Bleach Stones converts slowly into Chlorine and are thus used to fight germs directly or by creating Hand Sanitizer. They can be found in certain biomes or spawn around chambers with Chlorine.

To store them safely and prevent them from converting into Chlorine they can be placed into a room with maximum gas pressure from another gas, for example carbon dioxide. They emit Chlorine even if placed into storage locker - which can be used to sanitize contaminated food or materials.