It is Potassium sorbate; one of the most used preservatives for food, wine, and dietary supplements. Potassium sorbate is safe and effective to protect food, wine, and dietary supplements from a wide variety of microorganisms, yeast, and mold.
It is required by the FDA that the efficacy of the preservative to protect the liquid dietary formulation is tested, proven, and documented. The specific test used is the USP <51> (Antimicrobial Effectiveness Test). ClearDrops® preserved with Potassium sorbate passes the FDA-required Antimicrobial Effectiveness Test.
To avoid contamination do not touch the pipette to the glass of water or with your fingers for any reason.