Sun protection can fall into chemical or mineral category.
SPF is not created equal. There are various types of chemicals and compounds that protect against different bands of UV radiation. UVR spectrum has 4 different lengths:
* UVC (200nm to 290nm)
* UVB (290nm to 320nm)
* UVA I (320nm to 340nm)
* UVA II (340nm to 400nm)
UVC has the shortest wavelength. It is almost completely filtered out by the ozone layer. However, if this changes in the future, our knowledge and need for sun protection as we know it today, will really change.
UVB penetrates the epidermis (the uppermost layer of the skin). It is responsible for most epidermal cellular damage. It’s ability to create erythema and sunburn.
UVA penetrates the skin to a greater depth than UVB, into the dermal layer (inner layer of the skin). It’s responsible for accelerated skin and photo ageing.
UVB radiation affects skin barrier defense system cells such as the langerhans cells (immune cells), melanocytes (cells responsible for skin color) and keratinocytes.
UVA I and UVA II have damaging effect on the collagen and elastin protein fibers of the dermis, destroying skin’s density and skin structure.
UV rays also cause vitamin depletion from the skin.
What should a good sun protection product be able to do?
* Offer broad spectrum protection (UVA and UVB)
* Contain an oil soluble antioxidant to reduce oxidative stress (like beta-carotein, lutein, lycopene etc)
* Exhibit a vitamin replacement profile (vitamins A, C and E)
* Exhibit an anti-ageing protection profile
All sun protection products and daily care cosmetics should ideally contain antioxidants.
There are two types of sun proection blocks: physical reflects the UV rays (titanium and zinc oxide); and chemical blocks that absorb or convert UV rays (like Avobenzone, Parsol 1789, Oxybenzone etc).
Many of the chemical blocks are effective only in the UVB range. There are very few with ability to cover both UVA I & II.
This is why a quality formulation usually employs a number of different overlapping types to cover the full spectrum.
FDA is updating sunscreen regulations and will become effective this summer.
By these regulations “Broad Spectrum” products will have to pass the test and will provide protection against both UVA and UVB rays. Under the new regulations, sunscreen products that protect against all types of sun-induced skin damage will be labeled “Broad Spectrum” and “SPF 15” (or higher) on the front.
The new labeling will also tell that Broad Spectrum sun protection can reduce the risk of skin cancer and early skin aging.
By contrast, any sunscreen not labeled as “Broad Spectrum” or that has an SPF value between 2 and 14, has only been shown to help prevent sunburn.
Sun causes 80% of aging. Compare the area of your body that has been protected from the sun exposure to the face or hands that are in most times always exposed to the sun, and you will be able to see the difference in skin’s elasticity, structure and overall health. Protect your skin with topical antioxidants, vitamins and full spectrum SPF!