Valsartan, a drug used to treat high-blood pressure and prevent heart failure, was recalled in 22 countries across Europe and North America earlier in July after batches were found to contain N-nitrosodimethylamine (NDMA), an organic chemical that belongs to a family of potent carcinogens.

The substances were supplied by Zhejiang Huahai Pharmaceuticals (ZHP), based in Linhai, in eastern China,