Case Study - BOC Group plc

[ Chapter 7: Example 1 ]

Case Study - BOC Group plc

The Company

BOC is a global company with operations in 60 countries. The company has a portfolio of four businesses - industrial and special gases, health care, vacuum technology and distribution services. The industrial and special gases business is the most established and important activity of the company (70 per cent products). BOC produces over 20,000 gas mixtures of anything up to 99.99999 per cent purity. These gases are used in a wide variety of applications, such as the production of microchips, freezing food and water treatment.

Risk Assessment of Non-routine Releases

The BOC Group initiated the Major Hazards Review Programme (MHRP) with the objective of ensuring that large-scale hazards from their operations are properly understood and controlled. The programme focuses on recognising, managing and controlling risks to the public. The main drivers for the implementation of this programme were the catastrophic industrial accidents in Bhopal and Mexico City in 1984. The MHRP is a corporate policy implemented and put into practice by a network of co-ordinators. It is essentially about recognising, acting upon and controlling high consequence risks. The MHRP is a four-step process:

Step 1 Completion of a site activity and materials inventory.

Step 2 If quantities of these materials exceed a specified threshold level, a quantitative hazard assessment is performed which includes public exposure modelling and the generation of hazard ranges. Databases such as RTECS, TOXLINE and HSDB are used for toxicity information and models such as the Gaussian Dispersion Model and BLEVE for exposure assessment.

Step 3 If the consequences of a release extend off-site and a significant off-site population is affected, a detailed quantitative risk assessment is carried out. The objective of the QRA is to satisfy the Loss Prevention Council of BOC that the risks presented at a site are within the BOC Group guidelines and meet the company criteria (risk levels that are based on the most recent criteria used by industry and the public sector).

Step 4 If the level of risk is considered unacceptable, risk reduction measures are taken to eliminate, reduce or mitigate the risk such as making engineering changes or changes in plant design or reducing or removing inventories of materials.

Each step involves the issuing of a license. A license can be issued for a site at each of the steps in the programme ranging from Licence A at the first step for a site with no reportable quantities of hazardous materials to Licence D for a site with reportable quantities of hazardous materials, where consequences extend off-site, significant off-site population may be affected and adequate plant controls and acceptable risk is demonstrated through QRA. The steps and licensing procedure for the programme are illustrated in Figure 7.5.

Major benefits of the implementation of the MHRP are the introduction of tools such as Hazop, which identifies potential hazards at the plant design stage, better response to new regulatory initiatives to control hazards and a general reduction in inventory. The MHRP allows the BOC Group to set consistent hazard standards in all the countries in which they operate.