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2.2.1
What the EIC/AGS/CL:AIRE GAC are
The Environment Agency of England and Wales guidance describes what SGV are and are not. These definitions
apply equally to the EIC/AGS/CL:AIRE GAC and are summarised in Box 1.
Box 1. What the EIC/AGS/CL:AIRE GAC are/are not
Definition of what EIC/AGS/CL:AIRE GAC are:
• They are scientifically based screening criteria that have been derived using the CLEA model (v1.06)
in general 2 accordance with the CLEA framework;
• They can be used as a starting point for evaluating long-term risks to human health from chemicals
in soil; and
• They provide an indication of the chemical concentration in soil below which the long-term human
health risks for site occupants (for various generic land-use scenarios) are considered to be tolerable
or minimal
• They are screening criteria to determine the need for further investigations and the need for a
DQRA.
Definition and Use
Definition of what EIC/AGS/CL:AIRE GAC are NOT:
• They do not represent the “trigger” for unacceptable intake, i.e. exceedence of the GAC does not
necessarily imply significant possibility of significant harm (SPOSH);
• They do not cover other types of risk to humans such as fire, suffocation or explosion, risks from
chemicals in groundwater or ground gas or short term and acute exposures;
• They cannot be used to evaluate risks to construction workers or non-human receptors; and
• They are not explicitly derived to define remediation standards.
2.2.2
How the EIC/AGS/CL:AIRE GAC should be used
Like the SGV, the EIC/AGS/CL:AIRE GAC have been derived based on generic conceptual site models for a number
of land-uses and making generic assumptions about receptor type and behaviour and building and soil properties.
These generic assumptions must be considered in the context of the conceptual site model to determine whether
the GAC are an appropriate tool for assessing risks at the site under consideration. The practitioner should
familiarise themselves with the suite of CLEA framework documents in order to understand these assumptions and
the methodology used for deriving GAC. In particular, the assessor should consider the following:
• Are there potential pollutant linkages present that the GAC do not consider, e.g. risk to workers
in excavations, inhalation of vapours generated from contaminants in groundwater, diffusion of
contaminants through drinking water pipes The presence of such pollutant linkages does not
preclude the use of GAC, but the assessor should recognise that the use of GAC alone will not
assess all the potential risks at the site;
2 Unlike the SGVs the EIC/AGS/CL:AIRE GAC are not in strict accordance with the CLEA framework. For example, the CLEA SR2 document
recommends the use of an expert toxicologist to review the health criteria from expert review groups and to challenge these criteria where appropriate.
Although the EIC/AGS/CL:AIRE GAC project volunteers were all experienced human health risk assessors none were qualified toxicologists and thus the
HCV have been derived on the basis of available health criteria and guidance provided in the SR2 document.
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