|The following is based on Fallout Tactics and is not canon.|
Environmental armor is a piece of armor in Fallout Tactics. It was developed for use in heavily contaminated environments, and is prized in the Wasteland for its ability to protect against biological threats.
Knights of the Brotherhood of Steel are sometimes dressed in environmental armor. This protects them against radiation, chemical and bio warfare agents. Of course, it also helps with the brahmin smell. Unlike leather and metal armors, which cannot be used by ghouls, both variations of environmental armor are suitable for ghouls.
Environmental armor appears in Fallout Tactics.
Early concept art