How Does Sunscreen Work

How does sunscreen work? Well it basically helps to block the sun’s harmful UVA/UVB rays. UVA rays are the deeper penetrating and cause wrinkles and premature aging of the skin.

And UVB rays are the ones that cause most of the burning/radiation of the skin.

A sun protecting product can interfere with sun damaging rays can in two ways, by blocking them either chemically or physically. 


The physical blocking ones use inorganic ingredients like zinc oxide or titanium oxide which block and reflect the sun's rays.

The chemically based protectors use organic ingredients like octyl methoxycinnamate (OMC) or oxybenzone to absorb the radiation.


However, this process is now under intense scrutiny by the EWG.....who question the safety of these chemicals on our skin. Sun Safety for more information.

Sunscreens are labeled with SPF levels. SPF stands for the Sun Protection Level. The higher the number of the SPF factor, the better the sunscreen filters out the UVB rays.

Just remember.................a sunscreen with an SPF of 30 is not twice as good as one with an SPF of 15.

A sunscreen with an SPF of 15 will block out about 93% of the sun’s ultraviolet rays where as one with an SPF of 30 will block about 97%.

Most regular sunscreens offer little protection from the sun’s UVA rays. What you really want to look for, when choosing a sunscreen is a broad spectrum sunscreen.

A broad spectrum sunscreen offers protection from both UVA and UVB rays.

Sunscreens are best when used every day especially if you are going to be spending more than twenty minutes out in the sun.

You should being applying a good sunscreen thirty minutes before going out.

How Does Sunscreen Work - Does Sunscreen Expire?

Yes, so make sure to read the bottle to find the expiration date. You can usually find this on the bottom of the bottle or on the side.

Unfortunately, they make this date so very tiny – it’s often very hard to read -- especially, if the product is on sale. So be careful when buying a product that is deeply discounted!

Generally, manufacturers are required to make sure that their product is stable for up to three years. So if you have some left over from the previous year or two, you should be ok to use.

But, if you do have a bottle left over with an older date…..it makes me wonder if you’re using it enough and properly.

Remember, in order for a sun protection product to work properly you need to use enough of it to cover all exposed areas. That means you have to use about an ounce – which is about a shot glass full.

Sunscreen Statistics - Did You Know..........

And speaking of left over sun product, it seems that many people still don’t protect themselves from the suns rays. 

Did you know that according to the Consumer Reports National Research Center, up to 31% of Americans polled say they never wear sunscreen.


And, up to 12% of children under 12 hardly ever wear sunscreen!

With what we know about the dangers of excess sun exposure, the importance of protection and cancer prevention – that statistic almost seems criminal.

Additional Reading

Best Sunscreen - What is the best sunscreen? Find out here.

Safe Sunscreens - Click here to see a list of safe sunscreens.


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