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Odour panellist, Sharon, has a very reliable nose!


The European Standard for olfactometry, EN13725, was published in 2003. CEN/TC264 Working Group 2 (WG2) developed the standard. WG2 consists of a team of odour specialists from across Europe. Our Director, Robert Sneath, was instrumental in the process. He has acted as the UK expert in the working group since 1996. So he now has an impressive 25 years of experience at the forefront of EN13725.

You will find the following explanation helpful in the event that you’re not familiar with EN13725:

This European Standard specifies a method for the objective determination of the odour concentration of a gaseous sample using dynamic olfactometry with human assessors and the emission rate of odours emanating from point sources, area sources with outward flow and area sources without outward flow. The primary application is to provide a common basis for evaluation of odour emissions in the member states of the European Union. BSEN13725:2003 – Air Quality. Determination of odour by dynamic olfactometry.


Together with WG2, Robert has been working towards a revision of the standard since 2012. The final version is now complete and has reached the ‘approval’ phase, ahead of expected publication in 2022.

As part of the approval phase, the revision has reached the national standards institutes for each participating country. For the UK, this is the British Standards Institute. The various institutes are currently voting to approve the revised standard, entitled BS EN13725 stationary source emissions – determination of odour concentration by dynamic olfactometry and odour emission rate. The standard reflects some improvements, particularly around odour sampling. Notably, it includes updates such as:

  • Health and safety recommendations for all staff involved with the process of dynamic olfactometry. This includes odour panellists and sampling technicians, both in the laboratory and on-site
  • More rigorous procedures for sampling and pre-dilution
  • A more thorough method to assess measurement uncertainty
  • Certain exclusions (for example, field olfactometry and measurement of exposure)
A CEN WG2 meeting about EN13725 in Delft, January 2020

A CEN/TC264 WG2 meeting about EN13725 in Delft, January 2020

WG2 met online during the pandemic

WG2 met online during the pandemic


By developing EN13725, the WG2 team had three core goals. Specifically, they wanted to create a unified standard of olfactometry which:

  • Improved consistency within each odour laboratory (repeatability)
  • Achieved comparable results amongst laboratories (reproducibility)
  • Connected the results to a traceable reference material, such as n-butanol (accuracy)

Having achieved this, EN13725 supports national bodies’ efforts in providing guidance and enforcement of environmental odour regulations. In the UK, the most notable examples are the H4 odour guidance document from the Environment Agency and the Guidance on the Assessment of Odour for Planning document from the Institute of Air Quality (IAQM). They both outline best practice criteria for effective odour management.


The Silsoe Odours laboratory is compliant with EN13725, as accredited by UKAS

The Silsoe Odours laboratory is compliant with BS EN13725

In the UK, the United Kingdom Accreditation Service (UKAS) is responsible for assessing compliance with BSEN13725. In summary, UKAS accreditation is an important measure for demonstrating quality standards and, of course, compliance with the European Standard.

We hold several accreditations at Silsoe Odours. Perhaps most importantly, we hold UKAS accreditation for both our odour laboratory and our on-site odour sampling activities.


Finally, if you would like to understand more about EN13725 and how it affects you, please get in touch. Robert now boasts 25 years experience working on the standard as its UK expert. So, he is perfectly placed to answer all your questions. Give us a call on 01525 860222, or click on the button below to reach us.

Updated 6th October 2021

One Response

  1. […] Robert is a renowned odour specialist with over 40 years’ experience at the forefront of the odour industry. Perhaps most notably, Robert acts as the UK expert for Technical Committee CEN/TC 264 “Air Quality”’. The workgroup is responsible for the ongoing development of the European Standard EN13725. […]

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