"A plastic card engraved with an ID is attached to it. It seems to be coated with some kind of special painting."
— Item examination - English
"ＩＤの刻まれたプラスチックのカードがついている 特殊な塗料が塗ってあるようだ "
— Item examination - Japanese
The Facility Key is a key item featured in Resident Evil 3: Nemesis. In the Japanese version, it is referred to as the "Treatment Plant Key" (処理施設のカギ Shori shisetsu no kagi ).
This key can open the door in the facility entrance that leads to the Treatment control room. Closed door reads "TREATMENT CONTROL ROOM. It's closed." This door will be closed only in that case, if Jill has pushed Nemesis off the bridge during their last encounter. In other ways, the door can just be unlocked from the other side.
Also, this key can be used for opening the weapon locker in the basement. But before, the plastic card attached to the key must be processed by the ultraviolet machine in the Water quality examination room.
When changed, the plastic card has another painting. Also, after checking a new message can be read "The plastic card is radiating. It seems to show some kind of code pattern.".
Ultraviolet machine reads the message initially: "Ultraviolet rays are applied to the water. There's a tiny slot where a plastic card could fit.".
And the weapon locker reads next message: "It is closed with a sturdy-looking door. There's a tiny slot where a plastic card could fit.".
After opening the weapon box, this item disappears without warning.
- BIOHAZARD 3 LAST ESCAPE OFFICIAL GUIDEBOOK. Famitsu. 1999.