HSE-323 · Lesson 2 of 12 · 28 min

Codes, standards and responsibilities

Fire suppression and liquid cooling systems sit where several bodies of rules meet. Occupational health and safety law protects the workers who maintain and work near these systems. Building and fire codes require fire protection, set how it is designed and decide how it must be inspected, tested and maintained. Installation standards for sprinklers, clean agents, carbon dioxide and fire alarms fill in the detail. Environmental law governs the agents and refrigerants that can harm the ozone layer or the climate. Hazard communication law covers the chemicals in coolants and agents. Mechanical and refrigeration codes cover cooling plant. This lesson maps these rules so that you know where a given requirement comes from and who is responsible for meeting it.

HSE-320 Lesson 2 introduced the safety framework for data centres, HSE-321 Lesson 2 mapped the electrical rules and HSE-322 Lesson 2 mapped the rules for battery systems. This lesson does not repeat those maps. As in those lessons, the editions named here are those current or newly published as of 2026, and the edition that applies at a particular site is the one adopted by the authority having jurisdiction. Clause numbers are deliberately not given; read the adopted documents themselves when you need the exact wording.

Layers of rules

The rules come in layers. At the base is legislation: occupational health and safety statutes and regulations, and the fire and building legislation that adopts codes. Above that are the adopted codes, which require fire protection systems and their maintenance. The codes reference installation and maintenance standards, which become mandatory when called up. At the top are manufacturer instructions, insurer requirements and good practice guidance, which are not law in themselves but are often made binding by contracts, listings or the codes.

A layered diagram of the rules for fire suppression and liquid cooling. The bottom layer is legislation: occupational health and safety law, fire and building legislation and environmental law. The next layer is adopted codes: the building code, the fire code and the mechanical and refrigeration code. Above that are installation and maintenance standards: NFPA 13, NFPA 2001, NFPA 12, NFPA 72 or the national fire alarm standards, NFPA 25 and integrated testing standards. At the top are manufacturer instructions, listings, insurer data sheets and industry guidance for liquid cooling.
Layers of rules for fire suppression and liquid cooling systems. The Canadian and US versions name different legislation and codes but share many standards.

Occupational health and safety law

In Canada, the provincial and territorial occupational health and safety acts and regulations apply to most data centres, and the Canada Labour Code Part II with the Canada Occupational Health and Safety Regulations applies to federally regulated employers. All of them place a general duty on the employer to take every precaution reasonable in the circumstances to protect workers. Several specific requirements apply directly to the subjects of this course: rules on hazardous atmospheres and oxygen deficiency, confined spaces, emergency procedures and evacuation, training and supervision, personal protective equipment, eyewash and emergency showers where corrosive or irritant chemicals are handled, and WHMIS 2015 for hazardous products such as glycol coolants, corrosion inhibitors, biocides and some suppression agents. Workers also have the right to know about hazards, the right to participate and the right to refuse unsafe work, which HSE-101 explains.

Building and fire codes

Building codes decide which spaces need fire protection and what kind; fire codes govern how buildings are used and maintained, including how fire protection systems are inspected, tested and maintained over the life of the building. In Canada, the National Building Code and the National Fire Code are model codes adopted by the provinces and territories, sometimes with significant changes, and Ontario, Quebec, British Columbia and Alberta publish their own versions. The 2020 editions are widely in force, and the 2025 editions have been published and are being adopted province by province, so the edition at a site depends on its location. The fire code requires owners to keep fire protection systems in operating condition, to inspect, test and maintain them to referenced standards, to keep records, and to take specific measures when a system is shut down. The building code also requires integrated testing of fire protection and life safety systems to CAN/ULC-S1001 in many new buildings, which checks that systems such as fire alarms, suppression releases, door releases, fans and elevators work together as intended.

Installation and maintenance standards

Most of the technical rules for fire protection systems are in NFPA standards, which the codes in both countries reference or which authorities accept, sometimes alongside national standards. The ones most relevant to this course are shown in the table. The design detail belongs to DCE-440; what matters here is knowing which document governs which system, and that maintenance standards set duties for people on site, not only for designers.

