How to Conduct an Effective Odour Impact Assessment
Understand Odour Emissions & Stay Compliant with Silsoe Odours
Operators often find the range of odour assessment services available overwhelming. But with the right approach, understanding your odour emissions can be straightforward.
"In this article, I explain the process behind our most popular service, the Odour Sampling Survey. I also provide an overview of some other types of odour impact assessment. So, continue reading to understand what to expect when working with our specialist team." James Sneath, Technical Manager, Silsoe Odours.
For related guidance on managing emissions, see our blog: How to Control Odour Emissions for Your Environmental Permit.
Why Conduct an Odour Impact Assessment?
Your environmental impact as an operator is a big deal. Odour plays a crucial role in this. People want to go about their daily lives without having to endure bad smells. You will see this reflected in odour regulatory compliance. Planning regulations and environmental permits increasingly expect operators to actively monitor and control odour emissions. How well you do this can also affect the regulator’s response to odour complaints.
Conducting an odour impact assessment provides:
- Scientific data on your odour sources and concentrations
- Guidance for mitigation or control measures
- A documented record demonstrating due diligence to regulators or in legal proceedings
How Does the Process Work?
1. Briefing – Define Your Assessment Needs
To start with, we will ask for as much information as you can provide about your odour issue. Sometimes, you will have a clear understanding of your needs and timeline. In other cases, you might be unsure. We will work with you to find the best solution for your requirements.
Key actions:
- Outline your operational processes and potential odour sources
- Indicate any timelines or permit deadlines
- Decide if an odour sampling survey, sniff survey or dispersion model is most suitable
- Agree on project scope, timelines, and budget
2. Planning – Prepare for Accurate Assessment
After you approve your survey details, we get on with planning. Good planning ensures safe and effective sampling. Our planning process includes:
Site Review
Identify access points, health & safety requirements and hazards
Odour Sources
Identify all key odour emission points
Weather & Topography
Changes in wind direction can affect sampling results
Client Approval
Confirm the methodology and survey plan before beginning
All Silsoe Odours sampling and testing is UKAS-accredited.
3. Sampling – Collect Reliable Odour Data
On the day of the survey, we:
- Arrive on-site and adapt to conditions (e.g., locked gates, weather changes)
- Collect odour samples from the sources we identified during planning
- Use specialist equipment to take all samples in triplicate, ensuring reliability and accuracy
- Record field observations and operational conditions
Silsoe Odours were recommended to me by colleagues, as they are always very good and knowledgeable. I engaged them for emissions monitoring of an oil/fuel depot and had a good experience. Their odour consultants arrived at site as arranged and completed the work efficiently and effectively.
Liam Shelmerdine, Redmore Environmental
4. Laboratory Testing – Quantify Your Odour Impact
After testing, we transport all odour samples to our UKAS-accredited laboratory. We do this within a 30-hour timeframe, in line with the requirements of BS EN 13725:2022.
Depending on your needs, we can test odour samples for:
- Odour concentration
- Odour intensity
- Odour characterisation
- Detection thresholds
- Chemical analysis
- Hedonic tone
We can also test samples collected by operators and consultants, provided the methodology complies with BS EN 13725:2022.
5. Reporting – Clear Findings & Recommendations
Finally, we put all findings and recommendations into a comprehensive report. Our reports are concise, easy to navigate and scientifically accurate. You can use them to support your efforts to control odour emissions and maintain compliance with permits.
An Odour Impact Asessment from Start to Finish
This short video shows you the steps the Silsoe Odours team takes to complete an odour sampling survey:
Additional Notes for Operators
- Conducting an odour impact assessment is a proactive approach to odour management.
- They help demonstrate compliance with odour regulations and environmental permits.
- Assessments also provide data to help you make cost-effective odour control decisions
Talk to Silsoe Odours About Assessments
I have outlined the stages for one of our odour evaluation methods. If you would like to learn more, please get in touch. For odour assessments, sampling or testing, our team of expert odour consultants can guide you.
Call: 01525 860222
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FAQs
Do I Need an Odour Impact Assessment for My Permit?
Yes. Many operators benefit from proactive assessment to demonstrate compliance and minimise complaints.
What’s the Best Method for Odour Assessment?
It depends on your site and emissions. Options include sampling surveys, sniff surveys, and dispersion models. Sometimes, you will need a combination of different assessments.
Updated 12th March 2026 (originally published 3rd March 2021)
