Death mist

The death mist, also known as red mist, was a biological weapon created by the Charon species. In small quantities, it was capable of inflicting intense pain, as well as hallucinatory images and madness to an organic target, as it affected the nervous system of the being it came into contact with. This allowed the Charon to incapacitate those beings they wished, however, in larger quantities it was easily capable of killing its victim as they suffered a complete and total failure of their nervous system. The only viable defense against the death mist was to wear sealed vacuum suits as the mist would cling to skin and enter the body through pores making it very difficult to escape once it touched its victim.

Text and facts from the “Death mist” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.