The Definition of Metal Fume Fever

Definition of Metal Fume Fever

Metal fume fever is a short-term illness caused by breathing in fine particles of metal oxide fumes, most often zinc oxide. It produces flu-like symptoms that usually start a few hours after exposure and clear up within one to two days. It is also known as welder's flu, zinc shakes, brass founder's ague or Monday morning fever, because symptoms are often worse after a break from exposure, such as at the start of the work week.

The illness is most common among welders, cutters and grinders working on galvanized (zinc-coated) steel, and among workers in brass foundries, zinc smelting and metal spraying. Fumes from heating copper, magnesium and some other metals can also cause it.

Metal fume fever itself is usually temporary, but it is a warning sign that a worker is breathing in too much metal fume. The same exposures can include more dangerous metals such as cadmium, lead, manganese or hexavalent chromium, which can cause serious, long-term harm.

Symptoms of Metal Fume Fever

• Metallic or sweet taste in the mouth.
• Dry throat, cough and chest tightness.
• Fever and chills.
• Headache, fatigue and muscle or joint aches.
• Nausea and sweating.

Symptoms typically appear 3 to 10 hours after exposure and resolve within 24 to 48 hours. Workers can develop a short-term tolerance with repeated exposure, which is lost after a few days away from work. Anyone with severe breathing difficulty, high fever or symptoms lasting more than two days should get medical care, since other conditions, including more serious chemical exposures or infections, can look similar.

Preventing Metal Fume Fever

Engineering controls

• Use local exhaust ventilation, such as fume extraction arms or fume-extracting welding guns, to capture fumes at the source.
• Improve general ventilation in welding shops and enclosed spaces.
• Remove zinc coatings from the weld area before welding, where possible, using grinding with dust control.

Work practices

• Position the head out of the fume plume and work upwind where possible.
• Avoid welding galvanized material in confined spaces without adequate ventilation. See confined space.
• Include fume hazards in hot work planning and job briefings.

Personal protective equipment

Where engineering controls do not keep exposures low enough, provide respiratory protection, such as a particulate respirator rated for metal fumes or a powered air-purifying respirator, with proper fit testing.

Monitoring

Air monitoring can measure workers' exposure to zinc oxide and other metals and confirm whether controls are working. OSHA's permissible exposure limit for zinc oxide fume is 5 mg/m³ as an 8-hour time-weighted average.

Example of Metal Fume Fever

A fabrication shop took on a rush job welding galvanized steel brackets. Over two days, several welders reported a metallic taste, chills and body aches in the evenings. One welder took a sick day with fever.

The supervisor recognized the signs of metal fume fever. An industrial hygienist found that portable fume extractors were not being positioned close to the work and that the shop's roll-up doors had been kept closed due to cold weather. The shop added fume-extracting welding guns, retrained welders on positioning extraction arms, provided powered air-purifying respirators for galvanized work and arranged for zinc coating to be ground off weld areas with dust collection. No further cases were reported.

Frequently Asked Questions: Metal Fume Fever

Is metal fume fever dangerous?

The illness itself is usually short-lived, but it shows that a worker is overexposed to metal fumes, which can include more harmful metals. Exposure should always be reduced.

Does drinking milk prevent metal fume fever?

No. There is no scientific evidence that milk prevents or treats metal fume fever. The only reliable prevention is reducing exposure.

Is metal fume fever reportable?

If it is work-related and meets OSHA recording criteria, such as medical treatment beyond first aid or days away from work, it must be recorded.