Checked against available publisher and regulator sources on 27 October 2026.
The UK’s main soil screening criteria have different publication dates—and different purposes. S4ULs remain based on the 2015 publication, CL’s original GAC report dates from January 2010, and the Environment Agency’s SGV series dates from 2009. C4SLs have continued to expand, with important reports published in 2024.
For environmental professionals, the priority is to select the right criterion for the contaminant, land use and exposure conditions, then check its revisions and regulatory context.
Key takeaways
- S4ULs: the core publication is from 2015. Apply its errata and the August 2015 nickel update.
- C4SLs: the programme extends beyond the original six contaminants. Later publications cover solvents, naphthalene, four PFAS and inorganic mercury.
- CL GAC: January 2010 remains the original report edition identified in this review.
- SGVs: check whether each value remains available for use. Some have been withdrawn or superseded.
- CLEA: distinguish the 2009 technical background from the software, which was updated in September 2015.
The main criteria at a glance
| Criteria | Publication or update position | What changed |
|---|---|---|
| LQM/CIEH Suitable 4 Use Levels (S4ULs) | Core publication: 2015. Errata version 1.1: 7 July 2015. Nickel update: August 2015. | Replaced the earlier LQM/CIEH GAC, expanded coverage to 89 substances and incorporated updated exposure assumptions and land uses. |
| Category 4 Screening Levels (C4SLs) | Original Defra programme: 2014. Later Phase 2 reports include 2024 publications. | Extended contaminant coverage using the C4SL framework, including interim PFAS criteria. |
| EIC/AGS/CL soil GAC | Report edition: January 2010. | Added criteria intended to complement existing SGVs and LQM/CIEH criteria. |
| Environment Agency Soil Guideline Values (SGVs) | Revised series: 2009, with subsequent withdrawals. | Updated human health screening values using the CLEA framework. The Environment Agency is no longer publishing new SGVs. |
Sources: LQM publication and updates, CL Phase 2 library, CL GAC overview, and Environment Agency LCRM guidance.
S4ULs: the 2015 publication and its corrections
LQM/CIEH S4ULs cover 89 substances across six generic land uses, with soil organic matter options for organic contaminants. They incorporate developments since 2009 while retaining a health basis of minimal or tolerable risk. The publisher continues to list the 2015 edition alongside its supporting updates. LQM: S4ULs
Two updates deserve particular attention:
- July 2015 errata: replacement phenol pages, corrections to petroleum hydrocarbon table headings, a corrected cadmium value for public parks, and a chromium III toxicological units correction. S4UL errata
- August 2015 nickel update: revised oral toxicity assumptions following an EFSA assessment. This lowered nickel S4ULs for residential land with homegrown produce, allotments and public parks. Nickel update
The published revised nickel values are:
| Land use | Nickel S4UL, mg/kg dry weight |
|---|---|
| Residential with homegrown produce | 130 |
| Residential without homegrown produce | 180 |
| Allotments | 53 |
| Commercial | 980 |
| Public open space near residential housing | 230 |
| Public parks | 800 |
These values retain the assumptions and limitations in the August 2015 update.
C4SLs: developments beyond 2014
The original six C4SL contaminants were arsenic, benzene, benzo[a]pyrene, cadmium, chromium VI and lead. Inorganic mercury and selenium were not part of that original six. C4SLs describe a low level of concern and support decisions about Category 4 under the contaminated land regime. Government screening criteria information sheet
CL’s Phase 2 publications extend coverage to:
- Vinyl chloride, trichloroethene and tetrachloroethene.
- Cis- and trans-1,2-dichloroethene, and 1,2-dichloroethane.
- Naphthalene.
- Interim criteria for PFOA, PFNA, PFHxS and PFOS.
- Inorganic mercury.
The Phase 2 library provides the individual reports.
Important 2024 additions were naphthalene in April, interim PFAS in May, and inorganic mercury in August. The PFAS criteria remain labelled interim. These dates are supported by CL’s July 2024 progress report and November 2024 progress report.
Report revisions also matter. For example, 1,2-dichloroethane version 1.1, dated January 2023, corrected a comparison with an earlier toxicological value and added a reference checklist. A revised report date does not necessarily mean its screening concentrations changed. Version control sheet
CL GAC: January 2010 remains the reference edition
The EIC/AGS/CL project reviewed data for 44 contaminants and derived GAC for 35, using CLEA version 1.06. Its purpose was to fill gaps alongside existing SGVs and LQM/CIEH criteria.
