Polybutylene toilet risers

Q: I am aware that the use of polybutylene water piping has been banned in most jurisdictions. However, when purchasing toilet and sink supply tubes recently, I noticed that these parts are available in polybutylene, in addition to the standard copper and braided-metal covered hose types. Why is this type of piping still allowed for this application?

A: Rex Cauldwell, a writer and a plumbing and electrical contractor from Copper Hill, Virginia, replies: Because of well-publicized problems, polybutylene pipe is no longer sold in the United States and should not be used for any type of plumbing. However, you may have seen some leftover polybutylene stock that your hardware store hadn’t gotten rid of yet. I still see polybutylene pipe and risers on occasion in some of the hardware stores near where I live. It is also possible that the risers you saw were PEX pipe, which is a different type of plastic pipe, with a gray coloring.