Ammonia

Ammonia was a gas compound made up of nitrogen and hydrogen. A constituent of the atmosphere of many gas giants, it was caustic and slightly toxic to most species. One type of ammonia was Vanoorian ammonia, which was found on Vanooria. The planet Gand, homeworld of the species of the same name, had an atmosphere composed primarily of ammonia rather than oxygen, causing it to be poisonous to most off-worlders.