9.2 Fire Safety, Emergency Arrangements, Hot Work and Welding
Key Takeaways
CDM 2024 regulation 31 requires suitable and sufficient steps to prevent risk of injury from fire or explosion, flooding, or any substance liable to cause asphyxiation.
CDM 2024 regulation 32 requires emergency arrangements, including evacuation procedures, that everyone on site is familiar with and that are tested by being put into effect at suitable intervals.
Under CDM 2024 regulation 34, fire-fighting equipment and fire detection and alarm systems must be suitable, sited, signed, examined, tested and maintained, every worker must be instructed in their correct use, and work with a particular fire risk may be done only after suitable instruction.
A widely used hot work standard, NFPA 51B, requires combustibles within 11 metres (35 feet) of hot work to be removed or protected, and a fire watch for at least 30 minutes after the work ends.
USECHH 2000 requires a chemical health risk assessment where welding fumes or other hazardous chemicals are present, and approved respiratory protection only where other controls are impracticable or inadequate.
Fire risks on construction sites
A fire needs fuel, heat and oxygen, which is the fire triangle. Remove any one and the fire goes out. Construction sites have plenty of all three:
- Fuels: timber formwork, packaging, plastic sheeting, insulation, paints and solvents, diesel, LPG and acetylene, waste skips
- Ignition sources: welding, cutting and grinding sparks, torch-on roofing, faulty electrics, overloaded cables, smoking, generators and hot engines, arson
- Oxygen: air, plus oxygen cylinders, which make materials burn fiercely, and leaking oxygen hoses that enrich clothing
High-rise buildings under construction are especially vulnerable: fire protection systems are incomplete, escape routes change week by week, and fire services may struggle to reach upper floors.
The law: CDM 2024 regulations 31 to 34
| Reg. | Requirement (summary) |
|---|---|
| 31 | Suitable and sufficient steps to prevent, so far as practicable, risk of injury from fire or explosion, flooding, or any substance liable to cause asphyxiation |
| 32 | Where necessary, emergency arrangements, including evacuation of the site or any part of it, taking account of: the type of work; the site's size and characteristics and the number and location of workplaces; the plant used; the number of people likely to be present; and the physical and chemical properties of substances present. Everyone must be familiar with the arrangements, and they must be tested by being put into effect at suitable intervals, which means drills |
| 33 | Sufficient emergency routes and exits, leading as directly as possible to an identified safe area; signed; kept clear; emergency lighting where needed |
| 34 | Fire-fighting equipment and fire detection and alarm systems where needed: suitably sited and signed; examined, tested and maintained at suitable intervals; non-automatic equipment easily accessible; every worker instructed in the correct use of fire-fighting equipment; work with a particular fire risk may be done only after suitable instruction |
These are construction-site duties of the contractor. Most breaches carry up to RM500,000 or one year or both. The Fire and Rescue Department of Malaysia (JBPM, BOMBA) is the fire authority under the Fire Services Act 1988 (Act 341), and building fire safety for completed buildings falls under the Uniform Building By-Laws 1984. Coordinate with the local fire station on access for fire engines, hydrants and high-rise firefighting.
The site fire plan
A fire and emergency section of the construction phase plan should cover:
- Fire risk assessment by area and phase: stores, waste areas, hot work locations, basements, upper floors.
- Prevention:
- housekeeping and frequent waste removal
- storage of flammables and gas cylinders (Section 3.2)
- smoking only in designated areas
- electrical safety (Section 9.1)
- hot work control
- security against arson
- Detection and alarm: a site alarm that can be heard everywhere, for example sirens or air horns on each floor, with fire detection in cabins, stores and finished areas.
- Fire-fighting equipment: extinguishers at stores, hot work points, plant, each floor and stair; temporary dry risers or hose reels on high-rise sites as the design progresses.
- Escape: at least two escape routes where practicable, protected stairs, signed routes, emergency lighting, assembly points, and a roll-call system.
- People: fire wardens on each floor or zone, trained in extinguisher use and evacuation, and first-aiders.
- Drills: evacuation drills at suitable intervals, with lessons recorded (regulation 32(3)(b)).
Extinguishers and fire classes
Fire classes under the common international system (EN 2 and ISO 3941):
| Class | Fuel | Suitable extinguishers |
|---|---|---|
| A | Ordinary solids: timber, paper, textiles, plastics | Water, foam, multipurpose (ABC) dry powder |
| B | Flammable liquids: diesel, petrol, solvents, paint | Foam, dry powder, carbon dioxide |
| C | Flammable gases: LPG, acetylene | Isolate the gas supply first; dry powder to knock down a fire if it is safe to do so |
| D | Combustible metals | Special metal-fire powder only |
| F | Cooking oils and fats | Wet chemical; never water |
| Electrical (energised equipment) | Fires involving live equipment (not a separate EN 2 class) | Carbon dioxide or dry powder after isolating the supply where possible; never water or foam on live equipment |
Use extinguishers with the PASS method:
- Pull the pin.
