Drinking water from plastic pipes: Is it harmful? — ScienceDaily

Pipe-in-pipe systems are now commonly used to distribute water in many Norwegian homes. The inner pipe for drinking water is made of a plastic called cross-linked polyethylene (PEX). Are these pipes harmful to health and do they affect the taste and odour of drinking water? Previous international studies have shown that plastic pipes can release substances that give an unwanted taste and odour to drinking water. It has also been suggested that some of these substances may be carcinogenic. The aim of the study by the Norwegian Institute of Public Health was to investigate whether leakage products from these pipes are harmful to health and if they affect the taste and odour of drinking water. These leakage products consist of residues of additives used during production to give plastic pipes their desired properties, as well as any subsequent breakdown products. Ten different types of PEX pipes available in the Norwegian market were tested for leaching products in a standardised laboratory test. The water was in contact with the tubes for 72 hours. Three different manufacturing methods produce pipes known as PEX-a, PEX-b or PEX-c. These methods use slightly different additives, bu...