What are sunscreens?
Sunscreens are products that protect the skin from
damage caused by ultraviolet radiation (URN). They do this by using: organic chemicals that absorb light and dissipate it as heat; inorganic filters (blockers) that sit on the surface of the skin and act as physical barriers; or a combination of both.
Ultraviolet Radiation
USB - primarily responsible for sunburn and suntan. Long-term exposure leads to premature aging of the skin and skin cancer.
OVA - primarily responsible for premature aging and skin cancers like melanoma and basal cell carcinoma
What protection do sunscreens provide?
SPF 30 sunscreens filter 97% or more of UVA rays. In the United Stated, there is no approved evaluation of UVA protection, therefore "broad-spectrum" labeling is open to interpretation. Consumers should be educated on the ingredients that provide UVA protection. Products that contain 6% or more Zinc Oxide provide very good UVA protection.
Key points about sunscreens
- No sunscreen is "waterproof /
sweat proof." Sunscreen should always be applied to dry skin. All sunscreens start to come off during activity; it is important that sunscreen be reapplied after towel drying. Products labeled as "waterproof" in the United States have completed an 80-minute still-water bath test. Products labeled as "very water resistant" in Australia retain their SPF after 240 minutes in moving water. Australia does not allow the use of "waterproof" or "sweat
proof," and the FDA has asked for voluntary removal.
- No sunscreen provides "all-day protection." As stated, chemical absorbers work by absorbing light, but they can be photo unstable. For example, Avobenzone loses 36% of its effectiveness within the first 15 minutes of sun exposure. Inorganic filters (Zinc Oxide and Titanium Dioxide) adhere to the skin but can be removed during towel drying. Australia does not allow the use of "all-day protection." Moreover, the FDA has asked for voluntary removal of this label claim.
- High SPF sunscreens don't necessarily offer broader or better protection. SPF only indicates the amount of UVB protection a product
provides and does not indicate how much if any UVA protection is provided. the consumer needs to understand that the specific formulation of
the sunscreen determines the amount of protection provided. Zinc Oxide products (6% or higher) provide very
photostable UVB and UVA protection. High SPF products (i.e. SPF 45, 55, 60) typically contain high levels of organic chemicals that can increase the potential for irritation and absorption, especially in children. Higher is not always better, which is why
Australia limits SPF label claims to 30+.
- No sunscreen offers complete protection against the sun. Therefore products using the term "Sun
block" are a misnomer as they allow some UV to penetrate the skin. A product that contains Zinc Oxide does provide blocking (reflective) capabilities but even Zinc Oxide, unless applied as a paste, allows a little UV light to penetrate the skin.
|
