Galvanized Welding Sickness: Causes and Prevention

It’s Monday morning, and a fabricator who welded galvanized handrail brackets all week wakes up with a fever, chills, and aching muscles that feel uncannily like the flu. He takes a sick day, feels better by Tuesday, then feels terrible again the following Monday. What nobody told him is that he was poisoned on every one of those shifts — not by bad lunch, but by zinc. That experience has a name in the trade: galvanized welding sickness.

What Galvanized Welding Sickness Actually Is

Let’s get straight to the definition, because the trade slang and the medical name mean the same thing. Galvanized welding sickness is shop-floor shorthand for metal fume fever, also called zinc fever. It is an acute, flu-like illness you get after breathing zinc oxide fume, and that fume is created when an arc, a torch or a hot tool boils the zinc coating off galvanized steel and sends it into the air you are breathing.

This is not a rare reaction to something exotic. OSHA notes that zinc oxides occur from zinc-enriched paints and from galvanized steel, and that zinc exposure is the usual cause of metal fume fever. In other words, it is the expected outcome of welding coated steel without controlling the fume.

An old condition with a pile of old names

This is not a modern occupational disease. According to StatPearls, the first reported cases date to the 1830s. Since then, the same illness has traveled through factories under a half-dozen labels: Monday fever, brass founders’ ague, welders’ ague, smelter chills and zinc shakes. If a retired foundry hand tells you he had “brass founders’ ague” in 1978, he was describing the same thing a modern fab shop calls galvanized welding sickness.

Each name hints at the pattern. “Monday fever” comes from the way symptoms follow the work week. “Smelter chills” and “zinc shakes” come from the shakiness and fever that hit after a shift near the furnace or the zinc kettle. “Welders’ ague” is the trade’s own word, and “ague” simply means an acute fever with chills.

Who actually runs into this

Welding galvanized steel is one of the most common jobs in the trade, which means metal fume fever shows up in a lot of different settings:

• Fabrication shops welding galvanizing handrail brackets, stair stringers, gusset plates and structural steel
• Structural steel erectors bolting and welding connections on galvanized bridge and building frames
• HVAC and sheet metal shops working galvanized ductwork, a large volume of coated steel in one building
• Galvanizing plants themselves, where kettle work and touch-up repair mean routine zinc exposure
• Field repair crews patching damaged galvanized members, water towers, tank shells and transmission towers
• Hobbyists and weekend fabricators, who have the least access to extraction equipment and the least training

Add anyone doing a one-off repair with a portable generator, an old garage, or an open barn door and you have covered nearly everybody who has ever welded a galvanized bracket.

How common is it, really?

The workforce is enormous. NIOSH’s engineering controls documentation states that census data indicate more than 700,000 workers in the United States are involved in welding or allied processes. That is a lot of people standing near an arc.

Cases, however, are far fewer than you might guess, and StatPearls helps explain why: it cites Bureau of Labor Statistics data showing over 420,000 persons involved in metal applications in the US in 2020, with roughly 2,000 estimated cases of metal fume fever per year. Of those, about 96 percent are men, and only about half are occupational rather than hobby or do-it-yourself exposure. That last figure matters. A meaningful slice of this illness happens in home garages and private projects where there is no industrial hygienist, no respirator program and nobody filing a report.

Those numbers also set a reassuring tone for most people. StatPearls states that more than 90 percent of metal fume fever cases are mild and self-limited, resolving in one-half to two days. In plain terms: you feel rotten, you stay in bed, you miss a shift or two, and then you are fine.

But do not mistake common and mild for harmless. Zinc is a regulated hazard under 29 CFR 1910.252, and paragraph 1910.252(c)(6) was written specifically for welding and cutting zinc-bearing base metals and zinc-coated materials. Meanwhile, long-term fume exposure carries documented consequences beyond a single fever. OSHA Fact Sheet 3647 lists metal fume fever alongside stomach ulcers, kidney damage and nervous system damage among fume-related health effects, and NIOSH notes a 40 percent increase in relative risk of lung cancer for welders. The Monday fever is the part you feel. The rest is what accumulates.

What this article covers

Three things, in order. First, what is actually happening inside your lungs when you inhale galvanized fume, and why the same weld can be safe on Monday and leave you in bed on Tuesday. Second, what OSHA requires when you weld zinc-coated steel, including the ventilation rules in 1910.252(c)(6) and the confined space rules that catch people out. Third, exactly what to do before you strike an arc: how to grind the coating off, how to position extraction, and how to pick a respirator that actually does something.

If you weld galvanized steel, even occasionally, this is worth reading all the way through.

Why Zinc Turns a Weld Into a Hazardous Job

Welding plain carbon steel is mostly a matter of amperage, wire feed, and travel speed. Welding galvanized steel is different. You’re not just joining steel, you’re putting an arc directly into a metallic coating, and once that coating gets hot enough, it becomes the source of a very real hazard.

What Hot-Dip Galvanizing Actually Is

Hot-dip galvanizing involves immersing fabricated steel into a bath of molten zinc held at roughly 450 °C (840 °F). As the steel cools, the zinc reacts with iron to create a series of iron-zinc intermetallic layers, topped by a layer of relatively pure zinc. This creates a sacrificial barrier: instead of only blocking water, the zinc will corrode in place to protect any exposed steel around a scratch or cut.

