Stores in Washington D.C., Philadelphia, New York and other cities remain fully stocked with the brightly colored vapes, sold in fruity flavors like strawberry melon and claiming to contain 5,000 “puffs” per device.

The Food and Drug Administration considers the products illegal. In May, it directed customs officials to seize incoming shipments of Elf Bar and EBDesign, two of the company’s U.S. brand names.

The newer vaping devices bear a different name, EBCreate, and list different Chinese manufacturers than those targeted by the FDA.

The makeover underscores the FDA’s inability to stanch the flow of unauthorized e-cigarettes into the U.S., mainly through large shipping hubs like Los Angeles and Houston.

“E-cigarette manufacturers have proven themselves to not operate in good faith,” said Desmond Jenson, an attorney at the Public Health Law Center. “Until there’s something global that’s a deterrent to selling illegal products this is going to be the status quo.”

Jenson’s group and others have urged the FDA to require unique identification codes on all FDA-regulated tobacco products, which would allow customs to spot and seize illegal products. But the FDA has never proposed such a system, despite receiving the authority from Congress nearly 15 years ago.

FDA’s tobacco director, Brian King, said the agency is monitoring instances where companies try to avoid detection by changing their branding.

“The public and importers of e-cigarettes should be aware that the FDA has a variety of tools at our disposal to take action against these tactics,” King said in a statement. He noted the agency can, and does, add new brands and product types to its import alerts.

The Associated Press reported in June that the number of unique e-cigarettes on the market has tripled to over 9,000 since 2020, a surge driven almost entirely by Chinese-manufactured disposables. Most come in candy and fruit flavors that have made them the favorite tobacco product among teens.

Elf Bar generated U.S. sales of over $271 million in the past year, according to retail data tracker Nielsen. Separate data previously obtained by the AP shows the brand hit U.S. stores in November 2021 racking up hundreds of millions in sales over 18 months before being targeted by FDA regulators.

Public records show how quickly Elf Bar was able to rebrand itself when the FDA announced its import ban in May.

Two weeks later, a request to trademark EBCreate was filed with the U.S. Patent and Trademark Office. The filing was made by the same patent attorney who submitted Elf Bar’s previous applications. But unlike those filings, the paperwork doesn’t mention Elf Bar’s parent company, iMiracle Shenzhen Technology. Instead the application lists a Hong Kong company, Nevera HK Limited, the same company listed on new EBCreate e-cigarette packages.

The new products bear the same QR code previously found on Elf Bar packages to help customers verify their authenticity, as well as the same licensing code assigned by Chinese tobacco authorities. An e-cigarette purchased by the AP listed its manufacturing date as July 10, almost two months after the import ban.

iMiracle Shenzhen did not respond to calls and emails seeking comment.

Even when companies don’t rename their products, experts point to the challenge customs officials face in intercepting banned products among the tens of thousands of shipments arriving daily at U.S. ports.

“These items may come in under other deceptive practices. They are mislabeled or bundled together with other items in a container,” said Rob Handfield, who studies global supply chains at North Carolina State University. “Customs and Border Patrol aren’t going to go and inspect the contents of every shipping container.”

Unauthorized e-cigarettes are one small part of an influx of illicit Chinese goods.

For years, U.S. authorities have appealed to China’s government to crack down on producers of chemicals used to make fentanyl, the deadly opioid that now accounts for the majority of U.S. drug overdose deaths. Earlier this year, the Department of Justice officials announced the first charges against Chinese companies and employees for supplying the chemicals to fentanyl producers in the U.S. and Mexico.

The FDA’s main tool against e-cigarette manufacturers are warning letters, which put companies on notice for violating FDA rules but are not legally binding.

The agency has issued more than 450 warnings over the years to various vaping manufacturers. None have been sent to Elf Bar-maker iMiracle Shenzhen, which also sells Lost Mary, Funky Republic and other brands in the U.S. and internationally.

The FDA did not provide an explanation for why the company has yet to receive a warning letter. The agency noted it is still gathering data on the impact of the import ban, including numbers of products detained or turned away.

Recently the agency has targeted vape shops, gas stations and convenience stores that sell disposable e-cigarettes. Last month, the FDA said it would seek the maximum fines available under its regulations, about $19,000 each, from 22 stores. Regulators sent another 170 warning letters to stores selling Elf Bar-related products.

But an expert report commissioned last year at the FDA’s request criticized the agency’s “failure to remove products from the market.”

The FDA still hasn’t fully utilized its powers to seize inventory from stores and distributors that sell unapproved products, experts note.

“FDA has confiscated more heads of romaine lettuce than it has illegal e-cigarettes in the last five years,” said Jenson. “You have to actually be able to stop these companies from making money doing illegal things if you want to change anything.”