Check This Symbol on Your Skincare and Sunscreen Before Using It This Summer, Experts Warn [UK 2026]

Health experts and consumer groups are urging people across the UK to check a small but important symbol on the back of their skincare and sunscreen products before using them.

The warning comes as many households prepare to use leftover products from last year, particularly sunscreens stored over winter.

What Symbol Should You Check?

Look for the Period After Opening (PAO) symbol — a small open jar icon with a number followed by the letter ‘M’ (for months).

Examples:

• 12M = Safe to use for 12 months after opening
• 6M = Safe to use for 6 months after opening
• 24M = Safe to use for 24 months after opening

This symbol tells you how long the product remains safe and effective once opened. After this period, the product can become less effective or potentially cause skin irritation due to bacterial growth or breakdown of ingredients.

Why This Warning Matters Now

With warmer weather approaching, many people are reaching for last summer’s sunscreen. However, sunscreens are particularly sensitive — their SPF protection can decrease significantly after the PAO date.

Dermatologists recommend throwing away any sunscreen that has passed its PAO symbol, even if it looks and smells fine. The same advice applies to moisturisers, serums, foundations, and other opened skincare products.

Expert Tips

• Always write the date you opened the product on the packaging.
• Store products in a cool, dry place away from direct sunlight.
• If a product changes colour, texture, or smell, discard it immediately — even if it’s within the PAO period.
• Check both the PAO symbol and the Best Before (BBE) date if the product has one.

This simple check can help prevent skin irritation, reduced protection from the sun, and wasted money on ineffective products.

What do you think? Do you regularly check the PAO symbol on your skincare and sunscreen? Have you ever used a product past its recommended date? Share your experiences in the comments below.

FAQs

Q1. What does the open jar symbol mean? It shows how many months the product is safe to use after opening (e.g., 12M = 12 months).

Q2. Is it safe to use sunscreen from last year? Only if it is still within the PAO period and has been stored properly. Otherwise, it’s best to buy a new one.

Q3. Do all skincare products have this symbol? Most opened cosmetic products in the UK must display the PAO symbol by law.

Q4. What happens if you use a product past its PAO date? It may cause irritation, breakouts, or offer reduced protection (especially sunscreen).