Many fidget spinners have "button batteries" that make the toys light up as they spin, according to the EU's Rapid Alert System for Dangerous Product 2017 Annual Report. If children swallow these "small, flat batteries" they can "cause burns to the [esophagus] and intestines."
Button batteries are not the only concern the commission cites. Fidget spinners often have "easily detachable small parts," such as the central cover of the toy, according to the report.
"This can pose a risk, especially to small children, who may put it in the mouth and choke," the report said. In these cases, the report said hospital intervention is needed quickly.
The report said that as a result of the EU's Rapid Alert system "dangerous fidget spinners have been tracked down, stopped at borders andports, or destroyed."
The Consumer Product Safety Commission in the U.S. has also issued warnings about the hazards of fidget spinners, including choking, and some were recalled by Target stores over concerns they may have contained lead.