Shein and Temu, two Chinese e-commerce giants, are the targets of a proposed investigation by the United States government into the sale of “deadly products for babies and toddlers.”

As CNNbusiness reports, the two heads of the Consumer Product Safety Commission said in an open letter Wednesday that they want the commission’s staff to examine whether the two companies are complying with U.S. safety regulations.

Noting “recent media reports” that dangerous products sold to children are easy to find on those sites, CPSC commissioners Peter Feldman and Douglas Dziak said they want to “better understand these companies, particularly their focus on low-value direct-to-consumer shipments.”

A particular concern for the commission is the companies’ use of “de minimis,” a rule that exempts shipments of $800 or less from tariffs. Much of the goods sold at Shein and Temu are inexpensive, ranging from furniture to fast fashion.

“As the Commission sets its priorities for the coming year, we expect agency staff to investigate the companies’ safety and compliance controls, relationships with third-party vendors and consumers, and any representations they make when products are imported,” Feldman and Dziak wrote.

Shein told CNN that customer safety is our “highest priority and we are investing millions of dollars to strengthen our compliance programs.” Temu said it “requires all vendors on our platform to comply with applicable laws and regulations, including those related to product safety.”

As the two companies grow in popularity, particularly in the US, they are in the sights of regulators and are being asked to answer a number of questions about how they are able to sell goods at such staggeringly low prices, how transparent they are with the public and how much environmental waste their businesses produce.

Last year, a U.S. congressional committee named Shein and Temu in a report that suggested these companies and others in China may be linked to the use of forced labor, exploitation of trade loopholes, product safety risks or intellectual property theft.