Sunscreen
Sunscreen refers to products that allow the Sun's rays to penetrate the skin but filter some of the radiation in the ultra violet spectrum. The UV rays get altered to a safer wavelength and are released. The chemical interaction between the sunscreen and UV allows the sunscreen to absorb the UV before it penetrates the skin.
Sunscreen offers protection from UV-A and UV-B, however sunscreen ingredients have the ability to deteriorate at a faster rate once exposed to sunlight, hence some radiation is able to penetrate to the skin. Some sunscreen products offer no protection against UV-A radiation whatsoever. Products often contain a mixture of physical and chemical block ingredients.
Sunscreen offers protection from UV-A and UV-B, however sunscreen ingredients have the ability to deteriorate at a faster rate once exposed to sunlight, hence some radiation is able to penetrate to the skin. Some sunscreen products offer no protection against UV-A radiation whatsoever. Products often contain a mixture of physical and chemical block ingredients.
UV Protection
SPF
SPF stands for Sun Protection Factor and shows to what degree a product prevents sunburn. Since sunburn is caused by UVB radiation, SPF rating give no indication of how well a product will protect you from UVA radiation (responsible for skin aging and skin cancer). A higher value means you get more protection. As sunburn is caused by UVB radiation SPF is only a measure of how much UVB is blocked, not how much UVA. So while you may be using the highest SPF available, you are still completely vulnerable to UVA radiation - which causes skin cancer and skin aging. For protection against both UVA and UVB rays you will need a 'broad spectrum' product.
What SPF should I use?
When choosing an SPF rating, keep in mind that doubling the SPF value doesn't mean you get double the protection. SPF 15 will block the majority of UVB rays, SPF will block more, and anything over SPF 30 doesn't really protect you much more than an SPF 30 product.
SPF 15 blocks roughly 93% of UVB.
SPF 30 blocks roughly 97% of UVB.
When choosing an SPF rating, keep in mind that doubling the SPF value doesn't mean you get double the protection. SPF 15 will block the majority of UVB rays, SPF will block more, and anything over SPF 30 doesn't really protect you much more than an SPF 30 product.
SPF 15 blocks roughly 93% of UVB.
SPF 30 blocks roughly 97% of UVB.
Broad Spectrum
Sunscreens that prevent at least some of both UVA and UVB rays from damaging your skin are called 'broad spectrum'. When choosing which product to buy look for one which states either "broad spectrum" or that it blocks both UVA and UVB. Even though a product may display the term 'broad spectrum' it may not block all UVA and UVB radiation, check the ingredients to find out more.
Sunscreen Effectiveness
How well you are protected depends on what product you use and how you use it. If you are constantly going in and out of the ocean or pool, sunscreen may need to be re-applied after every dip depending on how waterproof it is. Heavy sweating and toweling off can also wear off a sunscreen.
Application
General instructions that apply to most sunscreens (this may be different for the products you use, so always read the instructions.
- apply to dry skin
- make sure to cover your face, ears, neck and shoulders
- apply 15 to 30 minutes before going in the Sun
- re-apply after toweling off, swimming, or heavy sweating
- re-apply roughly every 2 hours
- apply to dry skin
- make sure to cover your face, ears, neck and shoulders
- apply 15 to 30 minutes before going in the Sun
- re-apply after toweling off, swimming, or heavy sweating
- re-apply roughly every 2 hours
Expiration
If a product has past its expiration date it may offer no protection at all, and may even be harmful. Some sunscreen will last for only a few months before opening. Other will last a few months after opening, and some will last for a year or more either way. Always check the description and date on a bottle before using it.
Sunscreen Ingredients
The active ingredients in sunscreens can be physical, chemical, or a mixture of both. Some ingredients have been proven to be harmful, such as PABA. Which is why you may notice some brands stating 'does not contain PABA'. PABA was very common in sunscreens in the past, but has been largely abandoned by manufacturers because of it's harmful affects.
There are thousands of sunscreen products available, they differ in look, feel, and scent, how they rub in, but they mostly use the same ingredients. Here is a list of some of the most common sunscreen ingredients and how they protect you.
Physical Sunscreens
A physical ingredient sits on your skin's surface forming a protective barrier and doesn't have the ability to be absorbed into your skin. Light is either absorbed into the ingredient or reflected away from your body back into the atmosphere similar to a mirror or tin foil.
Physical Sunscreen Ingredients
Titanium dioxide
Titanium dioxide offers protection from UVB and short UVA radiation, but not long wave UVA. Titanium dioxide is also non-irritating.
Titanium dioxide offers protection from UVB and short UVA radiation, but not long wave UVA. Titanium dioxide is also non-irritating.
Zinc oxide
Zinc oxide offers broad-spectrum protection (UVB and most of UVA). Arguably the best broad-spectrum protection available.
Zinc oxide offers broad-spectrum protection (UVB and most of UVA). Arguably the best broad-spectrum protection available.
Chemical Sunscreens
Some of them absorb (soak up) the ultraviolet light as it tries to pass through them Chemical sunscreens are not immediately effective, requiring a 20-30 minute delay after application before it becomes effective, whereas physical sunscreens are immediately effective. A chemical sunscreen ingredient absorbs sunlight to prevent sun damage but is also absorbed into your skin. Some people experience allergic reactions and burning eyes when perspiring.
Chemical Sunscreen Ingredients
Aminobenzoic Acid (PABA)
PABA protects against UVB but not UVA. It was discovered to have harmful health effects and so its use is highly discouraged.
PABA protects against UVB but not UVA. It was discovered to have harmful health effects and so its use is highly discouraged.
Avobenzone
Extensive UVA and limited UVB.
Extensive UVA and limited UVB.
I am a huge fan of finding sun care products that are combining active skin care ingredients to yield a protective and maintaining effect on the face and body, these products are an especially good way to approach your daily sunscreen regimen....THESE ARE A FEW OF MY FAVORITES:
