HVAC · Canada

FLHA for central air installation

By Safety PaperworkBuilt from provincial OHS law and CCOHS guidance · How we write and check theseUpdated November 9, 2026

Provincial OHS law requires hazards to be assessed and controlled before work starts. A field level hazard assessment (FLHA) for central air installation is done on site at the start of the shift and again whenever conditions change.

It lists the tasks, hazards and controls, and every worker signs on before starting and signs off at the end of the shift. The main hazards are disturbing asbestos, electric shock from live wiring, falling through a floor opening or void and heat stress.

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FLHA example: central air installation

This is a complete FLHA for central air installation, with 6 job steps. Open it in the builder to add your site, crew and signatures, change anything, and download a PDF. Or download the free Word template below and fill it in by hand.

Field Level Hazard Assessment (FLHA)

Ducted AC unit installation · HVAC · Example

Document FLHA-001 · Rev 1

Job steps, hazards and controls

#	Job step	Hazards	Risk before	Controls	Risk after
1	Check the roof space for asbestos, cables and access	Disturbing asbestos Electric shock from live wiring Tight spaces: attics and crawl spaces	Critical	Get an asbestos survey before work on buildings built before 1990. Elimination Seal off the work area and keep everyone else out. Engineering (guarding) If asbestos must be disturbed, keep it wet, use hand tools not power tools, and clean up with a HEPA vacuum. Engineering Follow your province's asbestos rules, including notification and trained or certified workers where required. Administrative In BC, a qualified person must inspect and write a hazardous materials report before demolition or renovation, and asbestos abatement must be done by a WorkSafeBC licensed contractor (since 1 January 2024). Administrative Stop work straight away if you find suspect asbestos. Do not touch it and tell your supervisor. Administrative Wear a fit-tested respirator suited to the work, and disposable coveralls. PPE Isolate the power before any work. Do not work live. Elimination Lock out and tag the isolation point with your own personal lock and danger tag. Engineering (guarding) Electric shock from live wiring: see step 6 for the full controls Administrative Do as much of the work as you can from outside the tight space. Elimination Turn the power off at the panel before entering where you can, as damaged wiring may be live. Engineering (guarding) Lay crawl boards across the joists so you cannot step through the ceiling. Engineering Set up ventilation and lighting in the space. Engineering Limit time in hot attics and take breaks somewhere cool. Administrative	Medium
2	Work in the roof space early in the day, with breaks and water	Heat stress Confined space entry	High	Schedule heavy work for the cooler part of the day. Elimination Provide shade over work and rest areas, and fans or cooling in attics. Engineering Supply cool drinking water close by and drink a cup every 15 to 20 minutes. Administrative Take regular rest breaks in the shade, more often as it gets hotter. Administrative Let new and returning workers build up to full work in the heat over about a week. Administrative Watch each other for dizziness, headache, confusion or stopping sweating. Stop work, cool down and get help. Administrative Have a hot weather plan, including when work stops. Administrative Wear light, loose, long-sleeved clothing, a hat or brim, and sunscreen. PPE Do the work from outside the space where you can, using cameras or long-reach tools. Elimination Isolate and lock out all pipes, power and moving parts going into the space. Engineering (guarding) Test the air for oxygen, flammable and toxic gases before entry, and keep testing during the work. Engineering Use forced ventilation to keep the air clean. Engineering Follow your province's confined space program with a written entry permit. Only trained workers enter. Administrative Keep a trained standby person outside at all times, in contact with those inside. Administrative Set up a rescue plan and rescue gear before entry. Never go in to rescue without the right gear. Administrative Wear a harness for retrieval and the respirator the air test calls for. PPE	Medium
