
Raj, why don't you go get the CHARCOAL?
The Big Bang Theory Season 2, Episode 18

Fine, it has
a CHARCOAL filter in it.
The Big Bang Theory Season 11, Episode 12

in the form of
CHARCOAL briquettes
The Big Bang Theory Season 5, Episode 12

Hey, we could liberate some
microporous CHARCOAL from the chem lab.
The Big Bang Theory Season 2, Episode 18