Bakelite

Bakelite is a fast-setting phenol resin, which after being released in liquid form will quickly harden. Similar to very quickly drying, extremely hard concrete (but made of essentially plastics), bakelite is deployed inside of Nerv HQ in the event that an Evangelion loses control and needs to be quickly restrained. Also, part of Nerv HQ's defensive system includes the capacity to flood presumably most or possibly all access corridors with bakelite, as a means of cutting off enemy approach.

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

Notes

• Bakelite is actually a real-life substance, however, real bakelite doesn't have the properties that "bakelite" does in the series. Real bakelite is "cured" from its liquid precursor under heat and pressure, and in its pure form is very brittle. Bakelite in the series is poured and sets at room temperature, and has a tensile strength great enough to hold an Evangelion in place when it has dried.