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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.
4.1.1
Terms used in risk assessment
Sources
The sources of pollution which could give rise to a MATTE, (for example tanks, pipework,
warehousing, process units, reactors, etc.) refer to section 4.2 ‘MATTE potential matrix’.
Note that pipelines outside of the site boundary are not covered by COMAH when
covered by the Pipeline Safety Regulations, and should therefore be excluded from this
analysis.
Credible scenarios
The scenarios under which a source could credibly pollute a receptor (for example spills,
fire, explosion), refer to section 4.2 ‘MATTE potential matrix’.
Consequence
A combination of the following:
x
the extent, severity and duration of harm to the receptor.
Refer to section 3 ‘Definition of the types of Environmental Harm’
Risk
A combination of
x
consequence and
x
frequency of occurrence (per receptor per establishment per year)
Receptor
The receptor that could be polluted by the source, refer to section 3 ‘Definition of the
types of Environmental Harm’.
Protection Layers
Risk reduction measures - either preventive layers (i.e. reduce the frequency of a
hazardous event from occurring) or mitigatory layers (i.e. reduce the consequences of a
hazardous event after it has occurred). Preventive layers typically include the primary
containment (pipes, vessels and control systems) whilst mitigatory layers include
secondary and tertiary containment or fire suppression systems.
Unmitigated consequence
The potential consequence from credible scenarios before any mitigation measures are
employed, refer to section 4.3 ‘Aggregating Risk and Risk Frequencies’. This is
essentially the worst credible consequence associated with the credible scenario, (with
no protection layers in place) and is used to establish tolerability thresholds.
Guideline – Environmental Risk Tolerability for COMAH Establishments v1.0
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