A federal safety agency warned this week that small, powerful magnets have been linked to seven deaths after they were ingested, announcing one company’s voluntary recall of a set that contained such magnets and issuing warnings about six other companies with similar products.

The agency, the U.S. Consumer Product Safety Commission, said on Thursday that it was aware of seven deaths, including two outside of the United States, and about 2,400 emergency-room visits between 2017 and 2021 linked to ingesting the small, high-powered magnets.

The danger is that they could easily attach with magnets or other metal objects, making them an even greater hazard if swallowed along with another object. Even swallowed alone, the small magnetic balls pose a risk of perforation to or blockage of the intestines, blood poisoning or death, the commission said.

Last year, the commission approved a new safety standard for small magnets, requiring that products be either too large to swallow or weak enough to reduce the risk of internal injuries when swallowed.

During tests, the magnets, which are made of rare earth metals and measure five millimeters, or roughly the size of a pea, fit within the commission’s small parts cylinder, which is approximately the size of a fully expanded throat of a child under 3.

At least seven companies this year were selling products that failed to meet the new standard. Those companies were not linked to the deaths or injuries, said Patty Davis, a commission spokeswoman.

The commission provided no additional information about the names of the companies that made the products linked to the deaths and injuries.

The commission tested the products, some of which are small, separate metal balls that can be sculpted into shapes, and found that the magnets were too small, too strong or both, Ms. Davis said.

“If you have kids in your house, these can be deadly,” she said.

One company, XpressGoods of Raleigh, N.C., recalled and offered refunds for a set of colorful, small magnets it had sold as Neodymium Magic Magnetic Balls. The recall affected about 700 units sold online between July 2021 and May 2022. The company could not be reached for comment on Friday.

The commission warned consumers against these other products: SplishSplashFun’s SplishSplash Balls Reusable Water Balloons; MXN Commerce Inc.’s Carrara Magnet Ball Sets; Magic QQ’s 216-Piece Mixed Color Magnetic Ball Sets; Ming Tai Trade’s 216-Piece 5mm Magnetic Ball Sets; Sunny House’s 125-Piece 5mm Mixed Color Magnetic Ball Sets and Allvre’s 216-Piece 5mm Magnetic Ball Sets.

“These companies refused to do recalls so we’re going directly to consumers,” Ms. Davis said. “You need to stop using them immediately. Throw them away.”

SplishSplashFun’s website was down and the company could not be immediately reached. MXN Commerce Inc. did not immediately respond to a request for comment. No contact information could be found for Magic QQ, Allvre or Ming Tai Trade, all companies based in China, according to the commission.

On Temu, the popular Chinese shopping platform, Sunny House’s products page was down on Friday.

In a statement on Monday, Temu said that it removed the products from its platform after receiving notice from the commission. When the sellers failed to issue a recall, Temu “immediately decided to ban the merchants from our platform permanently” and offered refunds to affected customers, the statement said.

Beyond issuing warnings to consumers, the commission can sue or begin a mandatory recall process, but that can take years.

In 2021, the agency enforced a mandatory recall of a set produced by Zen Magnets LLC after two children required surgery to remove ingested magnets that were lodged so deeply that parts of their intestines and bowels had to be removed.