Galvanized-Iron Plumbing Cadmium-Zinc Leaching and Brass-Fitting Dezincification (Pre-1960 Galv Pipe Inventory, Brass Hot-Water Failure) — household safety profile
Moderate riskNot medical or professional safety advice, and not a substitute for a qualified clinician — consult one. Full disclaimer →
Galvanized-iron and galvanized-steel water-supply piping was the dominant US residential plumbing material 1880-1960, displaced by copper after WWII and by PEX after 1990.
What is this product?
Galvanized-iron and galvanized-steel water-supply piping was the dominant US residential plumbing material 1880-1960, displaced by copper after WWII and by PEX after 1990. The galvanizing process deposits a zinc coating on iron substrate; industrial-era zinc is not pure — it contains 0.1-1% cadmium as a smelter co-contaminant. Over 50-100 years of service the zinc coating corrodes through, exposing the iron substrate (red rust + reduced flow) and releasing both ZINC (secondary MCL 5 mg/L; AAP infant zinc limit 5 mg/day) and CADMIUM (EPA primary MCL 5 ug/L; renal cortical accumulation half-life 10-30 years). The cadmium pathway is the underrecognized exposure: cadmium is far more toxic than zinc, accumulates in renal cortex, and an aging galvanized line gradually shifts from zinc-dominant to iron-rust-dominant leaching, but cadmium is released throughout the corrosion lifecycle. The second exposure pattern is BRASS-FITTING DEZINCIFICATION — yellow brass (>15% Zn) is susceptible to selective leaching of zinc out of the Cu-Zn matrix, leaving a porous copper-rich structure that fails mechanically (slow leaks, sudden ruptures) and releases zinc into the water stream. Hot-water lines + chloramine treatment + soft water accelerate dezincification. Dezincification-resistant (DZR) brass alloys (CW602N, C36000 with arsenic inhibitor) and lead-free bronzes are the modern replacement standard but pre-2000 brass fittings remain in tens of millions of homes.
What's in it
Click any compound name for its full safety profile, regulatory consensus, and exposure data.
Smelter Cocontaminant
Primary Galvanic Release
Corrosion Byproduct
Brass Matrix Metal
Frequently asked questions
No FAQs generated.
Look up Galvanized-Iron Plumbing Cadmium-Zinc Leaching and Brass-Fitting Dezincification (Pre-1960 Galv Pipe Inventory, Brass Hot-Water Failure) in the home app
Search by ingredient, browse by category, or compare to alternatives in the live app.
Open in home View raw API dataReference data, not professional advice. Aggregates publicly available regulatory and scientific information. Why we built ALETHEIA →