DIY Sunscreen Doesn’t Work
You can search Google for a recipe for anything, including sunscreen. Places like Pinterest have plenty of instructions on how to mix natural oils with zinc oxide to protect yourself from the sun. Unfortunately, the DIY approach is unlikely to be an effective sunscreen.
Zinc oxide is the main active ingredient in these recipes. It is also the active ingredient in many legal sunscreens because it does absorb and reflect the sun’s rays. And since it is also found in diaper cream, you probably find it pleasant and safe. (There are some concerns about sunscreens , but in reality none of the sunscreens on the market are likely to pose a real health risk.)
But as chemist and educator Michelle Wong of Lab Muffin Beauty Scienceexplains , sunscreen protection from the sun has little to do with its active ingredient. To create an effective zinc oxide sunscreen, your formula needs to distribute zinc evenly, not interact with other lotion ingredients, and have the correct formula chemistry to stay in the bottle and remain effective when applied to the skin.
This is a more complex chemical problem than you might think. Beautician chemists at The Beauty Brains also answered this question , and they point out that even if you smeared diaper cream all over your face, you probably wouldn’t get very good sun protection, even if the diaper cream contains more zinc oxide. than conventional sunscreens. Manufacturing and inactive ingredients are of great importance. Wong points to one brand that gets SPF 50 from only 15% zinc oxide, while another gets SPF 15 from its 19% zinc oxide formula.
So what’s stopping you from trying the recipe and seeing if you get sunburned? Well, your experience in one day is not the same as finding out if sunscreen actually worked. Whether or not you get a burn depends on many factors besides what’s on your skin, including what time of year you get a lot of UV light and how much time you spend in the shade. Meanwhile, the wrong sunscreen can actually increase the amount of damage your skin takes from the sun, making a DIY sunscreen potentially worse than no sunscreen.
“Could you please put on the protective suit you found on Pinterest before heading out to the nuclear zone?” Wong asks in her video. This is an extreme example, but if you want something to really protect you, you should use what has been formulated and tested for this purpose.