While a number of things have been smuggled across the U.S. border, greenhouse gases are generally not among them. That is, until March 4, 2024, when a California man decided to try it and became the first in the nation to be arrested for smuggling hydrofluorocarbons (HFCs) into the United States, according to a recent New York Times article. This, according to the United States Attorney’s Office for the Southern District of California, is a felony offense.

Per the American Innovation in Manufacturing (AIM) Act, on January 1, 2022, the U.S. began its phasedown of HFC refrigerants — such as R-410A and R-404A — that reduced the production of HFC refrigerant by 10%. The AIM Act has tasked the Environmental Protection Agency (EPA) with reducing the production, import, and usage of HFCs by 85% by 2036. To reach that goal, another refrigerant transition was set into motion on January 1, 2024. This one reduces HFC production by 60% by continuing the phasedown of refrigerants with high global warming potential (GWP) and flammability (like R-410A and R-404A) and transitioning to lower-GWP alternatives such as R-32 and R-454B, which are only mildly flammable.

Starting on January 1, 2026, a 700-GWP limit will be required for many types of new residential and light commercial a/c equipment.

To some, this might make HFCs seem like a cash cow of sorts. Especially someone like Michael Hart, 58, who smuggled and then sold canisters of banned HFCs. Many before Hart have participated in these illicit HFCs, posting ads offering canisters of HFC refrigerants and even, in some cases, HCFCs, which Hart’s indictment also alleges Hart imported — specifically HCFC-22.

Since 2020, the U.S. has banned imports of HFCs without EPA authorization, and since then, environmental regulators and investigators have warned of an illicit global trade in phased-out HFCs, They’ve been especially wary considering what happened in the European Union (EU); in 2019 and 2020, EU authorities seized over 250 metric tons of illicit HFCs. The EU began its phasedown of HFCs in 2015.

Banned refrigerant can be sold online for hundreds of dollars.

Hart is accused of purchasing coolants in Mexico and smuggling them over the border by way of his vehicle, hidden underneath a tarp and tools. He then posted the refrigerants for sale on Facebook Marketplace and OfferUp, among other sites, and sold them for a profit, according to federal agents. He faces charges of conspiracy, and importation and sale of merchandise contrary to the law.

“This is the first time the Department of Justice is prosecuting someone for illegally importing greenhouse gases, and it will not be the last,” Tara McGrath, a U.S. attorney, said in a statement. “We are using every means possible to protect our planet from the harm caused by toxic pollutants, including bringing criminal charges.”

Hart is facing a maximum penalty of five years in prison and a $250,000 fine for conspiracy, and an additional maximum penalty of 20 years in prison as well as $250,000 for the other two counts of charges brought against him.

David M. Uhlmann, head of enforcement at the EPA, said in a statement that the illegal smuggling of these gases “undermines international efforts to combat climate change.”