Odour Monitoring

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Many waste and industrial facilities today have the potential to create odorous emissions from their activities. With competition for land comes the increased interaction between industry and sensitive receptors and in many cases complaints. Our expert odour monitoring service can address these and other issues before, during or after the problem.


What Is An Odour?

Odour is defined as ‘a distinctive smell, especially an unpleasant one’. For an odour to be detected, it must be:

  • Entrained in the air
  • Able to dissolve in your olfactory mucus
  • Be detectable by a receptor

An odour is a complex mix of an almost infinite number of volatile compound combinations… no too odours are the same. With that said, it is possible to both quantify the intensity and characterise the odour through monitoring.


How Is Odour Monitoring Performed?

Odour monitoring can take many forms. In its most simple guise, sniff testing allows the assessor to make a qualitative subjective assessment of the nature of the odour. Typically the assessment uses the F.I.D.O.L/R. tool:

F Frequency
I Intensity
D Duration
O Offensiveness
L Location / R Receptor

Semi-quantitative field olfactometry instruments offer a more sophisticated approach and enable the user to put some numbers against their measurements. By sniffing in-situ through an instrument with a graduated filter the user can determine an odour detection threshold.

Dynamic Dilution Olfactometry to BS EN 13725 (2003) is a fully quantitative technique that allows the tester to provide calibrated and validated measurements.

Samples of odorous air are collected in inert nalophan bags that are sealed and transported to the analysis laboratory in temperature controlled conditions for analysis within 30 hours.

Sample bags can be filled using a variety of techniques depending upon the type of source (point, diffuse, area) and the nature of the gas (temperature, humidity, expected concentration).

Analysis in the lab is undertaken by a panel of human noses who assess whether they can detect a diluted mix of the sample presented to them through one of two ports.

A second port simultaneously presents reference gas (no odour). The dilution of the sample gas is halved (odour concentration doubled) and the assessment repeated. This process happens over a range of dilutions. The odour detection threshold (expressed in ouE/m3) is defined as the point at which the odour is only just detectable to 50% of the panel.

Hedonic Tone Assessments allows for a semi-quantitative analysis of the pleasantness/unpleasantness of an odour.

Our air quality consultants will take into account the nature of the odour and work with you to advise on the most appropriate approach to testing and odour monitoring.


Why Perform Odour Monitoring?

The drivers for odour monitoring are almost as diverse as the odours themselves. Typically odour monitoring is undertaken for the following purposes:

  • Proving compliance with Emissions Limit Values contained in a PPC/EPR Permit
  • To meet the conditions of an Improvement Condition contained in a PPC/EPR Permit
  • To prove the efficiency of an abatement system
  • For subsequent modelling of emissions (for example for an Odour Impact Assessment)
  • To meet the requirements of an Odour Management Plan
  • To determine the impact of a new development
  • To address nuisance odour complaints
  • To ‘sniff-out’ fugitive emissions (e.g. leaks in plant or ductwork)
  • Due Diligence


Which Facilities Require Monitoring?

If your facility has the potential to release malodours outside of the perimeter boundary, then you may benefit from undertaking odour monitoring. If you have a regulatory requirement (as set out in a Pollution Prevention and Control Permit (PPC) / Environmental Permit Regulations (EPR)) then you have a legal obligation to comply. You may not have a regulatory requirement but nonetheless benefit from outcomes of monitoring.

We work with process operators nationwide operating in potentially odorous environments including:

  • Waste Transfer Facilities
  • Landfills
  • Anaerobic Digestion
  • Sewage Treatment Works
  • Pet Food Manufacturers
  • Paint/Ink Manufacturing


Experts In Odour Monitoring, Sampling and Analysis

Whatever your driver for testing and whatever your process, our experienced Air Quality Consultants can provide the solution to your odour monitoring requirements.

Our service doesn’t stop at monitoring. We can also offer Atmospheric Dispersion Modelling solutions using our or third party monitoring data via our Environmental Monitoring team.

Furthermore we can assist you in an Environmental Consultancy role with the development of Odour Management Plans & Odour Impact Assessments. Contact us via our Enquiry Form , info@ecl.world or call us on 01443 8401215.