Mineral sunscreen: 4 label checks

What should you check on a mineral sunscreen?

The word "mineral" on the front is just the start. ☀️ Flip it over and check four things: the active ingredients, SPF and broad spectrum, water resistance, and the directions.

The two mineral filters are zinc oxide and titanium dioxide.

Reference: US FDA, 2019

This guide is about sunscreen you rub onto your skin. 🧴 Breathing in a powder or swallowing something is a different kind of exposure, with different findings. The titanium dioxide page explains that one, exposure route included.

How do you read the label?

Turn the tube over. 🔄 Four checks cover most of it: the active ingredients and their percents, SPF and broad spectrum together, water resistance, and how much to put on and how often.

1. Read the active ingredient panel

Look for zinc oxide, titanium dioxide, or both, in the "Active ingredients" box on the back. 🔍 That box tells you more than the front of the tube.

Write down each active and its percent. A filter name alone doesn't tell you the SPF. The SPF printed for the finished sunscreen does.

2. Read SPF and broad spectrum together

SPF is about protection from sunburn. "Broad spectrum" means protection from both kinds of UV light, UVA and UVB. 🌈 Look for both words.

The American Academy of Dermatology suggests broad-spectrum, SPF 30 or higher, and water resistant.

Reference: American Academy of Dermatology

3. Check for water resistance

Going swimming or getting sweaty? 🏊 Check whether the label says "water resistant".

If it does, read how long it lasts in water. In the US the label can say only "40 minutes" or "80 minutes". ⏱️ Put more on after that many minutes of swimming or sweating. Words like "waterproof" or "sweatproof" are not allowed on a US sunscreen label.

Reference: US Food and Drug Administration

4. Follow the amount and the repeat directions

Put it on before you go outside. Put more on about every two hours, and after swimming or sweating. ⏰

Reference: American Academy of Dermatology

Here's the sneaky part: most people use too little. 😮 A review found people often put on only about one fifth to one half of the amount used in SPF tests.

Reference: Petersen and Wulf, 2014

So follow the amount on the label, and don't skimp.

What if a sunscreen has no water-resistance claim?

Then save it for days without a pool. 🏊 A US sunscreen with no water-resistance claim has to tell people to use a water-resistant sunscreen when they swim or sweat.

So for the beach, the gym or a hot day outside, reach for a tube that says water resistant and shows its minutes.

Reference: US Food and Drug Administration

For swimming, pick a tube that says water resistant, with 40 or 80 minutes.

How much sunscreen does your body need?

About one ounce to cover the whole body, says the American Academy of Dermatology. 🧴 Most people use less than that, so it's worth measuring once.

Put it on before going outside, then add more about every two hours, and again after swimming or sweating.

Reference: American Academy of Dermatology

With too little, skin gets less protection than the SPF number on the tube says. 😮

Reference: Petersen and Wulf, 2014

About one ounce covers the body. The sun protection page lists the filters with the most study behind them.

For a routine built from your own skin answers, take the free skin quiz.