lead content of brass

[bricktron]

hi folks, i have been building my tub setup using, in part, 3/4" brass valves, flow meter, fittings, and so on. nearing the end of the build i was alarmed to find that a nipple i bought was labelled unsafe for drinking water. this may be a direct consequence of my living in california. in any case, this paper describes the surprisingly varying levels of lead in brass plumbing fittings. unfortunately, i already bought rather a lot of brass fittings without ever noticing that they had different levels of lead. this leads me to believe i should either presume the worst (8% Pb) or replace everything. i realize the tub water is not for ingestion, but there are children involved.

what levels of lead in fittings are considered safe for bathing? (not sure if this is the same for swimming and hot baths.)

 

[JoyfulNoise]

Swimming pools and hot tubs are very different than household bathtubs as your recreational water will use lots of different chemicals that can cause both oxidation and pH changes. Most folks either use chlorine or bromine to sanitize their hot tubs and the chemicals used will cause pH changes. Water pH needs to be constantly tested and adjusted which means adding acids (most of the time) and bases (not very often). Any of these chemical additions can lead to fluctuations in pH which, for brief periods of time can take the water well outside of it's average values. Building a hot tub out of metal plumbing components is not really the best choice and is why most manufacturers use PVC components. Even if lead were not present, copper can be easily leached from brass fittings and pipes and cause all sorts of water problems.

So there's no easy answer to your question. I would say that any level of lead is unsafe. Now there are plenty of old homes with copper pipes in them that have old lead-tin solder joints that people have used for decades without issue. However, the recent experiences of the Flint Drinking Water Crisis should give everyone pause at how easily water can become contaminated with metals when improper chemistry is employed.