| − | Butylene (C<sub>4</sub>H<sub>8</sub>) is an [[olefinic]] [[hydrocarbon]] recovered from refinery processes. | + | Butylene (C<sub>4</sub>H<sub>8</sub>) is an [[olefinic]] [[hydrocarbon]] recovered from refinery processes. Butylene is highly toxic to humans and can only be handled while wearing a Level-3 or above [[gas mask]]. Butylene reacts with the olfactory sensors in the base of the nose, blocking [[oxygen]] intake. |