Washington, D.C. ? A second American company recalled Heparin products Friday as China announced it was clamping down on production of the blood-thinning drug’s main ingredient to prevent further cases of contamination.

B. Braun Medical Inc. withdrew 23 lots of Heparin products after learning it received a contaminated ingredient. The Bethlehem, Pa., company described the recall as precautionary. It said it had not received any reports of side effects, even though the suspect lots have been sold in the United States and Canada.

The products are intravenous-solution bags used for patients who need low doses of Heparin during hospital stays, said the U.S. Food and Drug Administration.

B. Braun is a relatively small Heparin seller with one-tenth of the market for the premixed bags, a company spokeswoman said. It is still making the product since just one lot of supplies was contaminated, the FDA said.