Is your plant prepared for the change from CIMAH to COMAH?

On the scale of industrial disasters the 1976 accident at a chemical plant in Seveso, northern Italy, might not have had the immediate human consequences of, say, Flixborough or Bhopal. No one was killed in the wake of Seveso's runaway reaction, but the widespread dispersion of a dioxin formed in the reaction made much of the surrounding countryside uninhabitable. And it led directly to the first `Seveso Directive', later amended to take in the lessons learnt from Bhopal and the Sandoz fire in Switzerland.

Indirectly, it was these amendments that have now resulted in the proposed Seveso II Directive. The original directive was, according to the HSE's Peter Sargent, speaking at last month's one-day seminar in London, `complex and difficult to implement... with over 170 named substances.'

Nevertheless the UK implemented the directive through the CIMAH (control of industrial major accident hazards) Regulations 1984 and later amendments.

CIMAH imposes a duty on all sites within its scope to identify major accident hazards and take steps to prevent them. Depending on the substances involved, and their amounts, sites are categorised into two tiers, with the top-tier sites required to produce safety reports and emergency plans and to inform the public who may be affected by a major accident.

However, a continuing criticism of the original Seveso directive has been that it lacks any reference to land use planning, seen by many - including the HSE - as a major element in mitigating the effects of potential accident hazards (the large death tolls at Bhopal and Mexico City were exacerbated by the uncontrolled development of shanty towns alongside the plants). This point was picked up by the Council of Ministers in 1989 who recommended its inclusion in the directive. Along with other changes, this led to proposals for a Directive on the `Control of Major Accident Hazards involving Dangerous Substances', COMAH or Seveso II. This was finally adopted in December 1996 and becomes mandatory throughout the EU on 3 February 1999.

The HSE has been consulting with industry, local authorities and emergency services, among others, and has, along with the Department for the Environment, Transport and Regions (DETR) and the Scottish Office, published a consultative document*. So, what are the main differences between CIMAH and COMAH?

If one word could be used to sum up the difference, it would be `environment'. While CIMAH concentrated on the safety aspects of plant operation, COMAH places equal emphasis on environmental protection. This is reflected in a change of `competent authority' to whom the required documentation should be submitted showing conformity with the regulations. Under CIMAH this was the HSE alone, but COMAH brings in the Environment Agency (and the Scottish Environment Protection Agency) as well.

Some delegates at the conference were naturally concerned about having to deal with an extra set of inspectors. But the HSE's Gordon MacDonald, in charge of COMAH implementation, said the executive and the agencies were currently developing detailed working arrangements to avoid duplication of effort.

In practice this should mean that documents will still only have to be submitted to a single office; the HSE and agencies will work as a team to provide operators with a single set of conclusions; and they will share inspection programmes to identify the need for joint or co-ordinated inspections.

One of the key COMAH documents is the Major Accident Prevention Policy (MAPP). Operators of top-tier sites have to include the MAPP in their submitted safety reports, while lower-tier sites require a standalone document available on request to the competent authority.

The HSE expects the MAPP to be `a short and simple document'; setting down what is to be achieved, and how it is to be done, though not in any great detail. The detail will be in other on-site documentation such as plant operating procedures, training records, audit reports and so on, to which the MAPP can refer.

This was echoed by Dr Roger Pullen, site safety adviser at Esso's Fawley refinery. As part of his theme of `keeping changes [from CIMAH to COMAH] to a minimum', he suggested that the MAPP can be covered by existing SHE policies and standards, amended if necessary, and can be `largely organisational rather than establishment specific'.

Similarly, he does not anticipate COMAH safety reports being greatly different from those currently required under CIMAH. However, they will have to reflect some detailed changes. For example, in COMAH there is a greater use of generic categories - for example, `highly flammable' or `toxic' - rather than a detailed list of notifiable materials.

While operators may be apprehensive about the proposals, the HSE and the EA say they appreciate industry's concerns and aim to make the change to COMAH as painless as possible.