3	Lift the indoor unit into the roof with a hoist or team	Lifting and carrying heavy loads Falling tools and materials	High	Plan to avoid carrying: have materials delivered, and old items picked up, as close as possible to where they are used. Elimination Use lighter or smaller loads: order smaller bags and shorter lengths, and drain or break down old items before moving them. Substitution Use trolleys, pallet jacks, hoists, vacuum lifters or equipment instead of carrying by hand. Engineering Use a two-person lift for anything heavy, long or awkward. Plan the route first and clear it. Administrative Keep the load close, back straight and no twisting. Turn with your feet. Administrative Rotate tasks and take breaks on long lifting jobs. Administrative Wear gloves for grip and safety boots to protect your feet. PPE Barricade and sign the drop zone under overhead work so nobody walks beneath. Engineering (guarding) Fit toe boards, kick plates and mesh screens on scaffolds and edges. Engineering Use catch fans, debris netting or covered walkways where people pass below. Engineering Tether hand tools when working at height. Engineering Keep platforms tidy. Do not stack materials near edges or above toe board height. Administrative Lower materials with a hoist, chute or rope. Never throw or drop anything down. Administrative Wear a hard hat anywhere objects could fall. PPE	Medium
4	Walk on joists or crawl boards only	Falling through a floor opening or void	Critical	Cover every hole and penetration with a fixed, secured cover marked "HOLE" or "DANGER". Engineering (guarding) Put guardrails with toe boards around stairwells, lift shafts, voids and open edges. Engineering (guarding) Install stairs early and fit temporary handrails as soon as they go in. Engineering Never remove a cover or guardrail without approval. Put it back straight away. Administrative Inspect covers and barriers daily and after other trades have been through. Administrative Keep lighting good enough to see openings, especially on lower floors and in the evening. Administrative Use a harness clipped to a rated anchor when working right next to an open void. PPE	Medium
5	Install ducts, cutting with care and wearing gloves and a mask for insulation	Cuts from sharp edges General dust	Medium	Deburr or cover sharp edges, and fit edge protectors on exposed sheet metal. Engineering Use knives with retractable or self-retracting blades. Engineering Cut away from your body and keep your other hand clear. Administrative Put used blades in a blade bin or sharps container. Administrative Use two people to handle large sheets of metal or glass. Administrative Wear cut-resistant gloves and long sleeves. PPE Use low-dust products, such as dust-reduced or pre-mixed compounds. Substitution Seal off the work area with plastic sheeting in occupied buildings. Engineering (guarding) Use tools with dust extraction and a vacuum for clean up. Engineering Lightly mist the area with water to keep dust down, away from anything electrical. Engineering Never dry sweep or blow dust off with compressed air. Administrative Wear a dust mask and safety glasses. PPE	Low
6	Connect refrigerant and power, test and commission	Refrigerant leaks Electric shock from live wiring Pressure testing	Critical	Recover refrigerant into an approved cylinder before opening the system. Never vent it. Engineering (guarding) Ventilate closed spaces and use a leak detector during the work. Engineering Only certified refrigeration technicians handle refrigerants, as your province requires. Administrative With flammable refrigerants (such as R32 or R290), remove ignition sources and use spark-free tools. Administrative Wear cold-rated gloves and safety glasses or a face shield. PPE Isolate the power before any work. Do not work live. Elimination Lock out and tag the isolation point with your own personal lock and danger tag. Engineering (guarding) Test before you touch: prove dead at the point of work with a tested voltage tester. Engineering Only licensed electricians do electrical work, to the Canadian Electrical Code and provincial rules. Administrative Check for back feeds from solar, batteries and generators that can keep a circuit live after the main switch is off. Administrative Test with water instead of air or gas where the system allows it. Never put water in refrigerant pipework, which is tested with dry nitrogen. Substitution Keep people out of the test area with signs and barriers. Engineering (guarding) Use a calibrated gauge and a relief valve set to protect the system. Engineering Test to the pressure the system calls for and hold it for the set time. Never go over. Administrative Release the pressure fully before tightening anything or fixing leaks. Administrative	Medium

PPE

CSA green triangle safety boots (CSA Z195)Safety glasses (CSA Z94.3)Cut-resistant glovesN95 respiratorFull body harness (fall arrest)Respirator fit tested to CSA Z94.4 (P100 for dust, or the type the air test calls for)CoverallsWork glovesRubber insulating glovesArc flash PPE (CSA Z462)Knee padsHard hat (CSA Z94.1)Sun protection (sunscreen, hat, long sleeves)Face shield

Plant and equipment

Power drillHand toolsPlatform ladderMobile crane: Provincial crane operator certification, qualified riggerElectrical test meter

Permits and plans

Lockout permit

Emergency

Call 911. Add the nearest hospital, the muster point and the first aid attendant for your site.

