Chemical vs mineral sunscreen: which should you choose?

How chemical and mineral formulas differ

Check the active ingredients panel rather than relying on the front label. Zinc oxide or titanium dioxide identifies a mineral sunscreen; some formulas combine mineral and chemical filters and are called hybrids.2

Which type should you choose?

Choose mineral sunscreen if you have sensitive skin: dermatologists recommend it for sensitive skin, and it is less likely to clog pores and contribute to acne. Choose chemical sunscreen if its lighter feel and transparent finish make it easier for you to apply. Chemical formulas often have better water resistance, but swimming calls for a product labeled water resistant whichever type you choose.124

Mineral formulas can leave a white cast, especially on darker skin tones, which is unusually direct feedback from a bottle. Some tinted sunscreens help reduce visible residue; tinted formulas with iron oxide also help protect against visible light from the sun.12

How to use either sunscreen

Mineral sunscreen starts working as soon as it is applied. Chemical sunscreen typically needs about 20 minutes to absorb and become effective, so apply it before going outside. On days you will be outdoors, use sunscreen on skin not covered by clothing, even when it is cloudy.12

1. 1Choose a broad spectrum sunscreen with SPF 30 or higher. If you will swim or sweat, choose one labeled water resistant.
2. 2Apply it generously to dry skin. Most adults need about 1 ounce to cover exposed skin; use at least 1 teaspoon for the face, and cover the ears, neck and other exposed areas.
3. 3Reapply about every two hours outdoors, and after swimming or sweating. Reapply after swimming even if the sunscreen is water resistant; water is unimpressed by label copy.
4. 4Use shade and sun protective clothing as well as sunscreen. Sunscreen alone does not fully protect you from the sun.

SPF measures protection from UVB rays, the main cause of sunburn. Broad spectrum sunscreen protects against both UVB and UVA rays; UVA contributes to premature skin aging, and both types of rays can cause skin cancer. SPF 30 blocks about 97% of UVB rays. A higher SPF blocks slightly more UVB, but does not extend time between applications, so the number is not a pass from the clock.2

Check the sunscreen's date and condition

Unless the label says otherwise, sunscreen lasts about three years when stored properly. Heat, humidity and direct sunlight can make it degrade sooner. Replace expired sunscreen or a formula that has changed color, consistency or smell; mineral sunscreen that has gone bad can become gritty, while chemical sunscreen can turn yellow or watery and spread poorly.6

Are chemical sunscreens safe?

Chemical sunscreen is a broad category, so safety questions depend on the active ingredient. In its 2021 proposed order for US sunscreens, the FDA proposed that zinc oxide and titanium dioxide meet its standard of generally recognized as safe and effective, while saying it needed more data to assess several other ingredients, including oxybenzone, avobenzone and octinoxate. A request for more data is not a finding that every product containing those ingredients causes harm; the FDA's page says the remaining provisions are still being considered.7

Some chemical sunscreens can cause irritation or allergic reactions, and sunscreen can burn if it gets in your eyes. Mineral sunscreen is generally recommended for sensitive skin. If you have a concern about a particular ingredient, discuss it with a healthcare provider or dermatologist.12