Ammonia is gaseous under normal conditions, meaning that any leak would result in presence of gaseous ammonia in air. 500 mg of ammonia per m3 of air can damage

Ammonia is gaseous under normal conditions, meaning that any leak would result in presence of gaseous ammonia in air. 500 mg of ammonia per m3 of air can damages eyes, a short exposure to 3g can have overall toxic effects, at 7 g and higher it damages the skin. Gasoline, hydrogen, or monoxide don't come close to this level of toxicity.