Energy and Climate Change CommitteeWritten evidence submitted by the Health and Safety Executive

1. Are the costs of COMAH similar for oil refineries and storage facilities?

No, the costs for oil refineries which always include storage facilities are likely to be higher than for stand a alone storage sites. This reflects the significantly higher hazards associated with the complex processing activities taking place at refineries and the wider range of dangerous substances involved in these processes, and hence the additional regulatory activity refineries will receive.

The COMAH Competent Authority (CA) has developed methodologies to ensure its regulatory activities are proportionate to the hazards and risks posed on and off site, are targeted at critical control measures, take into account an operator’s performance, and are consistent across the CA regulatory partners.

As the CA recovers the cost of its regulatory activity directly from individual operators on an hourly basis, the regulatory costs to refineries will be higher than to simpler storage sites.

Refineries will incur higher costs for capital expenditure, maintenance of plant and equipment, and employing suitably skilled personnel. Such measures are intrinsic to running complex and high risk processes and are not necessarily a cost of COMAH in their own right.

2. Are there different risks associated with oil refineries and storage facilities?

Yes, the key difference is complexity and hazard profile. Oil refineries perform complex processing tasks using heat and pressure to break down crude oil into its constituent components such as gasoline, diesel fuel and Liquefied Petroleum Gas. Storage facilities involve much less complex plant and very little, if any, chemical processing.

Oil refineries are typically large sites with extensive piping linking separate chemical processing units. Large quantities of flammable and toxic substances are stored, transported and processed using sophisticated plant and equipment.

3. There is concern from the refining and importing industry that legislation is too prescriptive and changeable. For example, Okios said:

We had put the very latest, highest standard of safety overflow devices on the tanks, but they [HSE] insisted we put an overflow on those tanks. Less than a year later, they are now giving guidance out that you do not necessarily need to put the overflows on these tanks. Now, I suspect Greenergy and us incurred—certainly we incurred—over £250,000 just on that piece of kit that they have now identified that they do not think they need.

Is this correct and if so why did this change in policy occur?

The COMAH Regulations are goal-setting in nature and have changed little since they came into force in 1999 and the subsequent amendments in 2005.

Although there has been no change in policy, as a response to lessons learnt following the Buncefield explosion, the refining and fuel storage sector together with the CA, agreed there was a need to have clearer standards for the sector. An industry group—the Process Safety Leadership Group (PSLG)—chaired by a refinery manager and which included representatives from the CA, worked together to produce new standards that were published in 2009. Industry representatives sought clarity and certainty over control of major hazards and it was largely industry’s direction that resulted in the level of detail. The PSLG publication makes its status as guidance clear and that alternative means to comply with COMAH may be taken.

The situation that Oikos refers to was not in relation to this standard or COMAH but to a site specific set of circumstances relating to its plans for growth. The site proposed a change that significantly increased risk to the surrounding population. In order for the change to be implemented and to maintain previous levels of risk to the local population, HSE advised that this could be achieved by installing the additional overflow. In this way the twin objectives were met: of Okios’s business needs and growth; and the needs for protection of the local population. In different circumstances eg if the changes to plant did not significantly affect off site risk, HSE would not have advised on the need for overflow. This in line with HSE’s principle of enabling high hazard activities and requiring measures which are proportionate to the risk.

4. The Phillips 66 stated:

We are very supportive of the new direction and legislation that is coming out of the Buncefield incident. What we would argue is that it is being crafted in a way that is too prescriptive. Rather than setting a target for the reducing risk and allowing each business to risk-assess how best to reduce that risk, it is being rather prescriptive in saying, “You must install this type of equipment”, which is not necessarily the most cost-effective way of reducing the risk.

What are your views on this? Why does the HSE take a prescriptive approach?

The response above is also relevant to this question. The CA welcomed industry’s involvement in developing the guidance and the approach taken after Buncefield. Nevertheless, the position remains that it is for industry, as duty holders who come under the scope of COMAH, to demonstrate that they comply with the Regulations. Whilst guidance is available to advise them on reliable routes by which they can do that, the option remains for industry to show compliance with the law by other risk assessed means—which is the position set out by Phillips. This combination of goal setting law backed by more detailed guidance provides clarity for those businesses that wish to follow the guidance, and flexibility for those who wish to develop their own tailored solutions that meet the goals laid down in law.

Written by: Sandra Ashcroft, Head Chemical Industries Policy, HSE

Cleared by: Peter Brown,, HID Policy, HSE

11 July 2013

Background Notes

COMAH stems from the Seveso Directive (currently 96/82/EC) that concerns the control of major accident hazards involving dangerous substances. The Directive aims to prevent major accidents, ie low frequency but high consequence events, and limit the consequences to people and the environment of any that do happen. It applies where large volumes of dangerous substances are present, or may be produced, and has two levels—“lower tier” and “top tier” with additional obligations for the more hazardous sites. Oil refineries will nearly always be top tier sites whereas storage facilities could be top tier, lower tier or even outside the scope of COMAH, depending on inventories. At all COMAH sites there will be potential for a major accident that could affect both workers at the site as well as the surrounding population, and the environment both on and off site. Examples of major accidents in the oil refining and storage sector are explosions and fires at the Chevron Pembroke refinery in June 2011 that killed four workers and seriously injured another, Texas City, USA, in 2005 where 15 workers were killed and around 170 injured and the Buncefield oil storage depot in December 2005 where there were over 40 minor injuries and significant environmental impact, nevertheless the scale of the incident was such that if it had happened during working hours, then there would have been many fatalities.

In Great Britain, COMAH is made under the Health and Safety at Work etc Act 1974. The land use planning aspects of the Seveso Directive, addressing both the location of major hazard sites as well as the development of land around them, are made under the Town and Country Planning Act 1990. The Department for Communities and Local Government, the Scottish Government and the Welsh Government are responsible for land use planning legislation which puts into effect the Directive.

COMAH is enforced by a joint Competent Authority (CA) comprising HSE and the Environment Agency in England, the Scottish Environment Protection Agency in Scotland and Natural Resources Wales in Wales. The COMAH regulatory regime places statutory duties on COMAH sites to take all measures necessary to prevent major accidents and limit their consequences. The CA has a statutory responsibility to provide regulatory oversight of COMAH sites through, for example, conducting site inspections and investigation work, and assessing safety reports for the higher hazard “top tier” sites. The CA is required by COMAH to recover the costs of its regulatory activities from COMAH duty holders, based on the principal that the tax payer should not have to pay. The CA’s site prioritisation methodology is available at:

For making land use planning decisions, local planning authorities have to strike a balance between the needs of industry, the community and the interests of safety. HSE’s role in this process is to provide safety advice to the planning authorities to help them make informed decisions.

Following the Buncefield incident a Process Safety Leadership Group Guidance was established comprising industry, trades union and CA members that subsequently published guidance “Safety and Environmental standards for Fuel Storage Sites” available at:

July 2013

Prepared 25th July 2013