How should I store this mask and how long is it good for after opening?

Like most water-based cosmetic masks with active ingredients, this product should be stored at room temperature (below 25°C), away from direct sunlight and humidity — so not on a windowsill or in a steamy bathroom. Keep the lid tightly closed after each use to prevent contamination and oxidation of the tea tree oil and green tea extract.

Look for the Period After Opening (PAO) symbol on the packaging — an open jar icon with a number and "M" (e.g., "12M"). This indicates how many months the product remains stable and effective after first opening. For a mask of this type, 12 months is typical. If the texture separates, develops an off smell, changes colour significantly, or grows mould, discard it immediately regardless of the PAO date.

Use a clean spatula or spoon rather than fingers to scoop product out — this reduces bacterial introduction and extends usable life. If the mask comes in a tube, squeeze from the bottom and cap promptly. Do not dilute with water or mix other products into the jar.