Tuesday 22 December 2015, a tank truck carrying carbon dioxide downtown Mainz in Germany, presented a leak and it covered the streets with a thick cloud of white smoke.

The damage caused by a defective safety valve. The truck driver tried to contain the leak without success injuring his hand, after the stored gas temperature in the truck reached -60 ° C. Twenty policemen and about 80 firefighters intervened asking residents to close their doors and windows.

At a certain concentration in the air, carbon dioxide is dangerous, even fatal. The exposure limit for humans is 3% within 15 minutes. 10%, can create visual disturbances, chills and sweating. In 15% causing unconsciousness, while 25% stoppage of breathing killing.