The Dutch junior health minister Tamara van Ark has launched an investigation after tests by the NRC and television programme Zembla claims that some types of paracetamol sold in the Netherlands could be contaminated by a carcinogen.

Investigators asked a laboratory in Germany to test samples from three batches of the active pharmaceutical ingredient of paracetamol made by Anqiu Lu-an Pharmaceutical, the world’s largest producer. The batches, made in spring 2019, were reportedly enough to make 36 million pills but it is not known where in the world they were to have been sold.

The investigators claim that all three batches were contaminated with 4-choloroaniline (PCA), a potentially genotoxic substance that has been linked with liver tumours in test animals. Different European regulators apparently have different risk assessments for the substance and accept different levels, the NRC reported.

Guidelines from the European Medicines Agency suggest that up to six contaminated tablets a day would be a ‘tolerable daily intake’, based on its accepted levels. But the European Food Safety Authority accepts lower norms, and investigators said that the concentrations found in the samples were 18 times these levels. They suggested that one contaminated pill a day ‘may already lead to an unacceptable risk of cancer’ according to these tougher limits.

Van Ark said on Friday that she understood that people would be worried by the reports, although the information she had seen suggested contamination levels were within the norms. ‘However the inspection will be researching whether there is anything behind these signals,’ she told public broadcaster NOS. ‘I think this is very important because people should be able to assume that medicine is safe.’

Professor Jan Tytgat, toxicologist at KU Leuven in Belgium told Zembla and the NRC he believed regulators should trace and recall the contaminated batches, and that other factories using the same production method should be tested. ‘Above the [EFSA safety margin], there is a substantiated risk that PCA is carcinogenic,’ he reportedly said. ‘PCA does not belong in a painkiller used by so many people.’

The NRC claimed that Anqui Lu-an Pharmaceutical’s products are used by companies that produce own-brand products for leading Dutch retailers. The report claimed that there was an alternative production process for the active ingredient in paracetamol which does not produce PCA, used by American company Mallinckrodt.

The Dutch Medicines Evaluation Board responded to the investigators that levels of PCA in the samples fell ‘well below’ the threshold set by the European Medicines Agency, and said the substance was only ‘possibly carcinogenic’.

DutchNews.nl has contacted Anqiu Lu-an Pharmaceutical to ask for a comment.