These coatings aren’t left up to preference. They’re governed by industry specifications. The American Galvanizers Association coating specifications cover the most common ones used in fabrication:

Specification	Covers	Typical use
A123 / A123M	Steel fabrications	Hot-dip galvanized structural and sheet steel fabrications
A153 / A153M	Fasteners and small products	Bolts, nuts, screws and similar small hardware
A767 / A767M	Reinforcing bar	Galvanized rebar for concrete
A653 G60 / G90	Continuously galvanized sheet	Coil-produced sheet and strip with G60 or G90 coating weight

The Coating is Heavier Than You Think

Not all zinc coatings are equal. Continuously galvanized sheet is relatively light, with G60 carrying roughly 0.85 mil of zinc and G90 carrying about 1.3 mil. By contrast, after-fabrication hot-dip coatings fall under specifications like A123 and are often much thicker, commonly landing in the 3 to 6 mil range depending on section size.

According to the American Galvanizers Association, spatter formation is directly proportional to coating thickness. With hot-dip galvanized steel producing more spatter than continuously galvanized sheet, even a small fillet on a thick-coated bracket can create a noticeably dirtier weld and a much heavier fume plume than the same bead on mill-finish steel.

What the Arc Does to Zinc

Zinc melts at about 787 °F and boils at about 1,665 °F. A welding arc far exceeds both temperatures. Rather than simply melting off of the joint, the coating volatilizes and the zinc vapor immediately oxidizes in the air to form zinc oxide fume. This isn’t coarse dust, it’s ultrafine particulate, predominantly under one micron. StatPearls notes that ultrafine particles smaller than one micron drive much of the pathologic effect of metal fumes.

The dose needed to cause metal fume fever isn’t enormous. StatPearls states that zinc oxide fumes of 75 to 600 mg of zinc per cubic meter over one to three hours can produce it. That makes a short, unprotected burn-in on a thick-coated part more than enough to be at risk.

Fresh Fume, Not Loose Powder

The physical state of zinc oxide makes all the difference. Aerosolized zinc oxide powder does not produce metal fume fever, whereas fresh zinc oxide fume does. Pre-existing powder is coarse enough for the lungs to handle more as nuisance dust, while freshly formed fume is fine enough to reach deep into the alveoli and trigger an inflammatory response.

This has been measured directly. Bronchoalveolar lavage of volunteers exposed to zinc oxide shows elevated interleukin-6, interleukin-8, and tumor necrosis factor, with tumor necrosis factor-alpha peaking at roughly three hours post-exposure. It’s this delayed inflammatory cascade that explains why symptoms often don’t appear the moment you lift your hood.

Ultimately, any process that puts enough heat into a zinc coating will generate more fume. Operations like air arc and carbon arc gouging to cut or strip galvanized members are especially prone to this, while processes such as stick welding can burn zinc off ahead of the weld pool, changing exposure along the way. The arc hasn’t changed, the coating simply cannot be ignored.

X-ray usually normal; may be small degree of leukocytosis; CRP elevated but nonspecific.

Then rare serious presentations, differential diagnosis, occupational history advice, quick note on red flags.

Word count target ~700-780. Let me write it out.

Symptoms, Timeline and What It Feels Like

Metal fume fever has one strange signature that trips up nearly everyone the first time they get it: the symptoms do not start while you are welding. They start hours after you stop. According to StatPearls, flu-like symptoms typically appear between 4 and 10 hours after exposure to metal-binding fumes ends, peak at roughly 18 hours, and then typically disappear within 24 to 48 hours. That lag is the reason so many workers spend a day or two convinced they picked up a bad bug at work instead of recognizing a fume exposure.

The onset window, hour by hour

Time after last exposure	What typically happens
0–4 hours	Usually nothing. You may notice a metallic taste, throat irritation or a dry cough while the fume is still fresh.
4–10 hours	The onset window. Chills, fever, headache, muscle and joint aches, nausea, malaise.
Around 18 hours	Peak. Fever at its worst, with wheezing or cough in some workers.
24–48 hours	Resolution. Symptoms fade and most people feel normal again without any specific treatment.

So if you finish a Friday shift, the fever may not show up until Saturday morning. If you pick up a Saturday overtime shift, you might wake up Sunday night shivering. The symptom list StatPearls describes is fever, myalgias, arthralgias, headache, wheezing, an intense thirst and a metallic taste in the mouth, along with cough, nausea and malaise. Two of those are diagnostic in their own right. Nobody gets a metallic taste from the flu, and nobody drinks half a gallon of water in one night unless their body is reacting to something.

The classic weekly pattern

StatPearls notes that symptoms are classically weakest on Sundays and strongest after returning to work on Mondays and Tuesdays, with improvement over the course of the work week. It sounds odd until you map it to a Monday-to-Friday schedule. You are exposed Monday through Friday, so the clock keeps restarting every Monday. By midweek the gap since your last exposure has shrunk the symptoms, and by Sunday they have faded almost completely. Then you walk back in Monday morning, inhale the fume again, and the whole sequence repeats.

Why this matters: a worker who feels completely fine on Saturday and wrecked on Monday is displaying textbook metal fume fever, not a psychosomatic complaint. OSHA’s welding fact sheet describes the same pattern. Each re-exposure restarts the timeline rather than adding to a partial recovery, so the trend can look like gradual improvement across a week and then a fresh collapse on Monday. That cycle is easy to misread as burnout, a hard training week, or just bad sleep.

What the doctor will find

Here is the part that confuses people who expect a lung disease. Pulse oximetry is generally normal, and chest X-ray, chemistry panels and coagulation parameters are usually normal as well. There may be a small degree of leukocytosis, and C-reactive protein is often elevated, but that marker is nonspecific and points to inflammation without naming the cause. In a straightforward case, the exam is largely unremarkable. OSHA’s welding hazards page makes the same point: this is a short-lived systemic reaction, not permanent lung damage.

