Refrigerant regulations in the USA: What applies to freeze drying

Exception for “very low temperature refrigeration”

An exception continues to apply for applications with process temperatures below –50°C: The use of HFC refrigerants such as R410A is possible provided that the refrigerant is approved by the US Environmental Protection Agency (EPA). This regulation particularly affects freeze dryers that reach extremely low temperatures.

AIM Act: Strict requirements for all other applications

Regardless of the application temperature, the AIM Act provides for significant restrictions. Since 2025, certain refrigerants have been banned or strictly controlled in most applications. The requirements apply to, among other things:

• new refrigeration systems,
   
• the installation, import, and sale of prohibited HFCs
   
• and, in the future, many service applications.

For freeze-drying systems, this means that the use of conventional HFCs is only permitted in exceptional cases—especially at temperatures below –50°C. Stricter regulations already apply to all other applications.

Optima recommends a forward-looking, technology-neutral approach when selecting cooling systems for freeze dryers. For systems that reach extremely low temperatures (below –50 °C), the use of HFC refrigerants such as R410A is still possible at present. Nevertheless, it should be borne in mind that this exception may also be abolished in the future.

Optima therefore recommends that new projects always use alternative cooling solutions that are designed independently of short-term exemptions. The following have proven particularly effective:

• Cascade systems with natural refrigerants (e.g., ethane and propene) that are technically mature and implemented in accordance with safety requirements.
   
• Systems with liquid nitrogen (LN₂), which are based on physically proven principles and reliably achieve low temperatures.
   
• Cold air systems, which are an environmentally friendly solution for particularly demanding applications.

These technologies enable customers to secure their investments in the long term, minimize regulatory risks, and make an active contribution to climate protection—without compromising on performance or process reliability.

Optima supports its customers with comprehensive advice, from technical design and selection of the appropriate cooling solution to regulatory assessment of the target country.