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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.
Supplement to Guideline – ‘Environmental Risk Tolerability for COMAH Establishments’
Complex Site Example v0.0
Page 12 of 35
release to the atmosphere was still required to justify its omission. For those scenarios where a gas itself may be released,
rather than the combustion products, the toxicity of the gas was reviewed. For natural gas, butane, propane, etc, the gas itself
was not considered toxic and unignited releases are ultimately unlikely therefore to present a significant environmental risk.
Given the location of the storage vessels for these gases, a release of sufficient magnitude to cause an asphyxiation risk to
environmental receptors was also deemed highly unlikely and that dispersion of the gas in the atmosphere would rapidly
reduce this risk in any case. In two cases, however, the release was considered to be potentially significant in an
environmental context for releases of hydrogen fluoride (HF) and hydrogen sulphide (H
2
S) and the release scenarios for the
process plant with the potential to generate these emissions were evaluated further.