Rare but serious presentations

StatPearls reports that severe cases may involve chemical pneumonitis, acute respiratory distress syndrome, and pneumonitis with pericarditis and aseptic meningitis. Angioedema and urticaria reactions to zinc fume exposure have also been described. These are uncommon, and they are not the typical presentation of galvanized welding sickness, but they are the reason the condition deserves respect rather than a laugh.

What else it gets mistaken for

The differential diagnosis StatPearls lists includes cadmium pneumonitis, Covid-19, influenza, Haemophilus influenzae, parainfluenza, polymer fume fever, respiratory syncytial virus, viral illness and viral pneumonia. Polymer fume fever in particular shows up around overheated plastics and some flux systems, which is worth knowing if you have ever welded aluminum with flux core and wondered why you felt rough afterward.

StatPearls stresses that the most important part of the workup is obtaining an occupational history, because failure to identify the exposure can lead to repeated unsafe exposure. Practically, that means you say the words out loud: what you welded, what the coating was, how long you were under the hood, and when you last welded. Without that, a doctor sees an adult with a fever and no cough findings and reaches for the flu.

The Numbers: Exposure Limits and How Often This Happens

Every shop owner thinks they are “under the limit.” Almost nobody can prove it without a respirator program, a ventilation survey, or an industrial hygienist. Here are the numbers for zinc oxide fume and what they do and do not tell you about risk.

OSHA and NIOSH Limits

The number most people quote comes from AWS Safety and Health Fact Sheet No. 25 on metal fume fever, which states that the OSHA standard for zinc oxide fume is 5 milligrams per cubic meter of air over an eight-hour period. That figure is not an AWS invention. It comes from OSHA’s Table Z-1 in 29 CFR 1910.1000, the air contaminants table of permissible exposure limits.

Limit	Value	Averaging period	Where it comes from
OSHA permissible exposure limit (PEL), zinc oxide fume	5 mg/m³	8-hour time-weighted average	OSHA Table Z-1, 29 CFR 1910.1000, cited in AWS Fact Sheet No. 25
NIOSH recommended exposure limit (REL), zinc oxide	5 mg/m³	10-hour shift, 40-hour week	Reported by StatPearls
NIOSH short-term exposure limit (STEL), zinc oxide	10 mg/m³	15 minutes	Reported by StatPearls
OSHA PEL for welding fumes as a composite mixture	None listed	Not applicable	NIOSH Pocket Guide to Chemical Hazards

Two numbers reading 5 mg/m³ are not the same rule. OSHA’s is a legal ceiling averaged over an eight-hour day. NIOSH’s is a recommended limit built around a ten-hour shift inside a forty-hour week, which gives a worker on long shifts more time to accumulate zinc. NIOSH also sets a short-term limit of 10 mg/m³ over fifteen minutes, and that is the number that catches someone welding one heavy coat of zinc for a quarter of an hour with the extractor off.

No PEL for “Welding Fumes”

Search OSHA’s tables for one limit covering welding fumes and you come up empty. The NIOSH Pocket Guide to Chemical Hazards lists no OSHA PEL for welding fumes as a composite mixture, and instead lists welding fumes as a potential occupational carcinogen with lung cancer as the cancer site. That absence is not an oversight: welding fume is a shifting mixture that changes with base metal, filler, flux, shielding gas and the coating being burned through. Iron fume, zinc oxide, manganese, chromium, nickel and lead have different toxicological profiles, so a single limit would be meaningless.

That is why OSHA regulates specific metals and nothing else, and why zinc gets its own paragraph. As 29 CFR 1910.252(c) puts it, indoor welding or cutting involving zinc-bearing base or filler metals, or metals coated with zinc-bearing materials, must follow the ventilation requirements of paragraph (c)(3) and confined space work under (c)(4), and employers must keep exposure below the maximum allowable concentrations in (c)(1)(iii). Read the individual metal limits and you can actually assess a job.

What Ventilation Actually Buys You

Here is the number that should end the open-doors and cross-drafts argument. NIOSH’s evaluation of two portable local exhaust ventilation units, documented in its engineering controls database, found that without LEV, total welding fume ranged from 2 to 60 mg/m³. With ventilation in place, the fume dropped to 3 to 13 mg/m³. Uncontrolled welding routinely produces concentrations well above the 5 mg/m³ limit, and even a good extractor can leave some jobs above it.

Process choice matters too. Even the process shops reach for when they want fewer variables, such as advantages of stick welding and why SMAW still wins, produces fume that must be captured. Fewer variables is not zero variables.

The Long-Term Picture

NIOSH states that welders face a 40 percent increase in relative risk of developing lung cancer as a result of their work. OSHA Fact Sheet 3647 lists health effects of certain welding fumes including metal fume fever, stomach ulcers, kidney damage and nervous system damage. StatPearls reports that roughly 30 percent of middle-aged welders had at least one episode of metal fume fever during their careers. One in three is not rare in a trade where the cause is completely predictable.

Why Your Employer May Never Have Known

The final number explains why this hazard stays invisible. StatPearls cites Louisiana Poison Control data of 26 cases over two years, in which 75 percent sought no further medical care, four were evaluated in the emergency department, and one was admitted. Most people with Monday fever shake it off and go back to work without telling anybody. So the cases your employer sees are the small fraction, and no reported cases in your shop is not evidence that your shop is safe.