Sign-off

Supervisor and every worker sign to confirm they have read and understood this FLHA, then sign off at the end of the shift.

Free FLHA template for central air installation

Word (.docx) and PDF, Letter landscape, no email needed. Fill in your site details, then print or send it.

Word template (.docx)PDF template

Make yours in 2 minutes

Same document, filled in for your job. Answer a few yes or no questions, the crew signs on the phone, and you send the PDF.

Start this FLHA

Pre-start checklist for central air installation

Tick these off before work starts. They come from the hazards, permits and equipment in this job.

FLHA read, explained and signed by everyone on the job
Openings, voids and penetrations covered and marked
Lockout, tagout and test before touch done before work starts
Asbestos register or survey checked for the work area
Confined space permit, atmosphere test and standby person in place
Exclusion zone below the work and public kept out
Weather checked: water, shade and rest breaks planned
First aid attendant, first aid kit and emergency number (911) confirmed
PPE checked and worn: CSA green triangle safety boots (CSA Z195), safety glasses (CSA Z94.3), cut-resistant gloves, N95 respirator

The safe sequence of work

Check the roof space for asbestos, cables and access
Work in the roof space early in the day, with breaks and water
Lift the indoor unit into the roof with a hoist or team
Walk on joists or crawl boards only
Install ducts, cutting with care and wearing gloves and a mask for insulation
Connect refrigerant and power, test and commission

Hazards to watch on central air installation

The hazards most specific to this job, and the step where each one comes up.

Step 1Tight spaces: attics and crawl spacesCrawling through attics, crawl spaces or tight ceilings leads to falls through the ceiling, heat stress, shocks and cuts.

Step 2Confined space entryBad air, toxic gas or engulfment in a tank, pit, sewer or manhole overcomes workers and the people who try to rescue them.

Step 6Refrigerant leaksRefrigerant gas causes frostbite, pushes oxygen out of small rooms, and some types catch fire.

Step 6Pressure testingA pipe, fitting or cap fails under test pressure and blows apart, hitting people nearby.

Step 2Heat stressHard work in hot weather or hot attics causes heat exhaustion or heat stroke, which can kill.

Step 4Falling through a floor opening or voidA worker steps into an open hole, stairwell, lift shaft or penetration and falls to the level below.

Highest risk on central air installation: Critical before controls (B), down to Medium after controls (A), on the Canada 5 by 5 risk matrix (possible and fatality becomes unlikely and serious injury).

What changes on your site

This example covers the job itself. Your site may add more. Add controls for any of these that apply (the builder asks you these as yes or no questions):

Could anyone fall 3 metres or more, or fall any distance into machinery, water, a hazardous substance or through an opening?
Will anyone use a ladder or stepladder?
Will anyone work on a roof?
Is there a fragile roof, skylight or clear roof sheet?
Will you use a scaffold or mobile tower?

Licences and legal requirements in Canada

Equipment on this job that needs a licence, ticket or training:

Mobile crane: Provincial crane operator certification, qualified rigger

Employers must identify hazards before work starts and control them, and workers must be told about them. A field level hazard assessment is done on site, at the start of each shift or task, and reviewed again when conditions change.

Rules that apply: Provincial OHS regulation, asbestos; Provincial OHS regulation, electrical safety, and CSA Z462; Provincial OHS regulation, confined spaces; Provincial OHS regulation, fall protection.

Why FLHAs get rejected

Prime contractors and COR auditors send documents back for these reasons. This example avoids them, but check yours too.

End of shift boxes already say "None" when the form was signed at the start of the shift.
One FLHA reused for days or weeks, or a "review by" date a month away, when the work and conditions change daily.
No time of assessment and no record of any revision, which Alberta s.7(3) requires.
Workers signed that they "read" it, but nothing shows they took part, which Alberta s.8(1) requires.
Work at height with no fall protection plan where the province requires one, or no written rescue procedure for workers using fall arrest.
Permits or locates required on site but no permit or ticket numbers recorded.
No re-assessment entry after an obvious change such as weather, a new task or a new crew member.

