may refer to this guidance.
Some questions worth considering:

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 even be caused by the simple action of decanting a flammable liquid from one container to another if they have not been earthed.
Are your substances kept in the correct type of storage unit?

Check the distance from the unit or proposed site of the unit to occupied buildings, boundaries, process units, flammable liquid storage tanks and or sources of ignition.
Does it need to be fire rated?

If you can’t meet the separation distance relevant to the volume of liquid you are storing you will need to use a fire rated unit.
If there is a spill will it be contained and prevented from spreading?

Consider what will happen if the liquid spills out with the bunded storage unit.

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 hazardous substances in the appropriate storage unit is to provide a physical barrier to delay the involvement of the stored liquids in a fire and provide sufficient time for people’s safe evacuation and the immediate implementation of emergency procedures.


It’s important not to overlook any aspect associated with the safe handling of hazardous 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 insurance provider and local authority fire brigade as they will have valuable insight that could save you time and money going forward. Also you might want to consider the services of an outside company to assess/review your site; as an outside pair of eyes will often see things that have become commonplace to you.

Emtez is an ISO 9001, ISO 14001 & ISO 45001 accredited company with more than 37 years’ experience of manufacturing spill containment and spill response products and we are happy to offer a free of charge audit and without onus site assessment to anyone responding to this article quoting HAZ2020.
Features and benefits of Emtez hazardous substances storage units:

Materials/protective coatings to suit liquid stored Protects against corrosion/degradation
Sump holds 25% of the combined total of all the containers stored Ensures compliance with UK regulations relating to sump capacities
Fully welded leak tested sump Spilt or leaking liquid is fully contained
Manufactured in the UK in our own factory Can be customised to suit your specific requirements without compromising on quality or compliance and a wide range of optional extras are available too.
No set-up required* Ready for use as soon as the unit has been positioned

*Unless certain options such as electrics have been specified