Your exposure data has to come from measurement, not from the fact that nobody got sick enough to file paperwork.

The OSHA Rules That Apply to Zinc-Coated Steel

OSHA’s welding standard has a dedicated paragraph for galvanized work, and it is easy to miss. In 29 CFR 1910.252, paragraph (c) covers ventilation and protective equipment, and subparagraph (c)(6) governs zinc. Read it as a decision tree: it tells you which control strategy applies based on where the arc is.

The Zinc Paragraph: (c)(6)

Subparagraph (c)(6) splits zinc work by setting. Welding or cutting involving zinc-bearing base or filler metals, or metals coated with zinc-bearing materials, performed in a confined space must follow paragraph (c)(4), the confined space rules. The same work done indoors must follow paragraph (c)(3), the local exhaust ventilation rules.

The practical translation: indoors, an open shop door is not compliance, you need a hood or a booth. In a confined space, you need everything (c)(4) demands on top of fume capture. Because the trigger is the coated base metal, a galvanized handrail bracket cut on a shop table pulls in the indoor rule exactly like a filled tank does.

Hoods: (c)(3)(i) and the Airflow Table

Paragraph (c)(3)(i) allows freely movable hoods provided they sit as near as practicable to the work and the airflow maintains a velocity in the direction of the hood of 100 linear feet per minute in the zone of welding at the hood’s most remote distance from the point of welding. “Most remote distance” is the operative phrase: the hood must clear the plume at its furthest edge, not at the nozzle.

OSHA’s table shows how fast required airflow climbs as the hood backs away:

Distance from arc	Minimum airflow	Duct diameter
4 to 6 inches	150 cfm	3 inch
6 to 8 inches	275 cfm	3½ inch
8 to 10 inches	425 cfm	4½ inch
10 to 12 inches	600 cfm	5½ inch

That climb from 150 to 600 cfm is why a hood parked 18 inches off the bead performs so poorly. Hot zinc fume rises, and the closer the capture point, the less air the fan moves. NIOSH’s evaluation of portable local exhaust ventilation makes the same point, describing a flexible arm positioned near the welding spot with captured fume exhausted outside the welding area.

Fixed Enclosures: (c)(3)(ii)

Where a hood cannot follow the work, (c)(3)(ii) allows a fixed enclosure with a top and not less than two sides surrounding the operation, with airflow sufficient to maintain a velocity away from the welder of not less than 100 linear feet per minute. That is a booth or a screened cell with the draft pulled away from your face, not a fan pointed at the wall. OSHA’s welding hazards and solutions guidance says the same thing: capture at the source.

General Ventilation: (c)(2)

General mechanical ventilation under (c)(2)(i) is required where the space is less than 10,000 cubic feet per welder, ceiling height is under 16 feet, or confined spaces, partitions, balconies or structural barriers significantly obstruct cross ventilation. Paragraph (c)(2)(ii) sets the floor at 2,000 cfm per welder. That rate dilutes general shop air, but under (c)(6)(ii) it supplements local exhaust rather than replacing it.

Confined Space Work: (c)(4)

Paragraph (c)(4) is the hardest set of requirements in the standard. It calls for adequate ventilation with clean, respirable replacement air, and where ventilation is impossible, (c)(4)(ii) requires NIOSH-approved airline respirators or hose masks under 42 CFR part 84. Where conditions are immediately hazardous to life, workers need pressure-demand self-contained breathing apparatus or supplied-air respirators with auxiliary SCBA. An outside attendant is required, and (c)(4)(v) states oxygen shall never be used for ventilation. No exceptions.

Exposure Limits, HazCom and First Aid

Three more duties ride along. Paragraph (c)(1)(iii) requires exposures below the maximum allowable concentrations in 29 CFR 1910.1000, Table Z-1, home of the 5 mg/m³ permissible exposure limit for zinc oxide fume. Paragraph (c)(1)(iv) requires hazard communication for coatings, fluxes and filler metals, so zinc-rich primers, flux-cored wire and E-series electrodes belong in the HazCom program with labels and safety data sheets. Paragraph (c)(13) requires first-aid equipment on hand at all times, injuries reported as soon as possible for medical attention, and first aid rendered until medical attention arrives.

That last point bites harder than it sounds. A welder who develops metal fume fever on Sunday night and says nothing about Monday’s shift still had an unreported injury, so the exposure behind it never gets fixed. Respiratory protection under 29 CFR 1910.134 closes the loop when engineering controls fall short.

Compliance gets simpler once the coating comes off before the arc does. The next two sections cover removing the zinc entirely, then running ventilation and respirators properly when you cannot.

Prevention Option One: Get the Zinc Off the Steel First

If you only remember one control for galvanized welding sickness, remember this: the safest weld on galvanized steel is the one made on bare metal. Removing the coating before you strike an arc eliminates the source of the fume rather than trying to capture or respirate it. The American Galvanizers Association (AGA) leans on that approach in its guidance for hot-dip galvanized steel.

The AGA cites AWS D-19.0, Welding Zinc Coated Steel, which calls for welds of galvanized steel to be made on areas free of zinc. For galvanized structural fabrications, the AGA states the coating should be removed at least 1 to 4 inches (2.5 to 10 cm) from either side of the intended weld zone, on both sides of the piece, not just around the puddle.

Arc heat spreads. A hot, fast fillet weld bead can cook zinc from several inches away, drawing it into the weld zone as the coating volatilizes ahead of the pool. Strip 1 to 4 inches wide and the zinc is gone when the arc arrives.

