Thousands of homes are now using pipes-in-pipe systems to distribute water. XPE, or cross-linked polyethylene, is the material used to make the inner drinking water pipes. How do these pipes affect the taste and odor of water? Do they harm the health of the public?

Norway has now become one of the most common countries to install pipe-in-pipe systems for distributing water. It is made of a plastic called cross-linked polyethylene (PEX), which is the material used for the inner pipe of the drinking water system. Is drinking water affected by these pipes? Are they harmful to health, and do they affect the taste and odour of the Studies have previously shown that plastic pipes can give drinking water an undesirable taste and an unpleasant odor if they are at risk for leaks. In addition, some of these materials may cause cancer if they are consumed in large quantities. In the study performed by the Norwegian Institute of Public Health, the researchers examined whether leakage products from these pipes are harmful to health as well as whether they can alter the taste and odor During production of plastic pipes, additives are used in the manufacturing process to give them particular properties. At the same time, subsequent breakdown products also contribute to leakage.

As a result of the study 

PEX pipes from ten different brands and types available in the Norwegian market were tested for leaching products in a standardised lab test. Water was used in contact with the tubes for 72 hours, and they can be produced according to three different methods. While these methods use slightly different additives, there was no correlation between the production method and the leakage products in the study. In the experiments, 2.4-di-tert-butyl-phenol (DTB) and MTBE (Methyl Tert-Butyl Ether) were two of the most commonly found substances in water. MTBE was found in higher concentrations in three types of new pipes compared to those in the USA. Drinking water test tubes were used after awhile to achieve the USEPA’s recommended limits for taste and odor of drinking water. Eventually, the values fell below the limits after use.