Hazards and control measures
Fire hazards and control measures
Fire hazards created by the work itself: hot works, flammable materials and waste, ignition sources, temporary electrics and blocked escape routes. Who is harmed, what CDM 2015 and the Fire Safety Order expect, and a worked example from a completed RAMS.
What are the main fire hazards at work?
A fire needs an ignition source, fuel and oxygen, and building work brings plenty of the first two: welding, grinding, heaters, electrical equipment and smoking materials on one side, and flammable liquids, LPG, timber, plastics, foam and waste on the other. HSE estimates there are hundreds of fires on construction sites each year. The controls are to remove or separate the ignition sources and the fuel, keep escape routes clear, have a way to raise the alarm and the right extinguishers at the work, and make sure everyone knows the plan.
Last updated . Facts checked by the SiteSurvey team on 24 October 2026 against HSE: General fire safety on construction sites, HSE: Construction fire FAQs, HSE: Fire safety in construction (HSG168) and The Construction (Design and Management) Regulations 2015.
Where fire hazards come from in the work
Most fires on a job start where an ignition source meets fuel that should not have been there. HSE lists the usual ignition sources as heaters, naked flames, electrical equipment, hot work such as welding, and smoking materials. The fuel is flammable liquids, wood, plastic, foam, LPG, acetylene and waste. A plumber brazing next to a stack of packaging, a welder in a plant room with rags and solvent tins on the floor, a roofer with a torch near timber, and an overloaded temporary lead under a pile of offcuts are all the same hazard in different trades.
The work also creates a second hazard: it can take away the means of escape. Materials stacked on a stair, a fire door wedged open for a cable run, or an alarm isolated for dusty work and not put back can turn a small fire into a serious one. This page is about the fire hazards the work brings with it. The premises fire risk assessment for the building itself is a separate duty on the responsible person, covered by the fire risk assessment template.
Who is harmed, and how
HSE estimates there are hundreds of fires on construction sites every year, and notes serious fires in buildings undergoing refurbishment too. The people at risk are the crew doing the work, other contractors, visitors and anyone vulnerable nearby. In an occupied building that means the staff, patients, pupils or residents who rely on escape routes, fire separation, alarms and sprinklers that the work must not interfere with.
The harm comes mostly from smoke and from being trapped. A crew working below ground or high in a structure with a single way out is exposed to smoke well before the flames reach them. Burns are the injury people picture, but a fire that starts at the end of the shift in waste left behind, and is found hours later, is the one that threatens the whole building. HSE advises keeping the site secure, especially at night and at weekends.
What the law expects
On construction work, CDM 2015 requires suitable and sufficient steps to prevent, so far as is reasonably practicable, the risk of injury from fire or explosion. Start by removing the hazard: a cold cutting or mechanical method instead of hot work, and flammables kept out of the building. Then separate and reduce: keep stored materials and waste to a minimum in designated areas, clear waste daily, and keep ignition sources away from what could burn. The Regulatory Reform (Fire Safety) Order 2005 sets the general fire precautions on site, usually through the principal contractor as the responsible person.
Around those controls sit the emergency arrangements. Escape routes stay clear and lead to a safe assembly point, with signs and lighting where needed. There is a distinctive way to raise the alarm that can be heard over site noise. Extinguishers suited to the fire risk sit at identified fire points and at any hot work, and nominated people are trained to use them. Everyone on site knows the plan. In SiteSurvey, the RAMS template records the fire point, the alarm and the assembly point for each job, has a permits page for a hot works permit, and the Suggested controls list puts removing the fuel and the ignition source ahead of extinguishers.
Suggested controls
Fire: control measures, most effective first
These are the 5 controls the SiteSurvey RAMS and risk assessment forms offer for this hazard as a tick list, grouped by their level in the hierarchy of controls. They are a starting point from HSE guidance, not an assessment of your job: tick what applies and say how it works on your site. If only personal protective equipment is ticked, the form says so. How suggested controls work and the hierarchy of controls explained.
Take the hazard away altogether, usually by doing the job a different way or from a different place.
- Flammable materials stored outside the building or in a cabinet
Keep people away from the hazard with a physical measure: a guardrail, a barrier, extraction, isolation.
- Extinguishers available at the work and the crew shown where they are
Change the way the work is done: a permit, a check, training, supervision, timing.
- Fire routes and exits kept clear throughout the work
- Waste removed from the work area every day
- Alarm, assembly point and how to raise the alarm covered in the briefing
Offered to: every type of work in the RAMS form.
Try it
Build the controls for fire
Tick the controls you would put in place, see which levels of the hierarchy they reach, and score the risk before and after. Or fill in the example from a completed RAMS to see how one crew did it.