Grinding Versus Fume: What Actually Changes

Grinding is preferred for a reason: it creates dust, not fume. According to StatPearls on metal fume fever, aerosolized zinc oxide powder does not produce the syndrome the way fresh fume does. Fresh fume is ultrafine, sub-micron zinc oxide that reaches deep into the lung and drives the inflammatory response, while pre-existing zinc oxide powder is coarse, relatively inert, and filtered out before it does the same damage.

So the honest framing: grinding moves you out of the zinc fume hazard and into the zinc dust hazard, an easier problem to solve but not a zero one. Airborne zinc dust still irritates the airways, still warrants respiratory protection, and still needs housekeeping.

Use a grinder with a shroud and handle, work outdoors or under local exhaust, wear a respirator, and keep dust off horizontal surfaces where it can be kicked back into the breathing zone. A shop that grinds stainless or solid aluminum already has the hardware and the habit.

Special Cases You Will Run Into

The AGA spells out the exceptions:

Stud welding. If you weld galvanized studs onto galvanized steel, the coating must come off the stud end and the base surface. If zinc volatilizes from the faying surface, the expanding gas can expel weld metal from the joint. That is a spray hazard and a failed connection, not a cosmetic defect.

Rebar. The AGA states rebar can be welded by SMAW or GMAW without removing the zinc coating, though removing zinc within 2 inches (50 mm) of the weld joint is preferred. Coating condition is another variable alongside all-position electrode selection for rebar work.

Friction welding of studs. Flat-ended studs cannot be friction welded to galvanized plate, because the zinc coating’s alloy layers act as a low-friction bearing surface and the stud just spins. Pointed studs with a 120-degree point solve it.

Or Skip the Problem Entirely: Weld Before You Galvanize

The AGA states welding before and after galvanizing are both compatible with providing superior corrosion protection. If you have design freedom, welding first and sending the structure to the galvanizing kettle removes the fume hazard from the shop entirely. There is no coating to strip because there is no coating yet.

What that costs is the ability to field-modify the structure afterward. The AGA advises minimizing field fabrication that requires coating removal, because cathodic protection will provide some protection to uncoated areas. Bare steel left after a field weld is not left naked; the surrounding zinc sacrifices itself to protect it.

Comparing Removal Methods

Method	Concern	Labor	Coating	Steel contamination
Angle grinder (preferred)	Zinc dust, not fume. Needs LEV and respirator.	Moderate	None beyond strip width	Minor
Abrasive blasting	Dust plus embedded abrasive, heavy cleanup	Low to moderate	Can erode coating edges	Risk with shared abrasive
Wire brush plus torch heat	Produces fume, worst option	Low	Distorts coating locally	Minimal
Chemical de-zinc or pickling	Acid mist and zinc salts	Low, slow setup	Full removal to bare steel	Residue must be neutralized

Grinding wins on the criteria that matter: it is fast, it removes exactly what you want removed, and it does not put zinc into the air as fume. Keep dedicated tools separate from aluminum and stainless work, following good aluminum cleaning for welding practice. Strip the coating and the hazard stops being an air problem; it becomes a preparation problem, much easier to solve, inspect and document.

Prevention Option Two: Ventilation and Respiratory Protection Done Right

Grinding the coating back is the cleanest fix, but plenty of jobs do not allow it: a repair weld on a galvanized handrail in a hospital basement, a duct spool in a mechanical room, a truss member spliced on a bridge job. When the zinc stays, your plan has two layers. Capture the fume at the source, then protect the welder where capture is imperfect.

Local exhaust ventilation comes first

OSHA’s control hierarchy puts engineering measures ahead of respirators, and for zinc that means local exhaust ventilation, not open windows and a box fan. The NIOSH engineering controls entry describes two portable LEV units that were evaluated, including a mobile wheeled unit with a 2-meter flexible arm. Workers place the unit near the welding spot to capture fumes at the point of generation, and the captured air is exhausted through flex-duct to a point outside the welding area.

Without LEV, total welding fume concentrations ranged from 2 to 60 mg/m³. With ventilation they dropped to 3 to 13 mg/m³. That is why one fume extractor can change every galvanized job a shop runs. If you are spec’ing blowers, ducts or hoods, the Airgas welding equipment guide helps you sort out what you actually need.

Where you put the hood matters more than what you buy

Fume rises, and it also spreads outward and forward from the arc. A hood behind the welder or level with the arc catches a fraction of what a hood placed above and to the side of the arc captures, and no fan rating fixes a positioning problem.

Distance changes the required airflow just as much. OSHA 1910.252(c)(3)(i) requires airflow sufficient to maintain a 100 linear feet per minute control velocity in the welding zone at the hood’s most remote point, and its table spells out the demand:

Distance from arc	Minimum duct airflow	Duct diameter
4 to 6 inches	150 cfm	3 inches
6 to 8 inches	275 cfm	3½ inches
8 to 10 inches	425 cfm	4½ inches
10 to 12 inches	600 cfm	5½ inches

Read that table as a placement instruction. Stay close to the arc and the same unit does the job.

General ventilation is not a substitute

General dilution has a place. 1910.252(c)(2) calls for at least 2,000 cfm per welder when the space is small, ceilings are under 16 feet, or partitions and structural barriers block cross ventilation. But OSHA’s zinc paragraph points indoor zinc work to the local exhaust requirements in (c)(3), so a big fan stirring the shop is not compliance.

