Celebium shielding

From Memory Alpha, the free Star Trek reference.

Celebium shielding is a material used in the construction of Federation outposts, protecting humanoid life from exposure to toxic celebium. In 2269, Drs. Janice Lester and Arthur Coleman murdered the entire population of a Federation research outpost on planet Camus II by ordering them into an area where they knew the celebium shielding was weak. (TOS: "Turnabout Intruder")