Sunscreen Facts

Slip slop slap - is it really as easy as that? The more sunscreen facts you know, the better informed you'll be when choosing sun care products for you and your family. Using sunscreen has become one of the easiest forms of sun protection we all rely on today in order to keep our skin safe from sun damage. These days there is quite a lot of information about what is good and what isn't when it comes to choosing a sunscreen. The following aspects will hopefully highlight areas requiring your attention when choosing sunscreen, as well as how best to use them for ultimate protection.

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How sunscreens actually work

Sunscreen absorbs, reflects or scatters UV light rays. The UV light rays are divided into three wavelength bands - ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC). Only UVA and UVB rays reach the earth. Sunscreens provide either physical or chemical protection, or a combination of both, from these UV light rays:

  • Physical sunscreens form an opaque film on your skin that reflects or scatters UV light before it can penetrate the skin. These sunscreens contain ingredients, such as zinc oxide and titanium dioxide, which protect against both UVA and UVB rays. Original formulations of physical sunscreens remained white when applied to the skin. Newer formulations have reduced the size of the molecules and enable them to blend more with your skin tone and so are less obvious.
  • Chemical sunscreens are absorbed into the skin, from where they absorb the UV rays before they can cause any sun damage. They contain one or more ingredients, such as avobenzone or oxybenzone, which absorb UVA or UVB rays. For broad UV protection, chemical sunscreens will often contain more than one ingredient in order to be able to protect against both UVA and UVB rays.

SPF and it's meaning

Easily the one sunscreen fact that most people judge a sunscreen's value by is the SPF, which stands for "sun protection factor". This appears on sunscreen packaging as a number, which declares the amount of protection the sunscreen has been tested and certified for. This rating ranges from as little as 4 to as much as 100.

An SPF under 15 is usually used by those who don't require much protection due to dark skin pigment, or as added protection in such things as a daily face moisturizer or foundation.

Another sunscreen fact is that the most common SPF ratings in sunscreens are SPF 15 and SPF 30. If you don't tend to burn easily when out in the sun, or are already reasonably well tanned, you can choose a sunscreen product with SPF 15. Those with fair skin or who have the tendency to burn easily, should rather opt for a sunscreen with at least an SPF of 30.

From the table below, you can see that the SPF protection curve rises sharply and then trails off. Here are sunscreen facts that are not commonly known... An SPF of 30 will provide 97% protection, whereas an SPF of 50 only provides for a little more protection, as in 98%. This graph also illustrates how an SPF of 30 does not double the protection of an SPF15, or an SPF 60 double an SPF 30 which are commonly asked questions.

Another interesting sunscreen fact around SPF is that if you apply SPF 15 over an SPF 30, you will only have a maximum protection of SPF 30. Not, as some people believe, a combined SPF of 45.


Fig 1. SPF Coverage

spf-coverage

What SPF do I need?

Very much part of any interest in sunscreen facts should be getting to know your personal skin type and how it reacts to exposure to the sun. This is key to knowing what SPF to acquire.

Typically, a fair skin needs greater protection than a darker skin as a darker skin has more melanin content. As we 'tan', so the melanin increases and we obtain a greater level of protection. If your skin does not tan well at all, it is imperative to choose at least an SPF of 30 and reapply often. If your skin tans reasonably well, take it slowly and allow your skin the time it needs to build up a tan. This means you can start with at least an SPF of 30, reapplying as required, and when your tan is well established, reduce to an SPF of 20 or even 15.

Many dark skinned people do not bother with sunscreen. However, if not wishing to deepen their dark coloring, obtain dark spots, or age prematurely, they will opt for a sunscreen and usually an SPF of 15 is sufficient.

Using an SPF higher than SPF30 is a choice that usually requires spending more to obtain the higher SPF, but knowing that the increase in cost will not match the increase in protection. Reapplication is a better assurance here.

In any of the above choices, the main objective is not to burn your skin. Even black skinned people will get sun burnt and therefore are susceptible to skin cancers and the dreaded melanoma.

The American Academy of Dermatology recommends that, regardless of skin type, a broad-spectrum, water-resistant sunscreen with an SPF of at least 30 should be used year-round.

Broad Spectrum protection

Sunscreen facts about 'broad spectrum' vary in many people's minds. What it actually should mean is that you get protection from all of the long-wave UVA and the medium-wave UVB rays. Protection from the short-wave UVC rays is not included as they are prevented from reaching the earth's surface by the hemisphere.

Unfortunately, many sunscreens that say that they are broad-spectrum really aren't at all, or don't block all the rays from the full UVA spectrum. Ie. The full wavelength spectrum from 290 - 400 nm. (see figure below)

To get good protection from UVA rays as well as UVB, look for sunscreens that list titanium dioxide, or zinc oxide as one of their ingredients.

uv-rays

Sunscreen and expiry dates

Sunscreen facts presented on any tube of sunscreen should provide the relevant information about when it will expire. This will relate directly to the ingredients contained within the cream or spray. Whether a chemical or physical based sunscreen or a combination of both, there will be a limit as to how long they will be effective.

Another sunscreen fact from an expiry point of view, is that the better you look after your sunscreen, the more likely it will last. Eg. taking it to the beach and leaving it out in the full sun for hours on end will most likely create some sort of impact. Whereas if you make a point of keeping it relatively cool and not exposed, you are likely to retain the quality longer.

Applying sunscreen

As a general rule with all sunscreens, apply 20 minutes before going out into the sun and reapply every 2 hours. However, if you have a physical sunscreen, upon application, it will sit on the skin and create a barrier that reflects the sun's rays, so it is actually liable to work almost immediately upon application. Chemical sunscreens are absorbed into the skin and so will require a longer time beforehand for application to allow them time to absorb. Often a sunscreen will contain both, so hence the general rule is to apply 20 minutes before exposure.

It is also important to remember that physical sunscreens only last until you wipe it off or sweat it off. Chemical sunscreens in general become less effective once exposed to the sun. So reapplication often is vital for optimal protection. If you plan to get wet or sweat excessively, you can choose a sunscreen that is more water resistant than most, but bear in mind the fact they are not likely to be completely waterproof.

What many people fail to do is properly is to protect their entire body when applying sunscreen. While you should definitely apply sunscreen to the areas of your body that will be exposed to the sun, it is also important to add a layer of sunscreen to your hands, fingers, feet, toes, behind the ears, and the back of the neck. These are common areas that are often forgotten and very often the areas that get sun burnt, as well as skin cancers. Sunburns in these areas can also be particularly uncomfortable.

Natural sunscreens with additional Organic ingredients

For those that enjoy using organic products, where sunscreens are concerned, there has been some great progress towards production of healthier, nonchemical based, non-toxic sunscreens. This type of sun protection brings its own set of sunscreen facts with it. Due to the concern over certain sunscreen ingredients being potentially toxic to humans, many now turn to non-chemical, non-toxic versions of sunscreen, which only contain ingredients that are safe for use on humans and are formulated to be gentle on even the most sensitive skin. They also carry an SPF rating and many are specially formulated to cater to all skin types.

With these sunscreen facts in mind, you should be better informed on the type you can buy and how to use it properly.

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