Choosing a respirator honestly

There is a catch before you pick a filter class. The NIOSH Pocket Guide to Chemical Hazards lists no OSHA PEL for welding fumes as a composite mixture, because welding fume is a changing mix depending on base metal, filler and shielding gas. Recommended protection is a pressure-demand full-facepiece SCBA or a supplied-air respirator with an auxiliary self-contained positive-pressure apparatus, used above the REL or at any detectable concentration where no REL exists. For escape from an emergency, NIOSH lists an air-purifying full-facepiece respirator with an N100, R100 or P100 filter.

Under 1910.134(d)(3)(iv)(B), protection against particulates calls for a NIOSH-certified HEPA filter (N100, R100, P100) or a 42 CFR 84 certified filter, while (d)(3)(iv)(C) allows any NIOSH-certified particulate filter for contaminants consisting primarily of particles with mass median aerodynamic diameters of at least 2 micrometers. StatPearls adds a blunt reality: while N95 masks have become standard protection for welders, they are not as effective as elastomeric half-face masks, full-face respirators and powered air-purifying respirators. A disposable dust mask is a comfort item, not a zinc control.

The program behind the respirator

1910.134(a)(1) is explicit that the primary objective is preventing atmospheric contamination through accepted engineering control measures, with respirators used when those controls are not feasible or while they are being instituted. 1910.134(f)(2) requires fit testing before initial use of a tight-fitting respirator, whenever a different facepiece is used, and at least annually thereafter. Subsection (g)(1) prohibits wearing a tight-fitting facepiece with facial hair that interferes with the seal and requires a user seal check each time the respirator is put on. A written program, medical evaluation, training and maintenance are what make the respirator work.

Common Mistakes That Trigger Galvanized Welding Sickness

With all of the information about zinc fume hazards out there, it’s still the smallest oversights that land welders with a case of galvanized welding sickness. Most of these mistakes aren’t born out of negligence, they’re born out of habit. With a quick audit, though, every one of them is fixable.

Ventilation Mistakes

• Relying on an open shop door: Cracking a bay door or propping open a roll-up is not ventilation. For indoor work with zinc-coated steel, 29 CFR 1910.252(c)(6) routes the work to paragraph (c)(3), requiring local exhaust hoods or booths rather than general dilution alone. Cross-drafts can shift the fume plume right into your breathing zone.
• Placing your fume extractor in the wrong spot: Hot zinc oxide fume rises, so it won’t be captured if your hood is behind, far away, or off to the side of the arc. OSHA’s hood airflow table makes this painfully clear: you’ll need roughly 150 cfm at 4-6 inches from the arc, but that jumps all the way up to 600 cfm at 10-12 inches. The closer you can get your capture point to the source, the safer and more efficient you’ll be.
• Pinching or coiling your LEV hose: A portable extractor with a kinked, coiled, or stretched-out hose can choke its airflow without any warning lights going off. Always keep your flex hose as straight and short as possible to maintain the control velocity your job requires.
• Welding in tight, unventilated spaces: Tanks, silos, ducting, columns, or any other confined space can become a fume trap within minutes. These jobs fall under 29 CFR 1910.252(c)(4) and require additional precautions, including an outside attendant and, in many cases, supplied-air or NIOSH-approved breathing equipment. Most importantly, oxygen shall never be used for ventilation in a confined space.

Respiratory and Preparation Mistakes

• Grabbing a dust mask: A standard nuisance dust mask simply isn’t cut out for zinc fume. As noted by StatPearls, N95 masks are less effective than elastomeric half-face respirators, full-face respirators, or PAPRs. Selection must be made with the correct assigned protection factor in mind, and in accordance with OSHA 1910.134.
• Thinking grinding solves the fume problem: Removing the zinc coating by grinding is one of the most effective preventative measures, however it comes with a trade off. StatPearls states that aerosolized zinc oxide powder does not produce the symptoms of metal fume fever the same way fresh zinc oxide fume does due to particle size. That doesn’t mean it’s harmless. Grinding creates respirable zinc dust, meaning respiratory protection and proper housekeeping are still required.
• Breaking your respirator seal: Welding with your helmet down over a loose-fitting respirator is a recipe for exposure. Facial hair, a rushed strap adjustment, fogged lenses, or constantly lifting your helmet to see your work can all allow the plume to bypass your respirator entirely. User seal checks should be performed every time it’s donned.

Awareness and Response Mistakes

• Ignoring the “Monday Fever” pattern: One of the biggest red flags is timing. StatPearls notes the most characteristic pattern of metal fume fever is symptoms appearing on Monday and Tuesday and being absent on Sundays. If you feel wrecked after returning from a weekend off, but better throughout the work week, do not write it off as coincidence. Re-exposure brings those symptoms right back.
• Assuming it’s just the flu: Fever, chills, body aches, a metallic taste, and fatigue are all classic. However, the most common reason for a missed diagnosis, according to StatPearls, is a failure to take an occupational and hobby history. If you visit a clinician, be specific: tell them the material you were welding, the duration, if it was galvanized, and the timeframe of your symptoms. This one conversation can prevent a cycle of repeated, unsafe exposures.
• Pushing through early symptoms: Rest is not giving up. These symptoms typically onset anywhere from 4-10 hours after exposure and peak around 18 hours. Continuing to weld while symptomatic only increases your total fume dose and greatly increases the chance of repeating this cycle week after week.

