Emergency Lighting in Critical Spaces: A Guide to High Risk Area Lighting
Introduction: why high risk emergency lighting is widely misunderstood
Emergency lighting is most often associated with escape routes and exit signage. While that focus is essential, it does not address every risk present in a building. In some spaces, a sudden loss of light creates an immediate danger rather than a simple evacuation challenge. These spaces are high risk task areas, and they require a higher standard of emergency lighting.
Emergency lighting for high risk areas is frequently misunderstood because it looks compliant at a glance. Luminaires are installed, tests are recorded, and escape routes are illuminated. What is often missing is sufficient light at the point where hazardous tasks must be made safe before evacuation can occur. Escape lighting is not designed to illuminate machinery, tools, or control interfaces to a usable level.
This misunderstanding appears across many sectors, from schools and hospitals to industrial environments. When lighting fails, the first moments matter most. Without adequate emergency illumination, operators may be unable to shut down equipment safely, increasing the risk of injury before evacuation even begins.
What this article covers and who it is for
This article explains what high risk task area lighting is and how it differs from standard emergency escape lighting. It sets out how high risk areas are identified, the core lighting requirements that apply, and why these requirements are often missed in real buildings. It also explores common applications, system design challenges, and compliance considerations.
The content is intended for building owners, responsible persons, facilities managers, consultants, and project teams involved in non-domestic buildings. It is written to support practical decision-making, particularly when reviewing emergency lighting designs, fire risk assessments, or refurbishment plans where hazardous tasks are present.
What counts as a high risk task area
A high risk task area is a location where the sudden loss of lighting could expose people to harm and where sufficient emergency illumination is required to allow a task to be made safe before evacuation. The classification is not based on room type alone, but on what activities take place and the consequences of lighting failure.
Typical risk factors include moving machinery, sharp tools, press equipment, rotating components, high temperatures, hazardous substances, or electrical testing. In these environments, operators may need to isolate power, shut down equipment, or stabilise a process before leaving the area. Visibility of emergency stop buttons and the nearest point of isolation is therefore critical.
Identification of high risk task areas relies on emergency lighting risk assessment. This assessment should consider the task being performed, proximity to hazards, the people involved, and the likelihood of confusion or error if lighting fails. It should also account for whether occupants are familiar with the space and whether stress or time pressure could increase risk.
High risk task area lighting is often discussed alongside local area lighting because the requirement is focused and task-specific rather than general. Its purpose is not to allow work to continue, but to protect people by enabling safe shutdown and controlled movement away from danger.
Where buildings commonly fall short
One of the most common shortcomings is the assumption that emergency escape lighting automatically addresses all safety risks. In many buildings, emergency luminaires are installed to meet escape route requirements, but no consideration is given to whether hazardous tasks can actually be made safe when normal lighting fails. This results in systems that appear compliant but fail in practice.
Another frequent issue is poor alignment between risk assessment and lighting design. High risk tasks may be identified in principle, but the emergency lighting layout is not adapted to reflect them. As a result, light levels may be adequate at floor level while work surfaces, machinery controls, or isolation points remain poorly illuminated.
Emergency stop button lighting is a particular weakness. Emergency stop devices are often located on machinery, walls, or control panels that fall outside standard escape lighting zones. If these points are not specifically illuminated under emergency conditions, operators may struggle to locate or operate them quickly, increasing the risk of secondary incidents.
Value engineering also plays a role. Emergency lighting is sometimes reduced late in a project to save cost, without reassessing the impact on high risk task areas. Over time, changes to layouts, equipment, or processes can further erode compliance if lighting strategies are not reviewed. These issues are rarely obvious until a power failure or inspection exposes them.
The core requirements explained with real numbers
High risk task area lighting is governed by specific quantitative requirements that go well beyond those for standard emergency escape lighting. These requirements are set out within the UK emergency lighting British standard framework, most notably BS 5266-1, and they are frequently misunderstood in practice.
The central requirement is that emergency lighting in high risk task areas must provide at least 10 percent of the normal lighting level required for the task being carried out. This is commonly referred to as the 10 percent rule. Alongside this, there is an absolute minimum requirement of 15 lux, but in most environments where hazardous tasks are performed, the percentage-based requirement is the controlling factor.
Emergency lighting lux levels must be assessed at the task plane rather than at floor level. This distinction is critical. For example, if a workspace is designed to operate at 500 lux under normal conditions, the emergency lighting must deliver a minimum of 50 lux to the relevant work surface during a power failure. That level of illumination is necessary to allow operators to see hazards clearly, locate controls accurately, and complete shutdown procedures without error.
These figures help explain why many installations that appear compliant fall short when measured. Emergency lighting layouts are often designed around escape routes, with luminaires positioned and spaced to achieve minimum floor-level illuminance. When those same fittings are expected to provide task-level lighting, performance is frequently inadequate.
The challenge is compounded by system limitations. Self contained emergency luminaires may struggle to deliver higher output levels, particularly over time as batteries age and light sources depreciate. Without careful design and verification, the assumed emergency lighting performance may bear little resemblance to actual conditions during a power failure.
The detailed definitions, illuminance requirements, and performance criteria that underpin these calculations are set out across the relevant emergency lighting British Standards, which provide the accepted benchmark for demonstrating compliance and managing risk in high risk task areas.
Why 0.5 seconds matters in high risk environments
In high risk task areas, how quickly emergency lighting activates is just as important as how bright it is. The standard requires that emergency lighting in these areas activates within 0.5 seconds of a failure of the normal supply.
