Introduction
Explosion hazards can be hidden in everyday work tasks, yet they carry the potential for catastrophic harm to people, assets, and a company’s reputation. In the UK, the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) place a legal duty on employers to assess and control these risks. A key part of this process is establishing a basis of safety - a clear strategy for preventing or mitigating explosions in your operations.
Understanding the Legal Framework
DSEAR - the Dangerous Substances and Explosive Atmospheres Regulations - sets out the legal responsibilities for UK businesses handling flammable or explosive substances. Employers must identify hazardous materials, assess the likelihood of explosive atmospheres, evaluate possible ignition sources, and implement effective controls. Substances requiring assessment include raw materials, products, and by-products such as dusts, powders, gases, vapours, and flammable liquids.
Compliance goes beyond checking a legal box: it reduces the risk of devastating fires or explosions. To demonstrate this, businesses must document their findings in a suitable risk assessment. This record captures the properties of substances, outlines safe operating limits, and provides evidence that the business has taken systematic, proactive steps to protect its workforce and operations.
The Basis of Safety
A basis of safety is the defined method by which a business prevents or mitigates fires or explosions. Regulation 6 of DSEAR states that where employers cannot eliminate the risk, they should:
Control the Risks – reduce the quantity of dangerous substances, avoid/minimise/control the release, prevent the formation of a flammable atmosphere and control any ignition sources.
Mitigate the Effects of Fire or Explosion – reduce the number of employees exposed, explosion/fire propagation, explosion venting, suppression or containment systems.
The chosen basis must be justified with reliable data and supported by testing. Importantly, it should not be a “set and forget” measure, any basis of safety must be
systematic, documented, and reviewed regularly to remain effective as processes, substances, or regulations evolve.
Role of Testing and Assessment
Testing is critical to understanding how substances behave and to defining a robust basis of safety. Accredited providers should offer a range of specialist tests, including:
- Dust explosibility testing (Kst, Pmax): measures explosion severity and maximum pressure rise.
- Minimum Ignition Energy (MIE): determines the smallest spark or discharge that can ignite the substance.
- Limiting Oxygen Concentration (LOC): identifies the oxygen level below which an explosion cannot occur.
- Electrostatic charge testing: assesses the likelihood of dangerous sparks from material handling or equipment.
These results feed directly into risk assessments, helping businesses establish safe operating parameters and select appropriate control measures. Independent, accredited testing not only builds confidence in safety systems but also provides credible evidence for regulators, insurers, and stakeholders that risks are being managed responsibly.
Conclusion
Explosion risks may not always be obvious, but their consequences are too serious to ignore. By complying with DSEAR, businesses not only meet legal obligations but also protect their people, assets, and reputation. Establishing a clear basis of safety, supported by accurate testing and independent expertise, ensures that controls are effective, justifiable, and resilient over time. Ultimately, managing explosion hazards is about more than ticking boxes, it is about creating a culture of safety that gives your business the confidence to operate securely and sustainably.
