Are chemical or physical sunscreens better? I touched on this in my Sunscreen and Make-up video, but a lot of people have been asking me to talk more about it, so I’ve expanded on the topic in this post, which comes in video form as well!
Click here for the video – scroll down for the blog post “summary” version with references and product recommendations (which is still somehow 1500+ words long…).
What Are Chemical and Physical Sunscreens?
The active ingredients in sunscreens are often divided into two categories:
- Physical sunscreen ingredients (more correctly known as inorganic sunscreen ingredients) are zinc oxide and titanium dioxide.
- Chemical sunscreen ingredients (more correctly known as organic sunscreen ingredients) are everything else.
You can have sunscreens containing only organic filters, only inorganic filters, or a combination of both.
The reason organic (carbon-based) and inorganic (not carbon-based) is a better classification than chemical/physical is that there’s overlap between how they work. Both types work by absorbing UV and turning it into heat. Inorganic sunscreens also scatter and reflect about 5-10% of the incoming UV, as do some particulate organic sunscreens like Tinosorb M, so really they should be classified as both chemical and physical.
Differences Between Chemical and Physical Sunscreens
The big differences between them that you should consider are:
SPF 50+ is pretty common with both types of sunscreen, but broad spectrum protection (that includes protection against longer wavelengths of UVA) is where there’s a difference.
Organic sunscreens give higher, photostable protection from UVA if you use newer filters like Tinosorbs S and M, and Uvinul A Plus (not yet available in the US). The more common avobenzone gives really high UVA protection, but it breaks down in UV so you have to be diligent about reapplication (although some formulas stabilise avobenzone so it breaks down slower, and you should diligently reapply sunscreen anyway if you’re spending a lot of time in the sun).