Refrigerants and the Kigali Phase-Down

A clear guide to what refrigerants are, the environmental measures ODP and GWP, how the industry is moving from high-GWP HFCs to lower-GWP and natural refrigerants under the Kigali Amendment, and what it means in the UAE.

Refrigerants and the Kigali phase-downGWP decreasing →R-22 (HCFC)high GWP · ozone-depleting · phased outR-410A / R-404A (HFC)no ozone harm · still high GWPR-32 / R-1234ze (lower-GWP)lower GWP · transitionalCO₂ / NH₃ / R-1234yfvery low GWP · natural or new syntheticKigali Amendment phases down high-GWP HFCs over time — UAE is a partyGWP = warming impact relative to CO₂ over 100 years

A refrigerant is the working fluid that carries heat around the refrigeration cycle, evaporating to absorb heat indoors and condensing to release it outdoors. The choice of refrigerant affects not only how a system performs, but also its impact on the ozone layer and the climate — which is why refrigerants are now tightly regulated worldwide.

Over recent decades the industry has moved through several generations of refrigerants as environmental science advanced. The current global driver is the Kigali Amendment to the Montreal Protocol, which phases down high-global-warming refrigerants, and the UAE is a party to it.

How it works

Two environmental measures matter most. Ozone Depletion Potential (ODP) measures how much a substance harms the stratospheric ozone layer. Global Warming Potential (GWP) measures how strongly a released gas warms the climate compared with the same mass of carbon dioxide over a period, usually 100 years. A good modern refrigerant aims for zero ODP and a low GWP.

The generations tell the story. Early CFCs (such as R-12) had high ODP and were phased out under the Montreal Protocol. HCFCs (such as R-22) had lower but non-zero ODP and have been largely phased out. HFCs (such as R-410A and R-404A) solved the ozone problem with zero ODP but often have high GWP, which is the issue Kigali now addresses.

The Kigali Amendment phases down HFCs. Rather than banning them outright, it sets a schedule to progressively reduce the production and consumption of high-GWP HFCs over time. This pushes manufacturers and contractors toward lower-GWP alternatives for new equipment and encourages careful handling of existing refrigerant.

Lower-GWP and natural refrigerants are the destination. Options include lower-GWP HFCs and HFO blends (such as R-32 or R-1234ze/R-1234yf) and natural refrigerants such as carbon dioxide (R-744), ammonia (R-717) and hydrocarbons. These cut climate impact, though some bring flammability or toxicity that must be managed by design and safety class.

Safety classification guides use. Refrigerants are grouped by toxicity (A = lower, B = higher) and flammability (1 = none, 2L = mildly flammable, 2, 3 = more flammable), e.g. A1, A2L, A3. Lower-GWP options are sometimes mildly flammable (A2L), so charge limits, leak detection, ventilation and installation rules ensure they are used safely.

Main types

CFCs (e.g. R-12)First-generation; high ozone depletion; phased out under the Montreal Protocol.
HCFCs (e.g. R-22)Transitional; lower but non-zero ODP; largely phased out in new equipment.
HFCs (e.g. R-410A, R-404A)Zero ODP but often high GWP; the focus of the Kigali phase-down.
Lower-GWP HFC (e.g. R-32)Lower GWP than legacy HFCs and good efficiency; mildly flammable (A2L), so handled accordingly.
HFO / HFO blends (e.g. R-1234ze)Very low GWP synthetic refrigerants used in chillers and blends.
CO₂ (R-744)Natural, very low GWP, non-flammable; runs at high pressure, common in some refrigeration.
Ammonia (R-717)Natural, zero GWP, very efficient; toxic, so used in industrial plant with strict safety.
Hydrocarbons (e.g. R-290)Natural, low GWP; highly flammable, so used in small, sealed, charge-limited systems.

In the UAE

How GPR applies this

GPR specifies and installs air conditioning using compliant, lower-GWP refrigerants where suitable and follows good practice for leak-tight installation, refrigerant recovery and safe handling — including the charge-limit, ventilation and leak-detection measures needed for mildly flammable (A2L) refrigerants. We help Abu Dhabi clients select equipment aligned with the UAE’s Kigali phase-down and ESMA requirements, reducing both running cost and climate impact.

Frequently asked questions

What is a refrigerant?

It is the working fluid in the refrigeration cycle that absorbs heat indoors as it evaporates and releases it outdoors as it condenses, carrying heat out of the conditioned space.

What is the difference between ODP and GWP?

ODP (Ozone Depletion Potential) measures harm to the ozone layer; GWP (Global Warming Potential) measures climate warming impact relative to carbon dioxide. Modern refrigerants aim for zero ODP and low GWP.

What is the Kigali Amendment?

An amendment to the Montreal Protocol that sets a schedule to phase down high-GWP HFC refrigerants over time. The UAE is a party to it.

Why are some new refrigerants flammable?

Many low-GWP options are mildly flammable (class A2L) or more so. They are used safely through charge limits, leak detection, ventilation and installation rules matched to their safety class.

What does the refrigerant phase-down mean for building owners in the UAE?

New equipment will increasingly use lower-GWP refrigerants. Owners benefit from choosing compliant, efficient systems and ensuring leak-tight installation and proper refrigerant recovery during service.

Related lessons

Need this on your project?

GPR designs, installs and maintains MEP systems across Abu Dhabi and the UAE.