COLUMBUS, Ohio — Recent questions from the HVACR industry have focused on whether imported A2L refrigerant cylinders are safe to use with CG-1 rupture disks, or if all A2L gases require CG-7 pressure relief devices (PRDs). The issue is gaining attention as contractors prepare for broader adoption of A2L refrigerants such as R-32 and R-454B.
Here’s What Contractors Need to Know
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Under the current 2011 14th edition of CGA S-1.1, DOT regulations allow either a CG-1 rupture disk or CG-7 PRD for R-32 in DOT-39 cylinders;
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For other A2L refrigerants not listed in the CGA tables, regulations require the use of a CG-7 PRD under 49 CFR §173.304a(3).
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In March 2024, the Compressed Gas Association (CGA) petitioned DOT to update federal regulations by incorporating the 2022 16th edition of S-1.1, which specifies CG-7 PRDs with Note BB for many A2L refrigerants in DOT-39 cylinders. DOT has acknowledged the petition and said it “merits future rulemaking.”
That means the current code allows both devices in limited cases, but the industry is already moving toward standardizing on CG-7 as the safest and most compliant option.
Joe Giannetti, general manager of cooling, construction and fire suppression, Building Products, Worthington Enterprises, issued the following statement regarding the issue:
“The safety of HVACR contractors, distributors and end-users remains our top priority. Based on a growing number of questions from the market, we want to restate our position regarding the safe packaging of Class A2L refrigerant gases. We believe that all Division 2.1 flammable gases packaged in DOT-39 cylinders should be designed with CG-7 pressure release devices (PRDs) to help ensure the highest level of safety and compliance for our customers and the HVACR industry. We are confident that our regulatory agencies and industry partners will publish expanded listings and clarified requirements. In anticipation of these changes, we advise the industry to verify that DOT-39 cylinders containing Class A2L refrigerants are equipped with CG-7 PRDs.”
What This Means for Contractors
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If you’re handling R-32 in DOT-39 cylinders, both CG-1 and CG-7 may still be seen on the market — but CG-7 is the preferred, future-proof device.
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To minimize risk and stay ahead of regulatory updates, contractors should check their refrigerant cylinders and confirm CG-7 PRDs are installed before use.
The move toward universal CG-7 adoption is designed to reduce confusion in the market and ensure maximum safety as the transition to lower-GWP A2L refrigerants accelerates.
