If I haven't used up last year's sunscreen, can I still use it this year? Will it be ineffective if I use it this year?

In the hot summer, sunscreen can be said to be a must-have item for many people's daily commuting, home travel. But if I haven’t used up last year’s sunscreen, can I still use it this year? Is the sunscreen I used last year no longer effective this year?

Can I still use last year's sunscreen if I haven't used it up this year?

It depends on the specific situation. The shelf life of sunscreen after opening is one year, which means it must be used up within one year after opening. If it is not used up after this time, it is not recommended to use it. Because the longer the sunscreen is opened, the more opportunities the paste inside will come into contact with the air, which will easily breed bacteria. Therefore, whether the sunscreen can be used in the second year after opening and not used up depends mainly on whether the sunscreen has been opened for more than one year. If it has been opened for more than one year, it is not recommended to continue using it.

Is last year's sunscreen ineffective this year?

As long as it is within the shelf life, it is still effective and is no different from a new one. Sunscreen is generally a compound that includes physical sunscreens and chemical sunscreens. The main ingredients of physical sunscreens are titanium dioxide and zinc oxide. These ingredients are very stable. As for the chemical composition, the current technology can achieve a stable level, so unless it is in a high temperature environment, it is very stable and can be used.

How long can you keep unopened sunscreen?

Unopened sunscreen can be used as long as it is still within the shelf life, but once the sunscreen has passed its shelf life, it is not recommended to continue using it, because the effect of expired sunscreen in blocking ultraviolet rays has been greatly weakened, and the ingredients in it have also changed, and applying it on the face may cause irritation to the skin. The normal shelf life of sunscreen is generally about 3 years, but now many businesses will print a bottle opening pattern on the sunscreen packaging, and write words such as 12M, 18M, etc. under the pattern. This means that the sunscreen is valid for 12 months or 18 months after opening. When you see such numbers, you will know whether the sunscreen you used last year can still be used this year.

What is the use of expired sunscreen?

1. Wipe the silver jewelry. After wearing the silver jewelry for a long time, there may be rust stains on the surface. If the sunscreen at home is expired, don't throw it away in a hurry. You can apply the sunscreen on the silver jewelry and then wipe it with a clean cloth. The oily ingredients in the sunscreen can help remove the rust stains on the silver jewelry and make it look brand new.

2. Remove pen stains from the skin. If a marker pen stain is left on your hand, it may not be easy to remove, but you can apply sunscreen to the stain and then gently wipe it clean with a tissue.