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CDOIF
Chemical and Downstream Oil
Industries Forum
CDOIF is a collaborative venture formed to agree strategic areas for
joint industry / trade union / regulator action aimed at delivering
health, safety and environmental improvements with cross-sector
benefits.
2.3
Using this guidance
As discussed above, this guideline provides a screening methodology for carrying out a
COMAH Environmental Risk Assessment (ERA). It does not provide detailed guidance
on all aspects of ERA and for this reference should be made to Appendix 1, which
signposts other available key guidance.
The process of ERA involves:
x
Identification and evaluation of source – pathway – receptor linkages for different
credible accident scenarios. This includes demonstrating an understanding of the
hazards of the establishment, and the sensitivities of the environment.
x
Identification of tolerability criteria for relevant receptors, dependent on the
receptor type and potential level of consequence to the receptor.
x
Evaluation of risks to the receptor, through examination of accident scenarios
(their consequences and frequency) and comparing this to the tolerability criteria
derived above.
Following completion of the ERA, determine what (if any) additional measures are
required to demonstrate that the risk has been reduced to ALARP.
This guidance provides further information on specific elements of this process:
x
Section 3 – How to quantify consequence to different receptor types, in terms of
extent, severity and duration of harm. In particular to identify accident scenarios
where the level of consequence exceeds thresholds for MATTE.
x
Section 4 – Evaluating risk and making judgements against tolerability criteria.
This process includes screening out of further assessment any scenarios where it
can be demonstrated that the nature and quantity of material present do not have
MATTE potential. Sub-sections include discussion of domino sites, failure rate
data and the credit that can be claimed for mitigation.
x
Section 5 – How environmental matters can be dealt with in CBA, if this is
required
x
Section 6 – An outline of the assessment process, by reference to the concepts
introduced in previous sections, with examples.
x
The appendixes provide links to a wealth of important information, much of which
will be necessary to support an assessment of environmental risk. However,
above all, Appendix 4 is most important since it provides the agreed tolerability
thresholds for various differing consequence scales of MATTE.
Figure 1 below depicts how aspects of this approach are covered in the relevant sections
within this guidance.
Guideline – Environmental Risk Tolerability for COMAH Establishments v1.0
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