What Is Gas Mapping?
A gas detection survey, also known as gas mapping is carried out to confirm that gas detectors are correctly positioned, that identified risks are properly managed, and that there are documentation that supports the overall safety and risk management strategy.
Gas detection systems are installed to assess the environments where flammable or toxic gases could pose a hazard. They meet legal obligations under UK health and safety legislation, such as the Health and Safety at Work Act (1974) and the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR 2002).
Why Conduct a Gas Map?
Enhance plant safety and risk awareness
Gas mapping helps increase overall plant safety by improving the probability of detecting potential flame and gas hazards. For new installations, mapping supports the design of effective fire and gas detection systems that minimise the impact of accidental gas releases. For existing systems, it provides a clear method to assess current detection performance and identify opportunities to enhance coverage and risk reduction.
Optimise resources and system design
Mapping allows engineers to determine, with accuracy, the most suitable types and quantities of flame and gas detectors needed to achieve the required detection coverage. It also enables performance measurement when incremental design changes are introduced, ensuring each adjustment leads to measurable improvement. As a result, gas mapping helps balance safety performance with cost efficiency.
Increase design precision and engineering efficiency
By taking a structured and data-driven approach, gas mapping simplifies the process of determining optimal detector layouts. It highlights areas of higher risk and provides engineers with a clear understanding of hazard likelihood and coverage needs. This systematic approach eliminates guesswork, improves design accuracy, and streamlines the overall engineering process.
The Goal of Gas Mapping
The objective of the Gas Detection Survey / Assessment is to review areas at risk, understand how those areas are occupied, identify the types of risks present (Flammable, Toxic, Oxygen Depletion, etc.), and evaluate both existing and planned mitigation measures. During the survey, an engineer will prepare a Gas Detection Risk Assessment that includes proposed Performance Targets for the Gas Detection System. Details on Performance Targets are provided below.
Each site presents unique risks; however, every Gas Detection Survey / Assessment typically includes the following elements:
Survey of the Area at Risk – The engineer will review the site to take relevant measurements, assess escape routes, emergency lighting, and overall layout. The engineer must be accompanied at all times when working in an area of risk.
Documentation Review – Ideally, documentation should be provided in advance for preliminary review. During the visit, this documentation will be used to clarify any knowledge gaps and confirm site-specific details.
Site Meeting – A meeting will be held with site representatives familiar with the risks, mitigation measures, and operational procedures. The specific risks will be agreed upon during this discussion.
Preparation of the Gas Detection Risk Assessment – The engineer will compile information gathered during the survey and propose Performance Targets for review and discussion.
Agreement of Performance Targets – Once Performance Targets are reviewed and agreed upon, the consulting engineer and the responsible engineer will jointly sign the Gas Detection Risk Assessment.
The time required to complete the Gas Detection Survey / Assessment depends on the size and complexity of the area(s) involved. Larger sites may require multiple days to complete the assessment.
Gas Mapping at Rockall Safety
Rockall Safety provides gas mapping services designed to optimise the placement and effectiveness of gas detection systems. Using advanced modelling techniques, gas mapping evaluates the behaviour and dispersion of flammable, toxic, and asphyxiant gases within specific environments. This analysis helps identify potential gas accumulation zones and ensures that detector placement offers the best possible coverage and response time. By combining site-specific data, environmental conditions, and operational factors, Rockall Safety delivers detailed reports and visualisations.