The truth is simple: control the source. Whether that’s removing the zinc coating before you strike an

Welding Galvanized Steel Without Ruining the Weld

Welding galvanized steel isn’t just about getting a solid joint, it’s about striking a balance between safety, metallurgy, and preserving the corrosion protection that drew you to the material in the first place. According to the American Galvanizers Association (AGA), both welding before and after hot-dip galvanizing are compatible with superior long-term protection, but if you’re working after galvanizing, the key is knowing how to account for the zinc coating without leaving gas pockets, excessive spatter, or bare steel exposed.

GMAW (MIG) Considerations

When running Gas Metal Arc Welding on galvanized steel, the coating fundamentally changes the behavior of the weld pool. The AGA notes that welding speeds on galvanized surfaces are typically slower to allow the zinc to burn off at the front of the weld pool, and increasing current may burn off thicker coatings. However, penetration depth is decreased compared to uncoated steel, so larger butt joint gaps must be provided. For consistent penetration on flat butt joints, a side-to-side torch motion is required.

Spatter is also one of the biggest headaches for this process. With CO2 shielding gas, spatter increases and is directly proportional to coating thickness. To combat this, the AGA recommends applying a silicone-, petroleum-, or graphite-based spatter release compound before welding. For the cleanest results, increasing heat, reducing travel speed, and using an argon-CO2 shielding gas mix will produce a more stable arc, smoother deposits, minimum spatter, and less zinc loss.

SMAW (Stick) Considerations

For Shielded Metal Arc Welding, a slight change in technique goes a long way. The AGA states that the electrode angle can be reduced from the normal 70 degrees down to 30 degrees, paired with a reduced travel speed to achieve normal weld depths. Most importantly, use a whipping action to allow the zinc to burn off before the weld bead advances. Avoid weaving and multiple weld beads whenever possible, keep heat input to a minimum, and use a short arc. For steels thicker than 1/2 inch (13 mm), SMAW is the recommended process for galvanized steel.

Oxyacetylene Welding Considerations

While less common for structural galvanized work, oxyacetylene welding requires a delicate hand. Use a ripple weld with the filler rod moved back and forth to allow the zinc to volatilize as you go. Most critically, welds should not be remelted by a flame to improve their appearance, as this will result in additional loss of the zinc coating with no benefit to the joint.

Restoring the Zinc Coating After Welding

No matter how careful your technique is, some coating will be lost around the weld. For repairs, ASTM A780 provides three approved touch-up methods:

• Zinc-based solder: Preheat the area to approximately 600 °F (315 °C) before application.
• Zinc-rich paint: Must contain either 65% to 69% metallic zinc by weight or greater than 92% metallic zinc by weight in the dry film. Apply at 50% more thickness than the surrounding coating, but not greater than 4.0 mils (100 µm).
• Zinc spray metallizing: Utilize zinc that is nominally 99.5% pure or better.

For all of these methods, touch-up materials are required to meet a coating thickness of at least 2.0 mils (50.8 µm) for a single application. For newly galvanized material, ASTM A123 only allows minor repairs if a bare spot is one inch or less in its narrowest dimension, and the total area is no more than 1/2 of 1% of the accessible area, or 36 square inches per short ton per piece, whichever is less. Anything beyond these limits requires a full recoating evaluation, not a rushed dab of paint. With the right process, proper cleanup, and code-approved touch-up, you can keep your joint strong without sacrificing the protection the galvanizing was there to provide.

After an Exposure: What To Do, What To Report, and How to Stop It Happening

Most metal fume fever cases resolve on their own within 24 to 48 hours. It is miserable, and for the typical welder it is not an emergency, but the decisions made in the hours after exposure and the days after that are what separate a one-off episode from a repeated one.

What the Affected Weld Should Do Right Now

Step away from the arc. Get outdoors or into good ventilation, loosen your gear, rest, drink fluids, and take a simple antipyretic such as ibuprofen or acetaminophen if you have no contraindication. That matches the approach in StatPearls: mostly mild and self-limited, symptom-based treatment with antipyretics for fever and fluids for dehydration, occasionally oxygen for hypoxemia, and inhaled beta-agonists and glucocorticoids when bronchospasm is prominent.

The most important step is medical. When you call the doctor or walk into urgent care, say the words: I welded galvanized steel yesterday and now I have flu-like symptoms. Cases get missed because nobody connects the illness to the shift. If the clinician wants more, bring the specifics: what you welded, how long, whether the coating was ground back, whether a fume extractor was running, how hot it felt, and your hours on the job.

What the Employer Has to Do

29 CFR 1910.252(c)(13) is short and unambiguous. First-aid equipment must be available at all times, all injuries must be reported as soon as possible for medical attention, and first aid must be rendered until medical attention can be provided. An exposure that sent a welder home shaking is not a private matter to handle informally.

Beyond first aid, two other programs apply.

• Respiratory protection under 1910.134. 29 CFR 1910.134(c)(1) requires a written, worksite-specific program covering respirator selection, medical evaluations, fit testing, proper use, maintenance, training on the hazard and the respirator, and regular evaluation of program effectiveness. 1910.134(c)(4) requires that respirators, training, and medical evaluations be provided at no cost to the employee.
• Hazard communication under 1910.252(c)(1)(iv). The employer must include potentially hazardous materials in fluxes, coatings, coverings, and filler metals in the HazCom program, with employee access to labels and safety data sheets plus training on those hazards. Zinc coating dummies, zinc-bearing fluxes, and the SDS for your wire and consumables belong in that program, not in a drawer.

StatPearls also points to workplace assessment by occupational health personnel or industrial hygienists, keeping your head and face away from the fumes, increasing ventilation in the work zone with sufficient exhaust provided, and keeping safety education in place wherever welding happens. NIOSH’s engineering controls entry adds the research basis, noting that animal and epidemiological studies link welding with metal fume fever, pneumonitis, chronic bronchitis, and decrements in pulmonary function.

