SI157001_RPT - Gasoline Overfill Protection SIS IMMEAS-SIS1 - Layers of Protection Analysis

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Simon Storage Ltd – Immingham East Terminal
Gasoline Import – Layers of Protection Analysis
P & I Design Ltd DOCUMENT NO: SI057001_RPT
2 Reed Street, Thornaby, UK, TS17 7AF ISSUE: G DATE: 29.06.12
Tel: + 44 (0)1642 617444 PAGE 11 OF 34
Fax: + 44 (0)1642 616447
For Environmental Hazards the tolerable risk levels are based on those given in Appendix 2
of the Process Safety Leadership Group (PSLG) final report into the Buncefield explosion.
These figures are based on information in document Integrated Pollution Prevention and
Control (IPPC) and Environmental Assessment and Appraisal of BAT.
Consequence Definition
Acceptable if
frequency less than
Unacceptable if
frequency more
than
Minor: Nuisance onsite only. No
off-site effects.
All shown as
acceptable
-
Noticeable Minor breach of
permitted emission limits,
but no environmental
harm
10-2 per year ~ 10 per year
Significant Major breach of
permitted emissions limits
with possibility of
prosecution
10-4 per year 10-1 per year
Severe Public warning and offsite
emergency plan invoked
Hazardous substance
releases into water course
with ½ mile effect
10-6 per year 10-2 per year
Major Serious toxic effect on
beneficial or protected
species
Widespread but not
persistent damage to land
10-6 per year 10-4 per year
Catastrophic Major airborne release
with serious off-site
effects
Site shutdown
Serious contamination of
groundwater or
watercourse with
extensive loss of aquatic
life
10-6 per year 10-4 per year
Table 4 - Environmental Tolerable Risk Frequency