(Yicai Global) Jan. 9 -- Huahai Pharmaceutical, a Chinese company that makes and sells generic drugs worldwide, has started recalling certain drug ingredients sold to Europe and the US from 2015 to last year after batches were found to contain an excessive amount of probable cancer-causing impurities.

N-nitrosodiethylamine, or NDEA, a carcinogenic impurity, was discovered in 27 batches of hypotensive ingredients worth CNY9 million (USD1.3 million), the Linhai, Zhejiang province-based company said today.

The European Medicines Agency said last July that it had found a carcinogen called N-nitrosodimethylamine, or NDMA, in Huahai's high blood pressure treatment valsartan. European countries immediately demanded a product withdrawal. Shortly afterwards, the firm issued a recall of the medicine across the US and China and warned its investors of likely lawsuit risks.

In a risk-prevention measure, Huahai Pharmaceutical inspected its valsartan products sold both at home and abroad from 2015 to last year for impurities encompassing NDMA and NDEA, it said today. The firm disclosed that 1,080 batches sold in China met national standards, but 27 of the 1,163 batches sold to Europe and the US exceeded tolerable limits.

NDEA naturally exists in certain foods, drinking water, polluted air and industrial processes. NDMA and NDEA are classified as Group 2A carcinogens by the World Health Organization's International Agency for Research on Cancer. Group 2A carcinogens probably cause cancer in people based on limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals.

Three of the 27 batches were used in the production of irbesartan preparations in the US, and the remaining 24 batches were sold to foreign pharmaceutical preparation firms, Huahai said.

The firm's US subsidiary will recall the preparations made from the three unqualified batches of irbesartan active pharmaceutical ingredients after confirmation with the US Food and Drug Administration. The firm has notified the buyers of the remaining batches of the test results and will carry out a recall.