U.S. regulators keeping eye on low-charge systems

U.S. facilities with 10,000 lbs. (4535.9 kg) or more of an ammonia refrigerant face greater regulatory requirements under the Environmental Protection Agency’s (EPA) Risk Management Plan (RMP) and the Occupational Safety and Health Administration’s Process Safety Management (PSM) program.

But what is the case for other ammonia systems with less than 10,000 lbs. of ammonia charge, including many of the new low-charge ammonia systems? How much scrutiny do they face under the agencies’ less restrictive General Duty Clause?

“Both agencies are trying to apply PSM- or RMP-like requirements to facilities under 10,000 lbs.,” said Randel.

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Mixed signals on low-charge systems

If a company runs some facilities with more than 10,000 lbs. of ammonia, and others with less than 10,000 lbs., the agencies will expect the latter “to apply the same hazard reduction principles” as the former, Randel said.

Overall, though, the regulatory burden does lessen with a charge below the 10,000 lbs. mark.

“Your reporting and documentation requirements are a lot less, and you’re not subject to programmed inspections,” said Randel. Moreover, a 500-lb. system will present a much different type of hazard protocol than a 9,000-lb. system, even though both are under 10,000 lbs.

Still, the EPA or OSHA can inspect the premises as part of a check-up or due to an accident or complaint. “And once an agency is inside your building, they are going to want you to address the same kinds of hazards in the general duty clause as in RMP/PSM facilities.”

Randel said that industry associations are meeting with the agencies to discuss low-charge ammonia systems and the lesser hazards that they present. “They’re listening; they understand the hazards are different,” he said. “But they say there are still some of the same hazards as in larger systems.”

The International Institute of Ammonia Refrigeration (IIAR) has an ammonia resources manual (ARM) that offers general-duty clause guidance to ammonia refrigeration operators.

The organization is now looking at developing a similar manual for low-charge systems with 500 lbs. (226.8kg) or less of ammonia – an “ARM-light,” said Randel. “We’re hoping down the road, if people follow that manual, they would be meeting the general-duty clause. But we’ve got a ways to go.”