A Wall Street Journal investigation found 4,152 items for sale on Amazon.com Inc. ’s site that have been declared unsafe by federal agencies, are deceptively labeled or are banned by federal regulators—items that big-box retailers’ policies would bar from their shelves. Among those items, at least 2,000 listings for toys and medications lacked warnings about health risks to children.

The Journal identified at least 157 items for sale that Amazon had said it banned, including sleeping mats the Food and Drug Administration warns can suffocate infants. The Journal commissioned tests of 10 children’s products it bought on Amazon, many promoted as “Amazon’s Choice.” Four failed tests based on federal safety standards, according to the testing company, including one with lead levels that exceeded federal limits.

Of the 4,152 products the Journal identified, 46% were listed as shipping from Amazon warehouses.

After the Journal brought the listings to Amazon’s attention, 57% of the 4,152 listings had their wording altered or were taken down. Amazon said that it reviewed and addressed the listings the Journal provided and that company policies require all products to comply with laws and regulations.