Differences between sunblock and sunscreen

Differences between sunblock and sunscreen

A tube of SPF 15 sun block lotion

Although it is a common misconception^{[citation needed]} that sunblock and sunscreen are both the same, they are not. They have similar properties and are both important in caring of the skin, sunblock is opaque and is stronger than sunscreen since it is able to block a majority of the UVA/UVB rays and radiation from the sun, thus not having to be reapplied several times a day. Titanium dioxide and zinc oxide are two of the important ingredients in sunblock.

Sunscreen is more transparent once applied to the skin and also has the ability to protect against UVA/UVB rays as well, although the sunscreen's ingredients have the ability to break down at a faster rate once exposed to sunlight, and some of the radiation is able to penetrate to the skin. In order for sunscreen to be more effective the user needs to consistently reapply at least every two hours, and use a higher SPF.^[23]

However, that distinction is mostly used for marketing, and the FDA has in fact considered banning the term "sunblock" from marketing claims as it considers it misleading.^[24]

For total protection against damage from the sun, the skin needs to be protected from UVA, UVB and IRA (Infra Red Energy). Roughly 35% of solar energy is IRA.^[25]