Summer means spending time in the sun. Instead of buying bottle after bottle of sunscreen, consider making your own.
WonderHowTo has a brief guide on how to make your own sunscreen. The key ingredient here is the zinc oxide. In sun screen, zinc oxide is used to scatter light waves in the UV-A spectrum. As Physics.org explains:
Sunscreens help to filter out UV radiation using a combination of two main types of active ingredients. Inorganic particles, such as titanium dioxide or zinc oxide, form a physical barrier, reflecting or scattering UV waves. Organic components meanwhile absorb UV rays and release their energy as heat.
The recipe provided is unlikely to have the same shelf life as a commercial sun block, but is bound to appeal to DIY enthusiasts. Check out WonderHowTo for the full recipe.
How to Make Your Own Non-Toxic Sunscreen at Home [WonderHowTo]