The U.S. FDA announced that it has cleared a new set of tubes used in hemodialysis machines made by Fresenius Medical Care AG & Co., of Bad Homburg, Germany, that are expected to overcome concerns about the previous tubes’ release of potentially toxic biphenyls. The agency acknowledged that it has no reports of adverse events related to the use of these chemicals in the silicone used to manufacture the tubes, stating that its action on this issue is driven solely by animal studies in the medical literature, none of which were cited in the FDA’s Oct. 28 announcement.