Bakelite

Bakelite (ベークライト) is a fast-setting red-colored phenol resin, which, after being released in liquid state, quickly hardens in a similar fashion to that of quick drying concrete. Bakelite is deployed inside of NERV HQ in the event that an Evangelion breaks loose and needs to be quickly restrained. Also, part of NERV HQ's defensive system is to flood presumably most or possibly all access corridors with bakelite, as means of cutting off the advance of an approaching enemy. It is used to block entire passage ways in an effort to stop the Japanese Strategic Self Defense Force troop movements inside NERV Headquarters as can be seen in The End of Evangelion.

After Adam was reduced to an embryonic state, the embryo was encased in bakelite in order to freeze it and make it easy and safe to transport.