It is also chosen for soluble (but not volatile) chemicals, since the evolution of carbon dioxide is considered by many to be the only unequivocal proof of microbial activity.
Seda on samuti kasutatud lahustuvate (kuid mitte lenduvate) kemikaalide puhul, kuna süsinikdioksiidi teket peavad paljud ainsaks kindlaks tõendiks mikroobide tegevuse kohta.