Standards most relevant to fire suppression and cooling hazards. Editions in force depend on what each jurisdiction has adopted; 2024 and 2025 editions were current in 2026.
StandardCoversRelevance to people on site
NFPA 75 and NFPA 76 (2024)Protection of IT equipment; fire protection of telecommunications facilitiesHousekeeping, combustible materials, emergency power off and protection choices in IT and telecom spaces
NFPA 13Installation of sprinkler systems, including pre-actionClearance below heads, no hanging items from pipe, system types
NFPA 25Inspection, testing and maintenance of water-based systemsImpairment procedures, valve supervision, trip tests
NFPA 2001 (2025)Clean agent systemsSafe exposure limits, pre-discharge alarms, lockout during maintenance, enclosure integrity
NFPA 12Carbon dioxide systemsLockout valves, pneumatic time delays, warning odorants, signage
NFPA 750Water mist systemsHigh-pressure equipment, nozzle care
CAN/ULC-S524, CAN/ULC-S536 and CAN/ULC-S537Installation, inspection and testing, and verification of fire alarm systemsWho may test the alarm; impairment of detection
CAN/ULC-S1001Integrated systems testingTesting how alarm, release, fans and doors work together
CSA B52Mechanical refrigeration codeRefrigerant machinery rooms, detection, ventilation and relief

NFPA 2001 deserves particular attention because it governs the agents most often found in data centre rooms. It sets limits on the concentrations to which people may be exposed for each agent, requires alarms and time delays before discharge in normally occupied spaces where exposure limits could be exceeded, requires means to prevent discharge while people work in a protected space or on the system, and requires enclosure integrity checks so that the agent stays at its design concentration for long enough. The 2025 edition is the current edition as of 2026. Lessons 4 to 6 explain these requirements from the worker's point of view.

Environmental rules for agents and refrigerants

Many fire suppression agents and refrigerants are halocarbons, compounds containing fluorine, chlorine or bromine. Some destroy stratospheric ozone, and many are powerful greenhouse gases. Under the Montreal Protocol, production of halons, including Halon 1301 that was once the standard data centre agent, ended in developed countries in 1994, and the 2016 Kigali Amendment added a phase-down of hydrofluorocarbons (HFCs), including the agent HFC-227ea and many refrigerants. Both countries have national rules implementing these agreements.

In Canada, the federal Ozone-depleting Substances and Halocarbon Alternatives Regulations under the Canadian Environmental Protection Act control the import, manufacture and use of ozone-depleting substances and HFCs and phase down HFC consumption, and federal and provincial rules govern how halocarbon systems are serviced, how releases are recorded and reported, and who may handle them. Provinces have their own requirements for refrigerant and halocarbon handling, often including certification of technicians. The details, including any release reporting thresholds, differ by jurisdiction and are best confirmed with the site's environmental adviser.

For people on site, the environmental rules mean three practical things. First, an accidental discharge of a halocarbon agent or a refrigerant leak is an environmental event as well as a safety event, and it may have to be recorded and reported. Second, only qualified and, where required, certified technicians may service, recover or refill halocarbon systems. Third, agents and refrigerants are changing. Some existing systems use agents that are no longer made by their original manufacturer, as Lesson 4 explains, and new cooling equipment increasingly uses refrigerants with lower global warming potential that are mildly flammable, which brings new safety rules.

Liquid cooling: rules still catching up

Liquid cooling inside the data hall is newer than most of the codes. There is no single code or standard that covers all of it. The building services side, such as facility water piping, pumps, chillers and refrigeration machinery, is covered by mechanical and plumbing codes and refrigeration safety standards. The IT side is covered by product safety standards for the equipment and by manufacturer requirements. Industry guidance fills the gap: ASHRAE Technical Committee 9.9 publishes guidance on liquid cooling, including water quality and wetted materials for technology cooling systems, and the Open Compute Project publishes specifications and guidelines for cold plates, coolant distribution units and immersion. These documents are not law but are often referenced in specifications and contracts.

The occupational health and safety rules apply to liquid cooling as they do to anything else. Coolants with hazardous ingredients must have safety data sheets and labels, workers must be trained on them, and the employer must assess and control the hazards of working with pressurized liquid near energized equipment. Lessons 9 to 11 apply these general duties to specific tasks.

Who is responsible for what

Many parties share responsibility for fire protection and cooling systems in a data centre. Confusion about who does what is a common cause of incidents, especially during impairments, when one party shuts a system down and another does not know.

