It's just been announced by the Department of Health that the
chemicals used in the manufacture of PEX pipe cause cancer when these
pipes are used for drinking water. The chemicals leech into the water
and accumulate in the body. This is particularly evident for hot
water, since the heat extrudes the carcinogen more than cold water.
PEX pipe will likely be banned nationwide by the end of 2010. They
warn that if you have PEX pipe in your home, DO NOT drink the water,
or use the water for cooking. Boiling the water only concentrates the
harmful chemicals, so boiling will not make the water safe. Worse yet
are those homes who have chlorinated water. The chlorine in the water
is causing these harmful chemicals to leech into the water as much as
five times the concentrations above that of standard water.
The best solution is to remove all PEX pipes from your homes and
businesses and replace them with copper, steel, or other conventional
plumbing. If you do replace the PEX pipes, be sure to drain and
thoroughly flush your hot water heater, since heavy concentrations of
the harmful chemicals will remain in the tank.