HSE issues further safety alert to fuel depot operators

E071:06 4 July 2006

The Health and Safety Executive (HSE) today issued a Safety Alert to operators of COMAH fuel storage facilities and others storing hazardous substances in large tanks. Details of the Safety Alert can be found on the HSE website at: http://www.hse.gov.uk/comah/alerts/sa0106.htm

The Safety Alert comes as a result of new information received from the on-going investigation that is being overseen by the Buncefield Major Incident Investigation Board chaired by Lord Newton. Scrutiny of the workings of the high-level safety system has indicated that certain aspects of its installation and testing are critical in ensuring it operates correctly.

HSE has requested that operators of similar facilities carry out immediate checks where TAV level switches manufactured and supplied by Cynergy3 Components Limited or their predecessor companies are fitted to their storage tanks and carry out the actions detailed in the Safety Alert. HSE has also served improvement notices on the company. This requires them to alert operators using this system of the steps outlined in the Safety Alert.

Kevin Allars, head of HSE's Chemical Industries Division, said: "The Safety Alert is primarily for the attention of those companies operating oil/fuel storage facilities. However, it may also be relevant to other sites storing hazardous substances in large tanks where gauges are used.

"The relevance of the installation and performance of these switches in respect of the Buncefield incident is only one of a number of lines of enquiry. It is therefore inappropriate to comment on its relevance in the particular circumstances of Buncefield. It is also too early to say when the Buncefield investigation will conclude, or what it might say regarding these switches. However, when the fire and explosion at Buncefield first happened HSE stated that if information that affected the safe operation of similar sites came to light from the independently-led investigation it would take immediate action to draw industry's attention to it. That is being done today, and that is what HSE will continue to do as any further intelligence arises from that investigation."

Notes to editors

Safety Alert issued to all COMAH operators and industry groups:

Safety Alert to operators of "COMAH" oil/fuel storage sites & others storing hazardous substances in large tanks

The following Safety Alert is primarily for the attention of those companies operating oil/fuel storage facilities. However, it may also be relevant to other sites storing hazardous substances in large tanks where level gauges are used.

The investigation into the fire and explosion at the Buncefield oil terminal depot on 11 December 2005 is continuing. Enquiries into the workings of the high level safety system to prevent tank overfill have indicated that certain aspects of its installation and testing are critical in ensuring that it works properly. Operators of similar establishments are therefore advised to carry out immediate checks where TAV level switches manufactured by Cynergy3 Components Limited and supplied by them, their predecessor companies, or others, are fitted to their storage tanks.

Operators should check TAV level switches fitted with change over (double throw) reed switches. These switches are normally used in 'de-energise' mode to maintain alarm/trip circuits in 'normal' status.

The switches are tested by using a lever or plate fitted to the head of the switch, which can be raised to simulate a high level of liquid in the tank. If the switch is working, then alarms and trips connected to the switch should operate.

However, it is critical that after carrying out this test that the lever or plate is returned to the correct position and locked into place, using a special padlock supplied by the manufacturer, and in accordance with the manufacturer's instructions. Failure to do this can lead to the switch being inoperative in normal operating mode even though it gives the appearance of functioning normally when tested.

There are a number of this type of switch fitted at tank installations in GB and worldwide. HSE has taken urgent action to bring these details to the attention of operators of similar sites through its regulatory contacts across Europe, the USA, and Canada.

Operators should now:

• Check immediately whether they have such switches fitted, and if so:
• Ensure they have all relevant manufacturer's information concerning installation and testing and maintenance,
• Ensure they have records of correct installation, testing and maintenance,
• Ensure they are currently installed in accordance with the manufacturer's instructions, with the locking device properly fitted, and
• Complete these checks as soon as possible. [See checklist on http://www.hse.gov.uk/comah/alerts/tavcheclist.htm]

Where operators cannot confirm that the switches are working correctly then other temporary measures may be adopted, until the defects can be remedied, to ensure safe operations. For example; close supervision and dipping.

The manufacturer/supplier will be contacting known users and installers of these switches to alert them to this issue and will be providing revised instructions on the safe use, setting, cleaning and maintenance of these switches. HSE has served Improvement Notices on Cynergy3 Components Limited requiring it to carry out this work.

• HSE inspectors have a wide range of tools and techniques available to ensure that dutyholders comply with health and safety law. These tools and techniques include advice, improvement notices and prosecution. In England and Wales, inspectors' decisions on whether to prosecute for any health and safety offence also take account of the Code for Crown Prosecutors, which require that:
  • There is sufficient evidence to provide a realistic prospect of conviction; and
  • The prosecution is in the public interest.
• HSE issues safety alerts routinely to inform industry of safety risks that could be common to a number of facilities.
• The Buncefield oil depot is subject to the Control of Major Accident Hazards Regulations 1999 (COMAH). HSE and the Environment Agency are the joint Competent Authority for these regulations.
• TAV level switches, which is a brand name, are a type of high-level safety system. High-level safety systems are fitted to tanks to sense when liquid reaches its maximum level, providing the operator with a visual and/or audiable alarm, should all other alarms and controls fail to prevent this.

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