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Who is at risk?

Power stations – radioactive isotopes of iodine - people who work at facilities using radioactive iodine may be exposed to higher than normal levels.

Iodine-131 is the radioactive gas that was released during the 1986 Chernobyl nuclear accident.


Irritating odour


At room temperature, Iodine crystals will volatize into a violet-blue gas. In this gaseous state, Iodine is extremely poisonous and severely irritates the lungs, eyes and bronchial tubes.

Acute Exposure

Concentration Effect
1.5 - 2 ppm Eye, skin and throat irritation
3 - 5 ppm Tearing of the eyes
10 - 20 ppm Burning of nose and throat, difficulty in breathing and heavy tearing of the eyes
25 - 50 ppm Chest tightening, irregular heartbeat, severe lung irritation, pulmonary edema
100 ppm Immediately dangerous to life and health, death.

Exposure Controls & Protection

Leak Detection & Monitoring

Iodine is difficult to detect with real-time monitoring instruments. Evidence sampling should be done in well-ventilated areas using appropriate respiratory protection.

NFPA 704 Signal

  Hazard Value Description
Health 3 Can cause serious or permanent injury.
Flammability 0 Will not burn under typical fire conditions.
Instability 0 Normally stable, even under fire conditions
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