While airplane tap water is technically "potable" and treated to meet regulatory standards, frequent flyers and dermatologists often advise against using it for facial care. The water is stored in onboard tanks that are notoriously difficult to fully sterilize, and independent studies have frequently found levels of bacteria and biofilm in these systems. For basic hand washing with soap, the water is perfectly safe as the mechanical action of scrubbing removes contaminants. However, for washing your face—especially if you have sensitive skin or open pores—the water may contain high levels of chlorine (used for treatment) and trace sediment from aging pipes, which can be extremely drying and irritating in the already arid cabin environment. For a better travel beauty routine, many experts suggest using a splash of bottled water or a pre-moistened facial wipe to cleanse your skin, ensuring you avoid exposing your face to the potential contaminants and harsh chemicals found in the aircraft's internal plumbing.