LQM is a specialist environmental consultancy based in Nottingham (UK) with an international reputation for assessing and managing the risks posed to human health and the environment by contaminants in soil. Increasingly this is being done within a context of sustainable development and specifically sustainable brownfield regeneration.

We provide consultancy, peer review and expert witness services, contract research and training courses on all aspects of the management of land contamination to problem holders, developers and local government.

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Webinar Recording: Correct application of BS 8485

Only £30 (excl VAT) with online card payment discount.

Toxic, asphyxiating or explosive gases can leak from the ground and accumulate in buildings, posing health risks.  BS 8485:2015+A1:2019 is the Code of practice for the design of protective measures for methane and carbon dioxide ground gases for new buildings. It describes how to characterize sites and prevent the entry of carbon dioxide and methane into new buildings.  The 2019 amended edition of clarifies the gas protection scoring methods and the criteria for gas resistant membranes.

This ~90min recording is of a Technical Briefing Webinar originally delivered on the 3rd May 2019 and includes the Q&A session at the end of the webinar (Note: only access to the recording will be provided. The original handouts are not included).  The webinar was delivered by Steve Wilson who is Technical Director of the Environmental Protection Group (EPG) Limited. Steve has authored numerous technical papers and publications and provided training relating to gassing issues over many years. Steve will provide insight into the correct application of this important, but often poorly applied, British Standard.

Prices and discounts: Prices exclude VAT.  Please note purchase is via online card payment only - a 20% discount will automatically be applied.  Any purchases make via invoice payment will be declined.  Terms and Conditions apply  A link to the webinar recording will be provided by email once payment has been received.


  • Content
  • Citation

The webinar covered:

  • The foundation of any use of BS8485 – a pictorial gCSM
  • The next important step – data quality assessment
  • Difference between hazardous gas flow rate and GSV
  • The 1% and 5% consideration for moving from CS1 to CS2 – when is it appropriate to increase the classification (differentiating between high risk and low risk sites)
  • How you should correctly apply BS8485 to your sites to arrive at a Characteristic Situation

At the end of the webinar, you will:

  • Understand better how to apply BS8485 correctly
  • Provide clients with a better service by avoiding over specification of gas protection measures where they are not required
  • Make sure developments that need it are provided with adequate gas protection

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