The report edition is January 2010. No later wholesale replacement of this original report was identified in this review. CL’s subsequent C4SL publications form a separate programme. CL GAC overview and downloads
SGVs and CLEA: separate the values from the software
The revised SGVs and key CLEA technical background reports date from 2009. However, it would be inaccurate to say the CLEA software was last updated then.
CLEA version 1.071 was published on 4 September 2015. It incorporated C4SL project library datasets and fixed a problem with adding new chemicals in version 1.07. Environment Agency CLEA tool
For SGVs, check the status of the individual substance. Withdrawn values can provide background information but should not be used as screening criteria. Current LCRM guidance allows published SGVs where an alternative such as a C4SL has not been developed. LCRM guidance
Applying the criteria across the UK
Current LCRM guidance says that England, Wales and Northern Ireland should use an available C4SL in preference to an SGV for human health assessment. Scotland follows the separate Scottish information note referenced in LCRM. This does not establish a universal ranking of every C4SL above every industry GAC. LCRM: selecting assessment criteria
Before selecting a value, check the contaminant’s chemical form, land use, soil properties and exposure pathways. An exceedance calls for further evaluation; it does not automatically establish that remediation is required.
These soil human health criteria also do not replace assessments of water, ecology or other receptors. Drinking water standards and environmental quality standards should be selected only where relevant to the site and assessment purpose. LCRM guidance
Bringing updated standards into ESdat
ESdat has recently compiled updated standards across North America, Europe and Australia, as announced in its July 2026 library update. These updates help users apply current guideline values, automate compliance monitoring, and incorporate standards into reporting and decision-making workflows. ESdat library update announcement
ESdat’s precompiled library supports comparisons with laboratory and field results, guideline exceedance alerts and site-specific limits. Explore the ESdat environmental standards library.
Glossary
| Term | Meaning |
|---|---|
| GAC | Generic Assessment Criteria: screening concentrations based on defined assumptions about exposure and site conditions. |
| S4UL | Suitable 4 Use Level: an LQM/CIEH soil assessment criterion for human health. |
| C4SL | Category 4 Screening Level: a soil screening concentration based on a low level of concern. |
| SGV | Soil Guideline Value: an Environment Agency human health soil screening value. |
| CLEA | Contaminated Land Exposure Assessment: the model and software used to estimate human exposure to soil contaminants. |
| SOM | Soil organic matter, which can affect contaminant behaviour and screening values. |
| PFAS | Per- and polyfluoroalkyl substances: a large group of chemicals; the interim C4SL report covers four specific substances. |
| LCRM | Land Contamination Risk Management: guidance for assessing and managing risks from land contamination. |
FAQ
Is there one latest UK GAC table?
No. Several publications coexist, and values vary by contaminant, land use and modelling assumptions. Check the relevant publisher’s report and updates.
Are S4ULs obsolete because they date from 2015?
Age alone does not determine suitability. Check the publication’s corrections, current evidence and whether its assumptions fit the site.
Does exceeding a screening value mean a site is unsafe?
An exceedance identifies a need for further evaluation. The assessment must consider how people or environmental receptors could actually be exposed.
Can the interim PFAS C4SLs screen every PFAS?
No. The report covers PFOA, PFNA, PFHxS and PFOS. It does not provide a screening value for the whole PFAS group. Interim PFAS report
What should a report record?
Record the criterion’s source, publication year, revision, land use, units and relevant soil assumptions. Explain why it is appropriate for the site.
Suggested reading on UK soil screening criteria, including GAC, S4ULs, C4SLs, and SGVs.
What are the United Kingdom’s environmental standards?
UK Waste Acceptance Criteria: current limits and what has changed
Environmental Compliance Insights: Key Statistics and Trends Across the US, Canada, UK, and Australia
What is UK Water Framework Directive: Technical report on Groundwater Hazardous Substances?
What are UK Environmental Quality Standards for Freshwaters?
Best Environmental Data Management for Compliance Reporting
What are the Standards for Drinking Water in the United Kingdom?
