How long is mineral sunscreen good for?

How do you know when the bottle expires?

Start with the date on the container, rather than treating three years as an automatic allowance for every bottle. US sunscreen must maintain its original strength for three years, but a printed expiry date tells you when to stop using that product. If there is no date, write the purchase date on the container so you can track the three year limit.13

The label differs by market: Canadian sunscreens have expiry dates, while UK bottles can show an open jar symbol with a number and the letter M to indicate how many months the sunscreen lasts after opening. Follow the information on your own container. An unopened bottle is not a reason to ignore a printed expiry date.124

Does mineral sunscreen last longer?

Mineral sunscreens use zinc oxide, titanium dioxide or both as UV filters. These filters are photostable, meaning they remain stable under light exposure. That property does not give the finished sunscreen an unlimited shelf life: use the same expiry and storage rules rather than extending the date because the bottle says mineral.256

When should you replace it early?

Sunscreen can spoil before its expiry date. Replace the bottle if you notice any of these changes:3

• The colour has obviously changed.
• The smell is different or foul.
• The product has separated into distinct layers, such as oil and a solid.
• The consistency has become dry and flaky.

Do not keep using expired sunscreen just because there is product left. Protection can decline, and expired sunscreen can cause irritation or an allergic reaction. Bacteria or mould can also grow inside an old container.23

How should you store mineral sunscreen?

Keep sunscreen out of direct sunlight and away from places that reach high temperatures, including a hot car. Extreme heat can make sunscreen less effective and cause it to spoil sooner. The label's 'Other Information' section includes storage instructions, despite sounding like the drawer where the label put everything it could not organise.123

How long does mineral sunscreen last on your skin?

The bottle's expiry date and the reapplication interval answer different questions. A bottle that is still in date needs regular reapplication once the sunscreen is on your skin. A higher SPF does not extend the time between applications. Water resistant sunscreen still needs reapplication after swimming or heavy sweating, and sunscreen can also rub off.245

1. 1Choose a broad spectrum sunscreen with SPF 30 or higher and water resistance.
2. 2Apply generously and evenly to exposed skin at least 15 minutes before going outdoors, following your bottle's directions.
3. 3Reapply at least every two hours during sun exposure.
4. 4Reapply sooner after swimming, sweating, towel drying or rubbing the sunscreen off.

Sunscreen labels carry usage directions as well as storage information, so the small print has responsibilities beyond making the packaging look busy.1

What if sunscreen causes a reaction?

If sunscreen causes a rash, itching or another reaction, stop using that product and try a different type or brand. Speak to a health care provider if you are concerned about the reaction or need help choosing a replacement. Before using a new sunscreen, especially on sensitive skin, test a small area of the inner forearm and check for a reaction after 48 hours.2