- Aim at the base of the fire.
- Squeeze the handle.
- Sweep across the fire.
Always keep an escape route behind you. Tackle a fire only if it is small, you are trained, and the alarm has been raised.
Hot work control
Hot work is any work producing flames, sparks or heat that could ignite materials: welding, gas cutting, grinding, brazing, soldering and torch-on waterproofing. Regulation 34(6) of CDM 2024 means hot work may be done only by people who have been suitably instructed. Most sites use a hot work permit (Section 2.4).
Typical hot work permit conditions, based on the widely used NFPA 51B standard:
- Look for alternatives first, such as bolting instead of welding, or cold cutting.
- Remove or protect combustibles within 11 m (35 ft). Cover openings, gaps and drains so sparks cannot fall to lower floors.
- Check walls, ceilings and floors for combustibles on the other side.
- A fire extinguisher at the work, and a trained fire watch throughout and for at least 30 minutes after the work stops.
- Gas testing where flammable vapours may be present, such as tanks, drains and basements.
- Fit gas cutting sets with flashback arrestors and hose check valves. Check hoses for damage, close cylinders after use, and keep cylinders upright and secured.
- Return the permit and inspect the area before close-out.
Hot work inside a confined space needs both permits. The confined space permit is the overriding permit (ICOP 2010), and the ICOP's Appendix C gives extra recommendations for hot work in confined spaces.
Welding and cutting: health and safety hazards
| Hazard | Effect | Controls |
|---|---|---|
| Arc radiation (UV and IR) | "Arc eye" (photokeratitis), skin burns, eye damage | Welding helmet with the correct filter shade; welding screens or curtains to protect others; covered skin |
| Fumes and gases | Metal fume fever; lung irritation; long-term effects from manganese, chromium and nickel in stainless steel; ozone and nitrogen oxides | Chemical health risk assessment under USECHH; local exhaust ventilation or fume extraction; good general ventilation; approved respirators where needed; extra care in confined spaces |
| Electric shock | Shock from the welding circuit, especially in wet or confined conductive areas | Dry gloves and clothing; insulated electrode holders; correct earthing and return leads; voltage-reducing devices where available |
| Burns and fire | Spatter, hot metal, sparks | Flame-retardant clothing, gauntlets, safety boots; hot work permit controls |
| Gas cylinder hazards | Leaks, fire, explosion; oxygen enrichment | Secured upright cylinders; flashback arrestors; leak checks; never use oxygen to "sweeten" air |
| Noise | Hearing loss from air-arc gouging, grinding | Noise assessment; hearing protection zones (Noise Exposure Regulations 2019) |
| Working position | Awkward postures, working at height | Ergonomic set-up; platforms with guardrails |
USECHH regulation 15 applies the hierarchy to welding fume: for example, a process change, local exhaust ventilation and safe work practices, with approved PPE only where other controls are impracticable, as an interim measure, or as a top-up (regulation 16).
Scenario: sparks through the slab
A welder fixes steel brackets on Level 6 next to an unprotected service opening. Directly below, on Level 5, plastic-wrapped insulation is stacked against a hoarding. There is no fire watch, and the hot work permit is signed but the conditions are not met. The SSS stops the work and:
- Gets the opening covered and the insulation moved outside the 11 m zone on both levels.
- Sets up a welding screen, an extinguisher at hand and a fire watch posted on Level 5. The fire watch stays at least 30 minutes after work ends.
- Has the permit reissued after the issuer's physical check. The fire watch signs off the close-out inspection.
- Adds "openings below hot work" to the permit checklist, and briefs all welders at the next toolbox meeting.
Under CDM 2024 regulation 32, which requirement applies to a construction site's emergency arrangements?
They must be approved by the Fire and Rescue Department before each pour
They are needed only once the building is complete and occupied
They must be kept confidential from subcontractor workers
Everyone knows them, and drills test them at suitable intervals
Which extinguisher should NOT be used on a fire in an energised electrical distribution board?
A water extinguisher
A carbon dioxide extinguisher
A dry powder extinguisher
None, because all extinguishers are safe on live equipment
Following the NFPA 51B hot work standard used on many sites, what is the minimum fire watch after welding finishes?
No fire watch is needed once the welder stops
5 minutes, to see whether smoke appears
At least 30 minutes after the work stops
Only until the welder has packed the equipment away
Sections you finish are checked off in the contents.