Typical division of responsibilities. Contracts and leases can shift some duties, but they cannot remove the legal duties of the owner and of each employer.
PartyTypical responsibilities
Building ownerKeeping fire protection systems in service and maintained to the fire code; records; notifying the fire department of shutdowns as required
Operator (if not the owner)Day-to-day operation, impairment management, emergency plan, training of site staff
Employers on site (operator, contractors, customers)OHS duties to their own workers: hazard assessment, training, supervision, PPE
Fire protection contractorQualified inspection, testing, maintenance and repair; documenting deficiencies; following impairment procedures
Mechanical and cooling contractorsSafe work on cooling systems; coordination with operations and fire protection
Customers and their techniciansFollowing site rules, reporting leaks and alarms, not interfering with protection
Authority having jurisdiction (fire chief or fire marshal)Enforcing the fire code, approving systems and changes, receiving impairment notices
InsurerSetting conditions of coverage, inspecting, receiving impairment notices

Insurers deserve a note. Many data centres are insured by companies that publish their own loss prevention standards for data centres and for fire protection systems, and those standards can be stricter than the code. They often require notice before any fire protection system is taken out of service, so impairment procedures at most sites include the insurer as well as the fire department.

Qualified people

Codes and standards require that inspection, testing and maintenance of fire protection systems be done by qualified people, and some jurisdictions require licences or certificates. In Canada, fire alarm technicians are commonly certified through the Canadian Fire Alarm Association program, and some provinces license sprinkler fitters and fire protection contractors through their trade certification systems. For a site, the practical rule is that only the designated fire protection contractor, or trained site staff acting within a written procedure, should operate valves, release controls and fire alarm functions.

The program below checks a list of planned tasks against a simple site rule: each task on a fire protection or cooling system must be done by someone with the required qualification, and tasks that impair a system must have an impairment permit. The rules and names are invented for teaching.

# Teaching check of planned tasks against invented Cedar Ridge site rules.
REQUIRED = {  # task type -> (qualification needed, impairs a system?)
    "clean agent cylinder weighing": ("fire protection technician", True),
    "pre-action trip test": ("fire protection technician", True),
    "fire alarm device test": ("fire alarm technician", True),
    "CDU filter change": ("cooling technician", False),
    "coolant top-up": ("cooling technician", False),
    "cross-connect in meet-me room": ("network technician", False),
}
planned = [
    ("Ana", "fire protection technician", "clean agent cylinder weighing", "IMP-114"),
    ("Ben", "cooling technician", "pre-action trip test", "IMP-115"),
    ("Chloe", "cooling technician", "coolant top-up", None),
    ("Dev", "fire alarm technician", "fire alarm device test", None),
    ("Eli", "network technician", "cross-connect in meet-me room", None),
]
for who, qual, task, permit in planned:
    need, impairs = REQUIRED[task]
    problems = []
    if qual != need:
        problems.append(f"needs a {need}")
    if impairs and not permit:
        problems.append("impairment permit missing")
    status = "OK" if not problems else "STOP: " + "; ".join(problems)
    print(f"{who:6} {task:31} {status}")
Output
Ana    clean agent cylinder weighing   OK
Ben    pre-action trip test            STOP: needs a fire protection technician
Chloe  coolant top-up                  OK
Dev    fire alarm device test          STOP: impairment permit missing
Eli    cross-connect in meet-me room   OK

Two tasks are stopped: a cooling technician has been assigned a sprinkler trip test, and a fire alarm test has been planned without an impairment permit. Both are real patterns. Busy sites sometimes assign work to whoever is available, and fire alarm testing is sometimes treated as harmless even though testing devices can start release sequences or send signals to the fire department if the system is not properly placed in test.

Worked problem

Tracing a requirement to its source

During a contractor briefing at Cedar Ridge, a technician asks why he must wait for the meet-me room clean agent system to be placed in manual and locked out before he can work on cable trays above the ceiling in that room. Where does the requirement come from?

Show solution
  1. The provincial occupational health and safety law requires the employer to protect workers from hazards, including accidental exposure to a suppression agent and the pressure and noise of a discharge.
  2. NFPA 2001, which the codes reference and the authority accepts for clean agent systems, requires a means to prevent discharge while people work in the protected space or on the system.
  3. The fire code requires the owner to manage the shutdown of a fire protection system, including taking alternative measures and, where required, notifying the fire department.
  4. The site's impairment procedure and permit-to-work system (HSE-221) turn these requirements into specific steps, including who may lock out the system and how it is restored.

