What is a Sunscreen?

What is a sunscreen? A sunscreen according to Merriam-webster.com is a "preparation (as a lotion) applied to the skin to prevent sunburn (as by chemically absorbing ultraviolet radiation); also : its active ingredient (as benzophenone)". Generally, any product that blocks ultraviolet rays when applied on the skin can be termed as a sunscreen.  

It is important to note that even clothing and hats that prevent the sun rays from coming into contact with the skin are sunscreens.  

Basically, sunscreens come in different formulations including lotions, cream, spray, films, liquid, ointments, sticks and gels. 

Sunscreens act by scattering, absorbing or by blocking the ultraviolet rays thus the skin is protected from damage.

A good sunscreen should provide protection against both ultraviolet-B rays (UVB) and ultraviolet-A rays (UVA). The exact amount of UVB and UVA that is blocked by a sunscreen differs between different sunscreens. Sunscreens are considered to be particularly important for people who live in the tropics. They are also widely used during summer in countries that are not in the tropics. 

Some people mistakenly believe that only people who are fair-skinned should use sunscreens. This is a wrong perception; sunscreens should be used by all people regardless of their skin color which means that even dark-skinned people should use sunscreens. 
Basically, so long as one will be exposed to sunshine, he or she should apply the sunscreen before leaving the house. Dermatologists also recommend the use of sunscreen even on days when it is cloudy as even on such days there are ultraviolet rays that reach the earth's surface. 

There are several benefits of a sunscreen and these include: preventing sunburns, delaying aging (anti-aging) and preventing skin cancer. 

For your information, in the US sunscreens are classified by the FDA as drugs due to their role in ensuring a healthy skin. 

What is the difference between a Sunscreen and a Sunblock? 

 

Many people use the terms 'sunscreen' and 'sunblock' interchangeably without realizing that they are somewhat different. However, the differences are minor as the two basically perform the same function: they protect the skin from harmful ultraviolet radiation. So, how does a sunscreen differ from a sunblock? A sunblock has a sun protection factor (SPF) of 15 or less. On the other hand, a sunblock has an SPF of 30 or more. This means that a sunscreen and a sunblock differ based on their SPF. Sunblocks and sunscreens also differ from one another based on their ingredients. Common sunscreen ingredients include: cinnamates, benzoyl methanes, para-aminobenzoicc acid (PABA), salicylates, and benzophenone. Common sunblock ingredients include: titanium dioxide and zinc oxide.