Interactive
Try it: fire
Works the same way as the RAMS form. Nothing you tick is saved or sent anywhere.
Your controls, by level
- Eliminatenot ticked
- Substituteno control at this level for this hazard
- Engineeringnot ticked
- Adminnot ticked
- PPEno control at this level for this hazard
Nothing ticked yet.
3. Score the risk with these controls
What the law says
- Regulatory Reform (Fire Safety) Order 2005
- General fire precautions in England and Wales: the responsible person assesses the fire risk and puts measures in place for escape, warning and fighting fire. HSE enforces it on construction sites.
- Construction (Design and Management) Regulations 2015, regulations 29 to 32
- Prevent the risk of injury from fire or explosion, plan for foreseeable emergencies, keep emergency routes and exits clear and signed, and provide fire detection, alarms and fire-fighting equipment with trained people.
- Dangerous Substances and Explosive Atmospheres Regulations 2002
- Where flammable substances such as solvents, paints or LPG are used, identify the risks, eliminate or control them, limit the effects of an incident and have emergency arrangements in place.
Worked example
Fire in a completed RAMS
The hazard entry exactly as it was recorded in one of our completed example RAMS: the controls ticked from the list, how they apply on that job, and the score before and after the further action.
Electrical and M&E
Wheatstone Outpatients Building: plant room heating pipework repair
- Hazard
- Fire: Plant room B02 and the single escape route up the plant room stair to the service corridor
- What could happen, and to whom
- A fire starting in the room from the hot works or from waste, with the crew below ground and one stair out, and smoke reaching the service corridor and the clinics above. The crew, estates staff and the building occupants.
- Controls ticked
- Flammable materials stored outside the building or in a cabinet
- Fire routes and exits kept clear throughout the work
- Waste removed from the work area every day
- Extinguishers available at the work and the crew shown where they are
- Alarm, assembly point and how to raise the alarm covered in the briefing
- How they apply on this job
- No flammable liquids are kept in the room: the cutting paste and inhibitor are in the van and brought down only when used. The plant room stair and the corridor outside are kept clear of pipe, tools and leads at all times, with the fire door to the corridor closed and not wedged. Welding electrode stubs, rags and swarf go into a steel bin with a lid and are taken out to the van at lunch and at the end of each day. The fire point (two foam, one CO2, blanket) sits at the foot of the stair and the crew are shown it at the briefing. The alarm is raised at the break glass at the top of the plant room stair, the hospital emergency number is called from the plant room phone, and the assembly point is marker B in the ambulance bay car park.
- Risk with these controls (likelihood x severity)
- 2 x 5 = 10 (Medium)
- Further action
- Estates duty officer to confirm the corridor break glass and the plant room phone are working at the Saturday permit sign-off. Fire door self-closer checked at the same time. Owner: P. Marsh.
- Residual risk
- 1 x 5 = 5 (Medium)
A fictional job, filled in as a worked example. The form and the report are real.
It also appears in distribution board replacement in an occupied office and clearing and deep cleaning a void flat. All eleven completed RAMS.
Fire: common questions
Which extinguishers should be at the work?
The ones that match what could burn. HSE's guidance is water for wood, paper and cloth, dry powder or foam for flammable liquids, and carbon dioxide for electrical fires. Hot work needs its own extinguishers at the point of work, not just the nearest fire point. In the worked example, the fire point at the foot of the plant room stair has two foam, one CO2 and a fire blanket, and the crew are shown it at the briefing.
How should we raise the alarm on a building site?
With a signal everyone recognises and can hear over the site noise. On a small, low-risk site that can be a klaxon, an air horn or a whistle. Larger or higher-risk sites need an interconnected system of call points and sounders, tested regularly. In an occupied building, the briefing should say whether the crew use the building's own break glass points and where the assembly point is.
What do we have to check when working in an occupied building?
That the work does not interfere with the building's escape routes, fire separation, alarms, dry risers or sprinklers. Fire doors stay shut and are not wedged for cables or deliveries. If a detector has to be isolated for dusty or hot work, agree it with the building's duty holder and confirm it is restored at the end of each shift. Stairs and corridors you carry materials through must be left clear.
Can waste stay on site overnight?
Keep as little as possible, and only in a designated, secure area away from the building and from ignition sources. HSE advises reducing stored materials and waste and keeping the site secure out of hours, because rubbish left inside is easy fuel for a fire. Clearing the work area at the end of every day is the simplest control there is, and the RAMS tick list includes it.
Last updated . See every hazard in the library.
Write the RAMS with these controls already listed.
Pick the hazard, tick its controls, score it and brief the crew, on a phone or laptop. The report goes to the client as one PDF.