OI-234935 Hatch eats bottled polluted water

I'm not sure if this is really a bug as such? They did in Beta, didn't in Thermal, and then did again in Outbreak and Oil. Frankly, I've been exploiting this to keep my latrines clean in Outbreak. They will also eat bottled clean water and polluted dirt, but I haven't seen them eat bottled gas.

Do they then produce coal? Cause i think hatches dont produce coal when eating food, which potentially is a bug i guess?