EN 17628:2022 Explained: Fugitive Emissions & Optical Gas Imaging for LDAR Surveys
EN 17628:2022 & Fugitive Emissions Monitoring
BS EN 17628:2022 sets out methods for assessing emissions of volatile organic compounds (VOCs) and other gases released into the atmosphere.
Fugitive emissions are often invisible and difficult to quantify using traditional monitoring methods. As a result, specialist techniques such as Optical Gas Imaging (OGI) and Leak Detection & Repair (LDAR) surveys are becoming more prevalent. They help support both compliance and environmental performance.
Industrial operators managing gas leakage, methane emissions and environmental compliance obligations are the primary audience for the standard.
This subject sits within wider regulatory expectations for industrial odour and emissions management. For a full overview, see our guide to Odour Management in the UK: Compliance & Permitting.
What are Fugitive Emissions?
Fugitive emissions are unintended releases of gases into the atmosphere. Unlike controlled stack emissions, they escape through equipment or infrastructure.
Common release points include:
- valves and pipework
- seals and joints
- storage tanks and vents
- building fabric and containment systems
- process equipment leaks
In contrast to odour emissions, fugitive gas and VOC emissions are often invisible, odourless and difficult to locate. As a result, structured detection and monitoring are essential. Fugitive emissions are typically assessed using atmospheric monitoring techniques, such as Optical Gas Imaging and LDAR surveys.
Which Sites Does EN 17628:2022 Apply To?
BS EN 17628:2022 applies to sites where VOC or gas emissions present a leakage risk. While it is most commonly associated with biogas facilities, its scope is broader, and can include:
- anaerobic digestion (AD) and biogas facilities
- waste treatment and landfill operations
- chemical manufacturing sites
- industrial processing plants
- sites operating under environmental permits with LDAR requirements
Although not always a legal requirement, the standard is widely adopted as a framework for emissions monitoring and compliance strategies.
Leak Detection & Repair (LDAR) Surveys
Many regulated sites are required to carry out Leak Detection and Repair (LDAR) programmes.
A typical LDAR programme includes:
- scheduled inspections (twice a year to comply with EN 13725:2022)
- identifying leaks across equipment and infrastructure
- priority repairs of emissions sources
- verifying repairs
LDAR programmes are a core tool in reducing fugitive emissions over time. In particular, for methane and VOC-intensive sites.
Optimal Gas Imaging (OGI)
Optimal Gas Imaging is one of the most widely used technologies for detecting fugitive emissions.
Infrared cameras are used to visualise gas plumes that are otherwise invisible to the naked eye. As a result, operators can quickly identify active leak sources across complex or large industrial sites. The technique is particularly effective for methane detection, VOC leakage and rapid screening of process equipment.
Commonly, OGI is integrated into LDAR programmes to improve detection accuracy and survey efficiency.
Alternative Methods for Fugitive Emissions Monitoring
EN 17628:2022 outlines several approaches for assessing atmospheric emissions. Each method varies in sensitivity, cost and spatial coverage. The site’s complexity and the level of compliance evidence needed will also dictate which method is most suitable.
| Method | Description | Used For |
|---|---|---|
| Optical Gas Imaging (OGI) | Infrared imaging to visualise gas leaks | Rapid site surveys, methane/VOC detection |
| Differential Absorption Lidar (DIAL) | Laser-based atmospheric gas measurement | Large-scale emissions mapping |
| Solar Occultation Flux (SOF) | Measures gas concentrations using sunlight absorption | Regional or boundary emissions studies |
| Tracer Correlation (TC) | Uses tracer gas to estimate emissions rates | Complex source attribution |
| Reverse Dispersion Modelling (RDM) | Models emissions backwards from receptor data | Compliance verification and estimation |
Environmental Significance of Fugitive Emissions
Fugitive emissions include gases such as methane and volatile organic compounds (VOCs). These are commonly associated with industrial processes and waste-handling activities.
Methane is a particularly important greenhouse gas due to its high global warming potential. VOCs can also contribute to broader air quality impacts and regulatory concerns.
In many industrial settings, emissions are managed through monitoring programmes. For example, LDAR surveys and technologies including Optical Gas Imaging (OGI).
For a broader discussion of how emissions affect the environment, see our article on odour management and climate change.
How EN 17628:2022 Supports Compliance
When applied correctly, BS EN 17628:2022 can support:
- environmental permit compliance
- LDAR programme design
- strategies to quantify emissions
- regulatory reporting requirements
- internal environmental audits
The standard provides a structured framework for identifying and managing emissions that might otherwise go undetected.
How EN 17628:2022 Relates to Odour Management
Although EN 17628:2022 focuses on atmospheric emissions, there is often an overlap with odour management.
In some cases, fugitive gas leaks may also release odorous compounds. Containment failures can contribute to both odour and emissions issues. In addition, poor infrastructure integity can affect multiple environmental pathways.
For related guidance, see:
How Silsoe Odours Can Help
At Silsoe Odours, we support operators with practical emissions monitoring and compliance solutions. If you would like to learn more about LDAR surveys, Optimal Gas Imaging or EN 17628:2022 compliance, we can help.
Call: 01525 860222
Follow: LinkedIn | X (Twitter) | Facebook
Summary
EN 17628:2022 provides a structured approach for assessing fugitive and diffuse emissions, particularly VOCs and methane. When combined with technologies such as Optical Gas Imaging and LDAR programmes, it forms part of a modern approach to industrial emissions monitoring and environmental compliance.
Published September 2022. Last updated April 2026.
