ScieGen Pharmaceuticals has issued a recall of the blood pressure drug irbesartan after lab testing revealed a carcinogenic impurity, the FDA announced in a MedWatch Safety Alert.

The recall includes 75 mg, 150 mg and 300 mg dosages of the drug, which were manufactured by ScieGen but are labeled as Westminster Pharmaceuticals or Golden State Medical Supply. The FDA estimates 1 percent of irbesartan in the U.S. is subject to the voluntary recall.

ScieGen took action after certain lots of the drug were found to contain N-nitrosodiethlamine (NDEA), which has been classified as a probable human carcinogen by the International Agency for Research on Cancer. NDEA can occur naturally during the manufacturing process.

Irbesartan is the second angiotensin II receptor blocker to make headlines recently for being tainted with possible carcinogens. Medications containing valsartan were recalled in more than 20 countries—including the U.S.—beginning in July after they were found to contain N-Nitrosodimethylamine (NDMA).

The FDA said patients could identify the recalled irbesartan tablets and return them to their pharmacy after finding an alternative treatment with the help of a healthcare provider. The products are white, oval-shaped and marked with SG 160, SG 161 or SG 162, although the FDA also lists lot numbers, expiration dates and photos of medication labels to help consumers and pharmacists determine if their products might be contaminated.

However, the FDA suggested patients should continue taking the medication until they find another option, “as the risk of harm to a patient’s health may be higher if the treatment is stopped immediately without any alternative treatment.”