There are two categories of sunscreens: physical and chemical. Avobenzone falls into the chemical-based sunscreen category. Understanding the difference is essential when determining which product is right for you.
PHYSICAL SUNSCREEN
Physical sunscreens work by absorbing the UV rays from the sun and transferring it into heat.
Physical sunscreens are often described as working by reflecting the UV rays from the skin. This isn’t technically true; while physical sunscreens do reflect UV rays, they only reflect about 10% of the rays. The rest of the UV rays are absorbed and converted into heat, precisely like chemical sunscreens. The heat produced from this action is negligible and doesn’t damage the skin.
These types of formulations rely on ingredients such as zinc oxide and titanium dioxide to provide this protection. Physical sunscreens create a barrier between the skin and the sun and aren’t absorbed into the skin. They are generally broad-spectrum, which protects against both UVA and UVB rays. Physical sunscreens are designed to sit on top of the skin, so they often leave a white cast on the skin when used correctly.
CHEMICAL SUNSCREEN
Chemical sunscreens are absorbed into the skin and absorb the sun’s harmful rays before they can penetrate deep enough to cause damage to the skin.
Often chemical sunscreens are used in combination with another chemical sunscreen to provide broad-spectrum protection. In the case of avobenzone, it is commonly used in conjunction with UVB blocking ingredients as it works best in preventing damage from UVA rays.
Also, both types of sunscreens, physical and chemical, will often include ingredients such as vitamin C or E to protect against damage from free radicals.