A Hidden Lead Source Many Never Think About
Everyone expects to find lead in old paint. Few realize that lead has also historically been used in the zinc coating applied to galvanized steel—the dull gray metal found almost everywhere in our everyday environment.
Why Is There Lead in Galvanized Steel?
Traditionally, steel was galvanized by dipping it into a bath of molten zinc. Historically, that zinc could frequently contain lead.
In lower purity zinc, the lead was naturally present. Other times, it was intentionally added to improve the behavior of the molten zinc during the galvanizing process (it’s a cruel joke that lead is useful in SO many applications, isn’t it?). Lead helped the zinc flow more evenly, drain more cleanly, and produce a smoother finished coating.
As a result, many galvanized products manufactured over the past century contain measurable amounts of lead within the zinc coating itself.
In a 2015 study, researchers from Virginia Tech noted that galvanizing zinc historically contained lead concentrations of approximately 0.5% or more in many applications. That might not seem like a lot, but for lead, it’s far more than you would want to see in an every-day object.
Galvanized Steel Erodes
Rather than existing as a separate layer, the lead becomes incorporated into the galvanized coating and remains there…until, of course, the metal begins to deteriorate.
This deterioration is actually by design—Instead of allowing the steel underneath to rust, the zinc slowly oxidizes first.
Over months, years, and decades, rain, sunlight, changing temperatures, abrasion, pollution, and normal weathering gradually wear away portions of the zinc coating. As this happens, corrosion products form on the surface.
If the galvanized coating contains lead, the corrosion byproducts can also contain lead.
IMPORTANT: Not All Galvanized Steel Contains the Same Amount of Lead
Two galvanized objects can have dramatically different lead concentrations depending on:
When they were manufactured
The purity of the zinc used
The galvanizing process
The manufacturer
The country of origin
Whether recycled zinc was used
Whether the object has additional coatings or paint
Modern galvanizing operations typically use much higher-purity zinc than was common historically. And not all older galvanized steel contains lead either. It’s highly dependent on the individual manufacturer’s preferences.
The only reliable way to know whether a particular galvanized object contains lead is to test it.
The Big Picture
Galvanized steel is used so often precisely because it survives extremely well outdoors…but this means it is exposed to the constant weathering, and repeated handling that causes gradual surface wear. It’s this wear that causes lead exposure.
Think about how often we interact with galvanized steel every day…
Children climb on galvanized playground equipment, people touch galvanized railings, people lean on galvanized fencing, gardeners use galvanized planters and raised beds…people use galvanized gates, hardware, and outdoor fixtures every day.
Intact galvanized steel is generally a much lower-risk scenario than deteriorating lead paint, however, it’s still not something I think that people should touch. Especially young children—who frequently place their hands in their mouths. Even small amounts of lead transferred from environmental surfaces can contribute to cumulative exposure over time (check out the Lead in Body course for a deeper dive there).
Galvanized steel isn't usually included on lists of common lead sources, yet it's one of the most widespread building materials in the modern environment.
Understanding that possibility doesn't mean avoiding every galvanized object. It means recognizing that lead exists in more places than most people realize, and that cumulative exposure often comes from many small sources rather than one obvious one.
As we continue learning about environmental lead, galvanized steel deserves a place in the conversation alongside paint, soil, water, ceramics, and consumer products—not because every galvanized surface is dangerous, but because the zinc coating itself has historically been another overlooked source of lead.
References
Clark BN, Masters SV, Edwards MA. Lead Release to Drinking Water from Galvanized Steel Pipe Coatings. Environmental Engineering Science. 2015.
U.S. Consumer Product Safety Commission. Total Lead Content Requirements for Children's Products.
Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Lead.
World Health Organization. Lead Poisoning and Health.