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Safety and environmental standards for fuel storage sites
Final report
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Application to existing COMAH establishments
15 Figure 1 summarises the application of this guidance to existing COMAH establishments. It
should be noted that this figure is to aid decision making rather than to set priorities.
Existing establishments with tanks storing gasoline
16 Establishments storing gasoline in bulk tanks form the highest priority for PSLG. They represent
the activities where PSLG expects to see the highest standards of control of risks of both the
integrity of plant and equipment and in process safety management. Existing establishments with
tanks falling within the definition set out in paragraph 24 should, therefore, meet this guidance in full.
17 PSLG wishes to see a rigorous approach to primary and secondary containment and to
on-site emergency arrangements within this category of establishments. This is to ensure that the
standards will be, where necessary, significantly higher than before the Buncefield incident.
18 Particular emphasis is given to overfill prevention as this is the primary means by which
another major incident can be prevented. Accordingly, Parts 1 and 2 together with Appendix 4
set a rigorous standard with fully automatic overfill protection to safety integrity level 1 (SIL 1) as
defined in BS EN 61511 as the benchmark. To limit the environmental consequences of an overfill
incident particular attention should be given to standards of secondary and tertiary containment
as set out in this guidance. The high standards of on-site emergency arrangements needed to
limit the consequence of an incident are also set out.
Existing establishments storing products that may give rise to a large vapour cloud in
the event of an overfill
19 PSLG has undertaken work to determine whether other liquids outside the criteria set out in
paragraph 24 have the potential to give rise to a large vapour cloud in similar circumstances to
those at Buncefield. The results of this work are given in Appendix 1. This methodology can be
used to determine the potential for liquids to form a large vapour cloud in the event of an overfill.
An indicative list of such substances is also provided.
20 The CA together with industry will determine the extent to which this guidance should apply to
tanks meeting the criteria in Appendix 1. Following the publication of this guidance a programme
of work will be started to establish a strategy for compliance taking account of the nature of the
risk and severity of the consequence of a major accident. In the meantime, dutyholders should
take account of this guidance in complying with their normal legal duties under COMAH.
Existing establishments with tanks falling within scope of Part 2 of the COMAH
Competent Authority Containment Policy
21 Dutyholders should comply with the recommendations in Part 4 of this guidance (Engineering
against loss of secondary and tertiary containment) so far as is reasonably practicable.
22 Dutyholders should take account of the good practice guidance in other parts of this report
when determining control measures for the bulk storage of liquid dangerous substances.
Existing establishments with other tanks falling within scope of Part 1 of the COMAH
Competent Authority Containment Policy
23 This report contains generic guidance on the storage of bulk liquids, product transfers and
management systems, including competence and human factors. Therefore, dutyholders should
take account of the good practice guidance in this report when determining control measures for
the bulk storage of liquid dangerous substances.