Safety: Pressure, Asphyxiation, Frostbite and Flammables
The main hazards
Refrigerant work exposes you to four recurring risks: pressure (sudden release, liquid slugging, bursting components), asphyxiation (heavier-than-air vapour displacing oxygen in pits, basements and plant rooms), cold burns (liquid refrigerant at well below −20 °C contacting skin or eyes), and toxicity or flammability depending on the fluid. A2L refrigerants are mildly flammable; A3 are highly flammable; both demand no ignition sources, appropriate ventilation and leak detection in occupied or confined spaces.
Controls candidates must know
- Personal protective equipment: gloves, goggles or face shield, protective clothing; never allow liquid refrigerant on bare skin.
- Ventilation and oxygen monitoring before entering confined plant spaces; work in pairs with a rescue plan.
- Never use a naked flame or a glowing torch to leak-test - use electronic detectors, or appropriate dyes/UV where permitted.
- Isolate and lock off electrical supplies before breaking into a circuit; capacitors and hot surfaces are secondary hazards.
- Cylinders stored upright, secured, away from heat and below their rated temperature; valves capped during transport.
Traps in questions
- "Smell it to check" - many refrigerants are odourless or only odourised, so smell is not a test.
- Assuming a leak in a low plant room will disperse upwards - many vapours pool at low level.
- Using oxygen instead of nitrogen for pressure testing or purging - oxygen plus oil is an explosion risk.
- Ignoring that a system can remain pressurised in sections after isolation.
Rule of thumb
Treat every unknown space as oxygen-deficient until measured, and treat every circuit as pressurised until proven otherwise.
Records, Leak Checking and Compliance Evidence
What must be recorded
Operators of equipment above the applicable tCO2e threshold must keep records covering: the quantity and type of refrigerant charged; any refrigerant added during service; the quantity recovered; the identity of the company or certified person who performed the work; and the dates and results of leak checks. Records must be made available to the competent authority on request and retained for the prescribed period after the last entry.
Leak-check frequency logic
The frequency follows the tCO2e band, not the mass. Higher charge bands require more frequent checks; equipment fitted with a fixed leak detection system that is itself checked at the required interval earns a longer interval. Leaks found must be repaired without undue delay, and a follow-up check must confirm the repair. Records are the evidence that all of this happened - a missing entry is treated as a failure to comply, even if the work was done.
Traps in questions
- Using the nominal charge rather than the actual charge after a top-up.
- Forgetting that leak detection system function itself must be verified and logged.
- Assuming records can be discarded at decommissioning - retention rules still apply.
- Confusing the operator's record duty with the technician's duty to hand over accurate information.
Worked example
A split system holds 8 kg of R-134a (GWP 1430). tCO2e = 8 × 1430 ÷ 1000 = 11.4 tCO2e. That falls in the band requiring periodic leak checks at the shorter interval rather than the lowest band. If a leak is found, log the date, the finding, the repair, the recharge quantity and the confirming re-check - and keep the log with the equipment history so the whole sequence is auditable.