This requirement recognises that danger exists immediately when lighting is lost. Operators may be using rotating machinery, handling hazardous materials, or working close to moving parts. Even a brief delay can result in loss of control, misjudgement, or physical injury before the person has time to react.
Emergency lighting 0.5 seconds is therefore not a comfort-based requirement. It is a safety-critical response time designed to prevent escalation of risk in the first moments after a power failure. This is particularly relevant where tasks require fine motor control or precise interaction with equipment.
Unlike standard escape lighting, where short delays may be acceptable, high risk task area lighting must respond almost instantaneously. This has implications for system design, control integration, and commissioning. Designers must ensure that switching arrangements, control gear, and power supplies do not introduce delays that undermine the intent of the requirement.
High risk areas by sector: where this applies in practice
High risk task area lighting is not limited to specialist industrial sites. It appears across a wide range of sectors, often in spaces that are occupied daily but rarely reviewed in detail from an emergency lighting perspective.
In schools, high risk task area lighting commonly applies in design and technology rooms, woodwork workshops, and science laboratories. These spaces often contain sharp tools, rotating equipment, heat sources, or chemicals that require controlled shutdown before evacuation. Students and staff may be working close to hazards, making immediate visibility essential if normal lighting fails.
Hospitals and healthcare environments introduce different but equally significant risks. Treatment rooms, theatres, plant areas, and clinical support spaces may contain equipment that must be stabilised or isolated before staff can safely move away. In these settings, emergency lighting must support safe decision-making under pressure, often where patients or vulnerable occupants are present.
Industrial environments provide the most obvious examples. Production lines, saw mills, tool rooms, machine presses, and processing areas frequently involve moving parts and high-energy processes. High risk task area lighting in industrial settings must allow operators to locate controls, isolate power, and avoid secondary hazards immediately following a power failure. Familiarity with the environment does not remove the risk created by sudden darkness.
System design challenges and technology choices
Meeting the requirements for high risk task area lighting presents distinct design challenges, particularly where higher illuminance levels and rapid activation times are required. Systems that perform adequately for escape lighting may struggle to meet these demands without careful planning.
Self contained emergency lighting is widely used because it is flexible and relatively simple to install. However, self contained emergency lighting often relies on individual batteries that limit output and duration. Achieving higher task-level illuminance can require additional fittings or specialist luminaires, and performance can degrade over time as batteries age and light sources depreciate.
These limitations do not make self contained systems unsuitable, but they do require realistic assessment. Designers must consider whether the required light levels can be achieved at the task plane, not just assumed based on catalogue data or spacing rules.
In larger or more complex environments, a central battery emergency lighting system may offer advantages. Central battery systems can deliver higher and more consistent output, and in some configurations can maintain full output from general luminaires during emergency conditions. This can be particularly beneficial where tasks demand higher illuminance or where uniformity and reliability are critical.
System choice should always follow risk assessment rather than cost alone. Factors such as maintenance strategy, testing regime, environmental conditions, and long-term reliability all influence whether a self contained or central battery approach is appropriate for a given high risk area.
Design, verification, and compliance in practice
High risk task area lighting must be identified early and addressed through a coordinated design process. Risk assessment should inform where enhanced emergency lighting is required, while lighting calculations should confirm that illuminance levels and response times meet the standard in practice.
Verification is essential. It is not enough to assume that emergency lighting will perform as intended. Verification should confirm that luminaires activate within the required timeframe, that task-level illuminance is achieved, and that emergency stop buttons and isolation points are clearly visible under emergency conditions. Documentation of these checks is critical for demonstrating due diligence.
Ongoing compliance depends on structured testing, clear records, and periodic review. Changes to layouts, equipment, or processes can introduce new risks if emergency lighting strategies are not revisited. A managed approach to emergency lighting compliance helps responsible persons maintain confidence that systems remain suitable over time.
Routine inspections and functional checks form part of this process, alongside longer-term verification. Understanding current emergency lighting testing requirements supports effective maintenance planning and reduces the risk of issues being identified only during an incident or enforcement action.
Why you can trust Connected Light
Connected Light is an independent lighting consultancy focused on safety-critical and compliance-led environments, with extensive experience in the design and verification of emergency lighting systems. The team works closely with building owners and responsible persons to ensure that emergency lighting strategies are based on real risk rather than assumptions.
A key part of this approach is staying aligned with evolving standards, including the changes introduced by the BS 5266-1:2025 update. These updates place greater emphasis on performance, documentation, and accountability, particularly in complex buildings where high risk task areas exist.
Connected Light holds BAFE emergency lighting certification, providing third-party audited assurance that emergency lighting services meet recognised industry benchmarks. This certification supports duty holders in demonstrating due diligence and competence. The consultancy also provides clear guidance on regulatory changes, including a detailed overview of BS 5266-1:2025 explained for building owners and estates teams.
Conclusion: Reducing risk in critical spaces
Emergency lighting for high risk areas plays a critical role in protecting people where hazardous tasks cannot simply stop when power fails. Without adequate illumination, even well-managed buildings can expose occupants to unnecessary risk in the first moments of an incident.
By identifying high risk task areas early, applying the correct standards, and verifying performance in practice, organisations can move beyond surface-level compliance. Specialist support from Connected Light helps ensure emergency lighting strategies genuinely reduce risk in critical spaces rather than merely appearing compliant.










