Mixing Valves & Cancer

Does anyone have more information about this postulated relationship between mixing valves and cancer?
I haven’t been able to find much other than disclaimers on the bottom of valve spec sheets.

I looked up the specs for 5 different mixing valves. The word “cancer” did not appear anywhere within any of the documents.

Please provide more info for research. Brand, type of valve, exact wording from warning label.


Just go to Google and enter “mixing valve cancer”.

Are you talking about the State of California Prop 65 cancer warning? If they could attach that warning to air, they would. Everything causes cancer in California. Just look at the list.

This is what were down to?
I would like to see that one in the report. Dud you better learn to focus on important stuff. How the hell could a water mixing valve cause cancer? I bet I have a better chance getting it from the sun.

OK guys I’m lost here. Mixing valve for what?
Some kind of chemicals?

I believe he was referring to mixing valves used in homes for tempering of hot water in showers / baths. At least that is what I thought he meant.

Mixing hot and cold water causes cancer ?

Guess we are all dead then .

Now, a case could be made for risk of Legionnaires’ disease…


Yes, those are the ones. Here’s the warning from one manufacturer:

“Warning: This product contains an element
known to the State of California to cause cancer
of reproductive harm.”

Many other mixing valve spec sheets carry the same warning.
It would be nice to hear from one of our California colleagues if this is really an issue down there.


Going by that one should only take a cold water bath.
Give me a break.