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Our sun gives off energy in the form of light and heat. This energy is measured in waves (kind of like the waves on the ocean). Some waves are short and fast; others are long and slow. This is called “wavelength.” The energy in sunlight covers a wide range of wavelengths including ultraviolet radiation (invisible light). You've probably seen the terms UVA and UVB when you look on a bottle of sunscreen.
- UVA Rays
Ultraviolet A (UVA) rays penetrate deeper into the skin and can produce tanning. These are the rays that cause wrinkles and premature aging of the skin. Lengthy exposure to UVA can also cause a sunburn and are potentially carcinogenic.
- UVB Rays
Ultraviolet B (UVB) rays are shorter and stronger than UVA rays and are mainly absorbed by the skin's surface. UVB rays can also cause a tan but are the primary cause of sunburn and skin cancer. These rays can cause Malignant tumors, such as basal and squamous cell carcinomas and melanoma.
Chemical vs Physical Sunscreen:
Sunscreens can be broadly classified into two categories: chemical sunscreens and physical sunscreens. Chemical sunscreens absorb UV radiation while physical sunscreens act by physically blocking it. Chemical sunscreens can be UVA or UVB absorbers. Many sunscreens have a combination of ingredients and may contain both physical and chemical sunscreens.
Chemical sunscreens provide a protective layer of sunscreen ingredients that absorb ultraviolet radiation. When UV light is absorbed by the sunscreen, the most common reaction is for its energy in the form of sunlight to be converted to heat, which is then dissipated.
Physical sunscreens block both UVA and UVB radiation from penetrating the skin by providing a reflective barrier to the sun's rays. The two most common physical blockers of UV radiation are Titanium Dioxide and Zinc Oxide.
Advantages of Mineral based Sunscreens:
- Minerals provide a reflective barrier to the sun's rays, reflecting harmful UV- A, B and C rays without the need for chemical filters.
- Mineral sunscreens are physical sunscreens and are immediately effective upon application. This is different from chemical sunscreens that need to soak into your skin in order to be effective and thus require that you apply it 30 minutes prior to sun exposure to become effective.
- Mineral sunscreens are ideal for sensitive skin.
- Minerals are environmentally friendly and reef safe - whereas the chemicals found in traditional sunscreens have been found to harm aquatic life.
- Safe for the whole family including babies and children age six months and up.
Interesting Facts about Chemical based sunscreens:
Recently released scientific studies by Switzerland's Institute of Pharmacology and Toxicology, conducted in 2001, prove a link between synthetic sunscreens and hormonal disturbances in the body. The chemical compounds in synthetic sunscreens have been found to accumulate in body fats and in breast milk, and, by mimicking the effects of estrogen, can induce undesirable hormonal changes. Synthetic Sunscreen Chemicals with estrogen mimicking effects:
4-Methyl-Benzylidencamphor(4-MBC), Oxybenzone, Benzophenone-3 Homosalate(HMS), Octyl-methoyl-cinnamates(OMC) ,Octyl-Dimethyl-Para-Amino-Benzoic Acid(OD-PABA)
What does SPF mean?
SPF stands for Sun Protection Factor. SPF refers to the ability of a sunscreen to block ultraviolet B (UVB) rays, which cause sunburns, but not UVA rays, which are more closely linked to deeper skin damage. Both UVA and UVB contribute to the risk of skin cancer. Broad-spectrum sunscreens protect against UVA and UVB radiation. However, SPF does not predict UVA protection.
You do get more coverage with higher SPF's but the difference between SPF 15 and SPF 100 is minimal. SPF30 - 60 offers only about 1% more protection than SPF 15. Use of these higher SPF rating is more marketing tactic than a real benefit to the consumer.
SPF Ratings and Protection
SPF 15 blocks 94-96.7% of UVB rays
SPF 30 blocks around 97.7% of UVB rays
SPF 45 product blocks about 98% of UVB rays
SPF 50 blocks 98%of UVB rays
SPF 100 blocks 99% of UVB rays
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