Getting a Second Set of Eyes on the Job

You do not have to guess whether your booth actually captures. In the United States you can request a Health Hazard Evaluation involving NIOSH, including a workplace visit, and the process can be initiated by an alert clinician, nurse, or pharmacist as well as by the employer. A welder with symptoms plus a doctor who suspects an occupational cause can trigger a professional evaluation of the welding area, which beats everyone quietly blaming the weather.

The Pre-Job Checklist

Run this before the arc strikes, every time:

1. Identify the coating and its thickness. Hot-dip or sheet, and how thick?
2. Can the zinc be ground back 1 to 4 inches from the weld zone on both sides?
3. Is the work outdoors, indoors, or inside a tank, silo, duct, or column?
4. Is local exhaust positioned within 6 to 12 inches of the arc, above and beside it?
5. Which respirator is specified, and is that wearer’s fit test current?
6. For confined space work: is there an outside attendant, and is the correct respirator in place?
7. What is the touch-up plan for the bare steel, and who applies it?

Full-size fume extraction, a clean respirator fit, and a fresh coating repair keep you on the productive side of the exposure limit. If you are still weighing extraction equipment, our guide to AllGas welding supply and safety covers the gear side of the shop setup.

The Bottom Line

Galvanized welding sickness is preventable, and for most workers it is a one-to-two-day inconvenience once it happens. The catch is that the exposure behind it is cumulative, and the symptoms are the receipt, not the source. Control the source rather than enduring the symptom: get the coating off where you can, ventilate where you cannot, protect the welder where you must, and document everything in between.

Frequently Asked Questions

What is galvanized welding sickness?

It is the trade name for metal fume fever (also called zinc fever or welders’ ague) caused by breathing zinc oxide fume while welding zinc-coated steel. OSHA notes that zinc exposure is the usual cause of metal fume fever, and that symptoms typically include fever, nausea and coughing. It is an inhalation injury, not a skin or weld-quality problem.

How soon after welding galvanized steel do symptoms appear?

Usually 4 to 10 hours after you stop welding, peaking around 18 hours and resolving within 24 to 48 hours. Because of the delayed onset, people often blame the flu, the weather or bad food. If symptoms start right after a shift, think about whether the exposure was heavy.

Is it dangerous to weld galvanized steel without a respirator?

It depends on the conditions, but OSHA treats zinc as a regulated hazard with its own ventilation requirements. Indoors, 29 CFR 1910.252(c)(6)(ii) requires local exhaust ventilation under paragraph (c)(3); in confined spaces, paragraph (c)(4) rules apply, including NIOSH-approved airline respirators where ventilation is impossible. A respirator alone is not a substitute for engineering controls under 1910.134(a)(1).

What is the OSHA exposure limit for zinc oxide fume?

The OSHA permissible exposure limit for zinc oxide fume is 5 mg/m3 as an eight-hour time-weighted average, as cited in AWS Safety and Health Fact Sheet No. 25. NIOSH recommends the same 5 mg/m3 averaged over a ten-hour shift and forty-hour week, with a short-term limit of 10 mg/m3 over fifteen minutes.

Do I have to remove the zinc coating before welding?

AWS D-19.0, as summarized by the American Galvanizers Association, calls for welds on areas free of zinc, and the AGA recommends removing the coating at least 1 to 4 inches (2.5 to 10 cm) from either side of the weld zone on both sides of the piece. Galvanized steel can also be welded with the coating left in place if special procedures are followed and the work is well ventilated.

Is a dust mask (N95) good enough for welding galvanized steel?

It is the weakest option. StatPearls notes that while N95 masks have become standard for welders, they are not as effective as elastomeric half-face masks, full-face respirators or powered air-purifying respirators. For particulate fume, OSHA generally calls for a NIOSH-certified HEPA filter (N100, R100 or P100) with a full facepiece, and respirators require fit testing, medical evaluation and a written program.

Can I weld galvanized steel indoors at all?

Yes, but not with the door open and a prayer. OSHA routes indoor welding of zinc-bearing materials to local exhaust ventilation under 1910.252(c)(3): freely movable hoods placed as near as practicable to the work with 100 linear feet per minute control velocity, or a fixed enclosure with a top and at least two sides. General ventilation alone does not satisfy the zinc paragraph.

How do I tell metal fume fever apart from the flu or COVID?

The pattern is the giveaway: symptoms that clear over the weekend and return every Monday and Tuesday are classic metal fume fever, and pulse oximetry and chest X-ray are usually normal. StatPearls lists COVID-19, influenza, parainfluenza and viral pneumonia among the differential, which is exactly why you must tell the clinician that you weld galvanized steel.

What should I do if I feel sick after a shift welding galvanized steel?

Get out into fresh air, rest, drink fluids and treat the fever with a simple antipyretic. Then tell your supervisor and a doctor about the exposure and your shift details so an occupational history can be taken, and seek care promptly if you have chest pain, trouble breathing at rest, confusion, or symptoms lasting more than about 48 hours.

Does grinding the zinc off completely solve the problem?

It removes the source of the fume, which is the strongest control, but grinding produces zinc dust rather than fume. StatPearls notes aerosolized zinc oxide powder does not produce metal fume fever the way fresh fume does because of particle size differences, yet dust still needs respiratory protection and cleanup. And every bit of coating removed is coating you have to restore afterward per ASTM A780.