Rules by province for central air installation

Province or territory	Key local rule	Regulator
Ontario	Fall protection (O. Reg. 213/91 s.26) applies at a fall of more than 3 m, more than 1.2 m where the work area is used as a path for a wheelbarrow or similar equipment, and at any height into operating machinery, water or other liquid, a hazardous substance, or through an opening.	Ontario Ministry of Labour, Immigration, Training and Skills Development
British Columbia	Fall protection is required where a fall of 3 m or more may occur (s.11.2). A written fall protection plan is required at 7.5 m or more where there are no permanent guardrails (s.11.3).	WorkSafeBC
Alberta	A hazard assessment must be done before work begins, and before a new work site is built (OHS Code s.7(1)). The results must be written down with the controls (s.7(2)).	Alberta Occupational Health and Safety
Quebec	Guardrails (Safety Code s.2.9.1, as amended by Decret 63-2025) are needed where a worker could fall into liquid or a hazardous substance, onto moving parts or dangerous equipment, 1.2 m or more when using a vehicle, 1.5 m or more when handling a load, and more than 3 m in all other cases.	CNESST (Commission des normes, de l'equite, de la sante et de la securite du travail)
Manitoba	A prime contractor is required whenever more than one employer or self employed person works on the site at the same time (Act s.7).	Manitoba Workplace Safety and Health Branch
Saskatchewan	An occupational health committee is required at 10 or more workers of one employer (Act s.3-22).	Saskatchewan Ministry of Labour Relations and Workplace Safety, OHS Division
Nova Scotia	Workers must be trained in fall protection before using it or working in, supervising or planning work in a fall protection area, with a refresher at least every 3 years (WHSR s.21.19).	Nova Scotia Department of Labour, Skills and Immigration, Safety Branch (OHS)
New Brunswick	Fall protection is needed from 3 m above water or the nearest permanent safe level (Reg 91-191 s.49(1)(a)(i)).	WorkSafeNB
Newfoundland and Labrador	Give written notice to the minister before starting a construction project that will last 30 days or more, with the site, location, type of work and number of workers (Regs s.8).	Government Services, Occupational Health and Safety Division
Prince Edward Island	Fall protection is needed from 3 m above the nearest safe surface or water (Fall Protection Regulations s.2(1)(a)).	Workers Compensation Board of PEI, OHS Division
Yukon	Every employer must do hazard assessments with the committee, representative or workers, and redo them after significant changes or incidents (Regs s.1.03.01).	Yukon Workers' Safety and Compensation Board
Northwest Territories	Fall protection is needed from 3 m, or lower if there is a risk of injury (s.119(1)). Guardrails are needed for falls of 1.2 m to 3 m at permanent work sites (s.119(2)).	Workers' Safety and Compensation Commission (WSCC)
Nunavut	No 911. To reach the RCMP in an emergency, dial your community's first three digits then 1111 (Iqaluit: 979-1111). Put the local fire, ambulance and RCMP numbers on every FLHA.	Workers' Safety and Compensation Commission (WSCC)

Questions

Do I need an FLHA for central air installation?

Who signs the FLHA?

The supervisor and every worker take part in the assessment and sign on before work starts, then sign off at the end of the shift. Review it and re-sign whenever the task or conditions change.

How long do I keep it?

Keep completed hazard assessments for at least 3 years (COR auditors sample the last 12 months). Review this FLHA and re-sign whenever the task, crew or conditions change.

What PPE is needed for central air installation?

Usually CSA green triangle safety boots (CSA Z195), Safety glasses (CSA Z94.3), Cut-resistant gloves, N95 respirator, Full body harness (fall arrest), Respirator fit tested to CSA Z94.4 (P100 for dust, or the type the air test calls for), Coveralls, Work gloves, Rubber insulating gloves, Arc flash PPE (CSA Z462), Knee pads, Hard hat (CSA Z94.1), Sun protection (sunscreen, hat, long sleeves), Face shield. The site rules may add more, so check with the general contractor.

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Blank FLHA template: free FLHA templates. Also for other countries: Australia (SWMS) · United Kingdom (RAMS) · United States (JHA)