Odour sampling methods provide practical ways to collect information from odour sources and assess them properly.

This stage involves physically capturing emissions from a process, stack, surface, or the wider site environment and turning them into measurable data.

Different odour sources behave differently. Ducts or vents release emissions in a controlled flow. Stacks often require access at height. Biofilters release odour across a surface. Because of this, a tailored sampling approach that considers the source and purpose of the assessment is most effective.

At Silsoe Odours, we carry out odour sampling in line with recognised methods and standards, including BS EN 13725:2022. We hold UKAS accreditation for odour sampling and testing, and MCERTS-accredited staff for stack sampling. This helps ensure consistent, traceable and defensible results.

The Role of Sampling in Odour Assessment

Reliable odour assessments start with reliable odour sampling.

If a sample does not accurately represent real conditions, the results can quickly become misleading. That can affect planning decisions, environmental permits, complaint investigations and odour control strategies.

In reality, the sampling stage often determines whether the rest of the assessment has value. Laboratory analysis and reporting are only worthwhile if the input information is reliable.

Choosing the Right Odour Sampling Method

It is important to select the sampling method based on the type of odour source, the purpose of the assessment and the on-site conditions.

Often, combining several methods builds a more complete picture of how odour behaves across a site.

Odour Sampling Surveys

Odour sampling surveys are the primary method for collecting representative samples from most odour sources.

This approach applies to ducts, vents and process outlets where there is access to a defined emission point. Odour consultants collect a controlled air sample directly from the source and transfer it into specialist sampling bags for laboratory analysis.

There are strict procedures to follow during UKAS-accredited odour sampling and testing. This ensures all sample results are accurate, reliable and traceable.

Stack Sampling Surveys

Stack sampling is useful when odorous emissions release from elevated stacks or flues.

This type of work involves sampling at height. As a result, it requires specialist access, equipment, safety procedures and technical knowledge. For example, sampling teams must account for flow conditions, since stack emissions behave differently from ground-level sources.

Robert Sneath, Director at Silsoe Odours, holds MCERTS accreditation for stack emissions monitoring. This supports our work in delivering high-quality stack sampling surveys that meet recognised regulatory expectations.

Stack sampling surveys often form part of compliance monitoring or planning conditions for industrial sites.

Sheet Cover Odour Sampling

Some odour sources, such as biofilters, composting areas and sludge treatment beds, do not emit from a single point. Instead, they release odour across a surface.

In these cases, placing a sealed cover over a defined section of the surface creates a controlled sampling environment. Air samples can then be collected from within this space to measure emissions from the area.

Smoke Testing

Instead of measuring odour concentration directly, smoke testing visualises airflow patterns and traces emission pathways. This makes it particularly useful for investigating fugitive emissions, locating leaks, or understanding how odour travels through a site.

Odour specialists often use smoke testing alongside other techniques, such as sniff surveys and odour sampling, to support complaint investigations and odour management planning.

Sniff Surveys

Sniff surveys focus on how people experience odour in real-world environments.

Instead of collecting a physical sample, trained assessors carry out structured observations at specific locations. This helps us understand how odour behaves once it leaves the site boundary.

During a sniff survey, assessors record the odour’s character, intensity, duration and frequency.

Sniff surveys are helpful for:

Odour Sample Collection & Handling

Odour sampling involves collecting air samples using specialist equipment, then storing and transporting them under controlled conditions to the odour laboratory for analysis.

To preserve odour sample integrity, strict handling procedures apply throughout the process, including:

Choosing the Right Odour Sampling Methods

No single odour sampling method works for every situation. The right approach depends on the type of odour source, site conditions, the purpose of the assessment and the level of detail required.

Some cases focus on precise emissions data. Others focus on real-world impact.

As a result, projects rarely rely on a single odour sampling method. Instead, they often combine different methods to understand both emissions and their wider impact.

For example:

Each method contributes a different part of the overall picture. The strongest assessments combine methods in a structured and considered way.

Reliable Odour Assessments

The correct choice of odour sampling methods forms the foundation of reliable odour assessment work. Applying the right method in the right way produces data that supports planning decisions, compliance requirements and effective odour management.

To find out more, speak to our team of odour experts.

Call: 01525 860222
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