CAW National Council 4000
Occupational Health and Safety

Hazardous Substances:  Manganese

Manganese can create ill-health effects when inhaled or swallowed.

Short-Term Effects

Inhalation of fumes with high concentrations of manganese and its oxides may bring about "metal fume fever". Symptoms of metal
fume fever are chills and fever, upset stomach, vomiting, dryness of the throat, cough, weakness, and aching of the head and body.
Symptoms often occur several hours after exposure to fumes and usually last for only a day.

Many manganese salts have caustic properties.

Long-Term Effects

Prolonged or repeated exposure to manganese may affect the nervous system with difficulty in walking and balancing, weakness or
cramps in the legs, hoarseness of the voice, trouble with memory and judgment, unstable emotions or unusual irritability. If high
exposure continues, a person may have poor coordination, difficulty in speaking clearly, or shaking or tremor of the arms or legs. A
person may also have hallucinations or uncontrollable laughter or crying.

At this stage the condition becomes irreversible. There is evidence to show that the condition continues to worsen even if there is
no further exposure to manganese.

The respiratory system may be affected by a condition known as "manganese pneumonia", which may result in symptoms and signs
of coughing, fever, chills, general aching of the body, chest pain, and other common signs of pneumonia. A manganese
pneumoconiosis may result.


Enclose process
Local exhaust ventilation
General dilution ventilation
Person protective equipment


ACGIH TLV dust 0.2 mg/m3 (as manganese)

Source:  CAW Health, Safety & Environment Department