Handling coolants like those used in air conditioners, food refrigeration, and other systems can be a complex challenge. Workers specifically involved in the cold food supply chain industry must understand how to safely handle and store these dangerous chemicals, including those designated as A2L refrigerants.
New international agreements related to acceptable refrigerants have emerged due to recent regulatory changes to minimize ozone depletion and global warming. As companies phase out older refrigerants, they face new challenges and hazards from the replacement chemicals. For those working in the refrigeration and heating, ventilation, and air conditioning industries, building awareness of these hazards and developing best practices for their use and storage must be a priority.
What Does an A2L Designation Mean?
Every refrigerant is rated and labeled based on the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 34 designation and classification system. The rating uses a letter to indicate toxicity and a number to rate the flammability of each gas:
- Toxicity: A—Lower toxicity; B—Higher toxicity.
- Flammability: 1— no flame propagation; 2L—lower burning velocity equal to or less than 10 centimeters per second; 2— lower flammability; 3—higher flammability.
The main difference between A1 refrigerants and A2L refrigerants is the ability to propagate a flame. A2L refrigerants will burn, but with a lower velocity than A3 refrigerants, which can burn explosively when ignited. Practically speaking, even though A2L gases are difficult to ignite, precautions are necessary when handling, storing, and transporting these chemicals.
A2L Refrigerants Regulation in the United States
Flammable refrigerants are relatively new to the cold food supply chain in the United States, but they have been used safely in other parts of the world for years. Currently, there is no federal framework for regulating the use of refrigerants. While the U.S. Environmental Protection Agency (EPA) attempted to implement Significant New Alternatives Policy (SNAP) rules 20 and 21, these regulations were vacated by the U.S. Court of Appeals for the District of Columbia Circuit because it determined that the EPA did not have congressional authority.
Flammable refrigerants are relatively new to the cold food supply chain in the United States, but they have been used safely in other parts of the world for years.
This absence of federal regulations has driven some states to implement their own policies. As a result, regulatory requirements vary from state to state. Several organizations, such as the Air-Conditioning, Heating and Refrigeration Institute, ASHRAE, and the United States Department of Energy (DOE), are collaborating to explore potential hazards and recommend standards and codes. Federal policies and regulations are anticipated, with most people only questioning when they might be implemented; it’s not a question of “if,” only “when.”
Despite the lack of official federal regulations, multiple standards have been developed. The most widely adopted is ASHRAE’s Standard 15, published in 2019. The ASHRAE 15 requirements establish safeguards for life, health, and property through the recommendations for handling A2L refrigerants. They also address building code requirements for commercial and industrial applications using A2L refrigerants.
Working Considerations for Managing A2L Refrigerants
Even though there are no federal laws mandating specific processes for working with A2L refrigerants, it’s imperative to follow all best practices and recommendations to maintain a safe working environment. Companies must:
- Ensure that all relief and purge vent piping is routed outdoors and away from all air intakes per local, state, national, and international codes.
- Ensure that the area is well ventilated; if auxiliary ventilation is recommended, such as blowers or fans that disperse refrigerant vapors, ensure that it is rated for A2L refrigerants.
- Employ oxygen testing equipment and leak detection monitors to identify potentially hazardous leaks and ensure that adequate oxygen is present.
- Review the safety data sheet (SDS) when working with refrigerants; follow any recommendations and don the appropriate personal protective equipment (PPE), such as gloves and eyewear.
- Use equipment and tools certified for use with A2L flammable refrigerants.
- Ensure that a dry powder class B fire extinguisher is accessible.
- Check the area for obvious sources of sparks or flames before beginning work on equipment that uses A2L refrigerants.
- Refrain from operating appliances that use open flames or igniters or have hot surfaces while servicing these appliances.
- Take care to prevent damage to the appliance, and especially the refrigerant lines, if moving equipment containing A2L refrigerant.
- Immediately ventilate the room, evacuate the area, notify those in the vicinity, and wait until the device reads a safe level before returning if the gas leak detector reports the presence of a leak.
- Purge refrigerant lines with oxygen-free dry nitrogen before and after a repair.
- Ensure the equipment is properly grounded if the system is in operation while replacing the refrigerant.
- Follow all manufacturer’s recommendations when replacing the refrigerant.
- Follow these steps during transportation of A2L refrigerant:
- Ensure that a dry powder class B fire extinguisher is available on the vehicle.
- Review all local, state, and federal regulations applicable in the jurisdiction of transport.
- Do not store refrigerant cylinders near heat or a source of ignition.
- Label all refrigerant cylinders following the guidelines in US 49 CFR part 172.417.
- Secure flammable refrigerant cylinders to prevent theft, tampering, or movement during transport.
ASHRAE 15 also outlines requirements for leak detection monitors. Clause 220.127.116.11 states:
Each refrigerating machinery room shall contain a detector, located in an area where refrigerant from a leak will concentrate, that actuates an alarm and mechanical ventilation in accordance with Section 8.11.4 at a value not greater than the corresponding TLV-TWA (or toxicity measure consistent therewith). The alarm shall annunciate visual and audible alarms inside the refrigerating machinery room and outside each entrance to the refrigerating machinery room.
When identifying an optimal refrigerant leak detection sensor, there are several factors to consider, including:
- Speed. To address leaks quickly and ensure a safe workplace, you need a detector that can quickly alert you of a leak so that your response can be just as quick.
- Ease of use. A good detector should be easy to use and to understand to prevent you from fumbling with it while hazardous conditions are present.
- Accuracy. Accuracy is essential, although it can be difficult to obtain when there is low oxygen, high humidity, and/or multiple gases in an environment. Identify a multi-gas sensor that works under all potential environmental conditions that may exist in your workplace.
- Total cost of ownership. Initial cost is important, but don’t forget to consider additional calibration or replacement costs when determining the total cost of ownership.
Reviewing these factors when looking for a gas leak detector helps ensure leaks are detected quickly and the workplace remains safe when an A2L refrigerant is being used.
Christensen is senior director of business development at NevadaNano.