Answer: The requirement comes from several layers at once: occupational health and safety law, the clean agent standard referenced by the codes, the fire code's rules for shutting down fire protection, and the site procedure that puts them into practice.

Common mistakes

  • MistakeAssuming the newest edition of a code or standard applies everywhere.

    InsteadCheck the edition adopted by the authority having jurisdiction for the site.

  • MistakeTreating an agent discharge or refrigerant leak only as a safety event.

    InsteadRecognize that it may also be an environmental release that must be recorded and reported.

  • MistakeLetting any available technician operate fire protection valves or release controls.

    InsteadLimit these tasks to qualified people working under written procedures and impairment permits.

  • MistakeBelieving a lease or contract moves all fire protection duties to the tenant or contractor.

    InsteadRemember that the owner and every employer keep their legal duties regardless of contracts.

  • MistakeAssuming liquid cooling is covered by a single complete code.

    InsteadCombine mechanical codes, product standards, OHS law, manufacturer requirements and industry guidance.

Summary and key terms

  • Rules come in layers: legislation, adopted codes, referenced standards, and manufacturer, insurer and industry guidance.
  • Occupational health and safety law covers workers near suppression and cooling systems, including hazardous atmospheres, chemicals and emergencies.
  • Fire codes require owners to keep fire protection in service, maintain it to referenced standards and manage shutdowns.
  • NFPA 13, 25, 2001, 12, 750 and the fire alarm standards govern the systems in this course; NFPA 2001 sets exposure limits and lockout requirements for clean agents.
  • Environmental rules control halocarbon agents and refrigerants under the Montreal Protocol and Kigali Amendment and national laws.
  • Liquid cooling is covered by a combination of mechanical codes, product standards, OHS law and industry guidance.
  • Owners, operators, employers, contractors, customers, the authority having jurisdiction and insurers share responsibilities.
Authority having jurisdiction
The organization or official responsible for enforcing a code or approving equipment and procedures.
Halocarbon
A compound containing carbon and one or more halogens such as fluorine, chlorine or bromine.
HFC
Hydrofluorocarbon, a halocarbon without chlorine or bromine; not ozone-depleting but often a strong greenhouse gas.
Impairment
A shutdown or condition of a fire protection system that prevents it from working as intended.
Integrated systems testing
Testing that confirms fire protection and life safety systems work together as designed.
Kigali Amendment
The 2016 amendment to the Montreal Protocol that phases down hydrofluorocarbons.
Montreal Protocol
The international treaty that phased out production of ozone-depleting substances such as halons.

Practice problems

Work each problem on paper first, then reveal the answer to check.

  1. Name the four layers of rules described in this lesson.

    Show answer

    Legislation; adopted codes; referenced installation and maintenance standards; manufacturer, insurer and industry guidance.

  2. Which standard governs clean agent systems?

    Show answer

    NFPA 2001, Standard on Clean Agent Fire Extinguishing Systems.

  3. Which standard covers inspection, testing and maintenance of sprinklers?

    Show answer

    NFPA 25.

  4. What does integrated systems testing check?

    Show answer

    That fire protection and life safety systems such as alarms, releases, fans, doors and elevators work together as intended.

  5. When did production of halons end in developed countries?

    Show answer

    In 1994, under the Montreal Protocol.

  6. What did the Kigali Amendment add?

    Show answer

    A phase-down of hydrofluorocarbons.

  7. Give two practical consequences of environmental rules for people on site.

    Show answer

    Discharges and leaks may need to be recorded and reported; only qualified, certified technicians may service halocarbon systems; agents and refrigerants are changing.

  8. Why are insurers often notified of impairments?

    Show answer

    Because their conditions of coverage and loss prevention standards usually require notice before fire protection is taken out of service.

  9. Who keeps the legal duty to maintain fire protection systems even if a contractor does the work?

    Show answer

    The building owner, under the fire code.

  10. Name one source of guidance for liquid cooling in data centres.

    Show answer

    ASHRAE Technical Committee 9.9 guidance or Open Compute Project specifications.

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