The vapour is heavier than air. Reacts slowly with water and water vapour, forming hydrogen bromide and hydrogen cyanide. The substance is corrosive to the eyes, the skin and the respiratory tract. Exposure may result in death. The effects may be delayed.
Medical observation is indicated.
TLV not established. Repeated or prolonged exposure may cause enlargement of the thyroid gland. The symptoms of lung oedema often do not become manifest until a few hours have passed and they are aggravated by physical effort.