Managing Health and Safety Risks of Harmful Gas Vapours – Part 1

Managing Health and Safety Risks of Harmful Gas Vapours – Part 1

Where chemicals are used or produced in industry, the management of substances hazardous to health are critical to ensure the safety and well-being of employees, on-site contractors, visitors, and the surrounding environment and public. Whilst the headlines and sites regulated by the Control of Major Accident Hazards Regulations 2015 (COMAH) often focus on major risks and incidents, across the UK, smaller scale leaks causing injury (sometimes devastating long term injury) are common.

Finch Consulting is regularly asked to report following failures in equipment that was intended to control escapes of gas and chemical liquids. This experience underscores the need for effective measures to manage the hazards and mitigate the risks associated with leaks of any harmful substances whether or not they emanate from businesses subject to the higher levels of control imposed by COMAH.

The Issue and the Law

The 1984 Bhopal gas tragedy in India provides an extreme example of what can happen when leaks are not effectively managed. A leak of methyl isocyanate from a pesticide plant caused an estimated 558,125 injuries of which approximately 3,900 were severely and permanently disabling. Estimates have suggested 8,000 died within 2 weeks of the leak, and a further 8,000 died subsequently, from gas-related disease.

The 1976 Seveso disaster in Italy impacted thousands through the inadvertent release of tetrachlorodibenzo-p-dioxins (a carcinogen which can cause reproductive, immune, and developmental issues and serious skin conditions) and led to an EU Directive which Great Britain implemented through COMAH.

The HSE recently released a safety notice following an incident in the UK, regarding the hazard created by a gasoline overfill of a carbon adsorption vapour recovery unit (VRU).  The process control system failed and, because the overfill prevention system was not independent, this too failed. The hazard highlighted by this alert included fire and explosion, with the consequential risk of severe injuries and fatalities.

COMAH regulates sites which manufacture or store dangerous chemicals and explosives in excess of threshold quantities but all employers have a statutory duty under sections 2 and 3 of the Health and Safety at Work etc Act 1974 (the Act) to ensure, so far as is reasonably practicable, the health, safety of all of their employees, and to ensure that persons not in their employment but who may be affected by it, are not thereby exposed to risks to their health and safety.  It is a broad duty. In any prosecution for breach of that duty, the burden of proof shifts to the employer to prove that they did take the often subjectively assessed reasonably practicable steps needed. It is not for the prosecution to prove they did not.

The Act specifically confirms that the duty to take all reasonably practicable steps extends to the arrangements for ensuring safety and absence of risks to health in connection with the use, handling, storage and transport of articles and substances.

The Control of Substances Hazardous to Health Regulations 2002 (COSHH) and Management of Health and Safety at Work Regulations 1999 (MHSWR) also extend to all employers. The MHSWR requires a suitable and sufficient assessment to be made of risks to the health and safety of employees to which they are exposed while at work, and to others arising from the conduct of the business for the purpose of identifying the measures needed to comply with the employer’s statutory duties. That will include an assessment of any hazardous substances used or produced.

Where five or more people are employed, that risk assessment needs to be in writing. Employers must also give effect to appropriate arrangements for the effective planning, organisation, control, monitoring, and review of any preventative and protective measures identified.

More specifically, under COSHH every employer must assess the risks that arise from the use of hazardous substances to ensure that the exposure of their employees (or others) to substances hazardous to health is either prevented or, where prevention is not reasonably practicable, adequately controlled, and ensure that arrangements are made to deal with any accidents, incidents or emergencies, such as those resulting from serious spillages.

Where preventative and protective measures are identified as required, they need to follow the principles set out in Regulation 7 of COSHH and Schedule 1 to the MHSW. Those principles prioritise:

  • elimination of risk where possible (in this context for example switching to use non-harmful substances, or enclosing process and handling systems)
  • engineering plant to minimise risks (in context this may involve ventilation or overflow valves to prevent catastrophic releases of harmful substances and to vent them away from where anyone may be adversely affected, and then
  • measures such as the introduction of procedures which protect from contamination, training, signage, and PPE (such as protective clothing and respirators)

Additionally, under COSSH, where the risk assessment indicates that ensuring control of exposure is necessary for employee health, then health monitoring is also required and records of this are maintained.

Breach of the duties set out in the Act, COSHH, and in MHSW is a criminal offence and the penalty imposed for breach on conviction will depend primarily on how far short of expected standards an employer fell, and consequently who was put at risk and how serious that risk was. The higher the risk and harm potential, the higher the penalty. It is important to understand that it is the failure to appropriately manage the risk which is punished – actual harm is an aggravating feature, but no one needs to be injured for an employer to be guilty and receive a substantial financial penalty.

Continued in part 2.

Tristan Pulford | Sohail Khan | Sue Dearden

If you need further information or advice on the effectiveness of your engineered harmful substance controls please contact Tristan Pulford: [email protected] : 01530412777 

We can audit the controls in place in your workplace and assist in identifying gaps in measures in place (as well as solutions).

Tristan is a chartered mechanical and process safety engineer and is Finch Consulting’s Capability Director. Sohail is a chemical engineer experienced in process safety management. Sue is a Solicitor at Finch Consulting specialising in Health and Safety.

Finch is a leading risk management consultancy, working worldwide with blue-chip clients in multiple sectors.

As a “critical partner” to our clients, we provide confidence to be a better business by helping identify, manage and mitigate risks associated with engineering, health and safety, and regulatory compliance. This is delivered through three core areas: Asset Management, Health & Safety Management and Process Safety Management.

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