R-290
Also known as: R290, Propane, HC-290
Natural hydrocarbon refrigerant with GWP of 3. Highly efficient and low-cost. A3 flammability classification limits use to small-charge commercial applications. No phaseout risk.
R-290 (propane) is A3 classified — highly flammable. Charge limits of 150g (5.3 oz) apply in many applications per ASHRAE 15 and UL standards. Equipment must be specifically designed and certified for A3 refrigerants. Never use R-290 in equipment not certified for it.
Regulatory Timeline
Propane re-evaluated as natural refrigerant alternative following CFC phaseout pressure
EPA SNAP approval for R-290 in self-contained commercial refrigeration with charge limits
Charge limits expanded for some R-290 commercial applications; market adoption grows
What R-290 (Propane) Is
R-290 (propane) is a natural hydrocarbon refrigerant with GWP of 3 and zero ODP. As a naturally occurring substance, it is not subject to AIM Act HFC production restrictions or any foreseeable future regulation based on environmental impact. Its thermodynamic properties are excellent for refrigeration — good volumetric capacity, high efficiency, and compatibility with mineral oil lubricants.
The defining constraint on R-290 adoption is its A3 safety classification — it is highly flammable with a lower flammability limit of approximately 2.1% volume in air. This is the same flammability as domestic LPG/propane used for cooking and heating. The ignition and explosion risk requires that equipment using R-290 be specifically designed to minimize charge size (typically 150g/5.3 oz maximum per circuit in many standards), use hermetically sealed compressors, and eliminate ignition sources within the equipment.
EPA SNAP has approved R-290 for use in small commercial refrigeration equipment — reach-in coolers, vending machines, display cases — where the charge size constraints are inherent in the small equipment design. Large-system applications are not approved due to the practical difficulty of managing A3 flammability risk at higher charge volumes.
Frequently Asked Questions
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