The US Food and Drug Administration (FDA) has announced it is going to set new standards for formulating, testing and labelling over the counter sunscreen products.

The main area of concern is that currently sunscreens are not required to say anything about how effective they are against UVA, a type of ultraviolet radiation that like its cousin UVB can also cause cancer and premature skin ageing such as wrinkles and sun spots.

The current system of SPF, sun protection factor, only gives consumers an idea of the strength of the barrier against UVB. This was as a result of FDA rules set in the late 1970s.

In a statement released yesterday, Commissioner of Food and Drugs, Andrew C. von Eschenbach said:

"Under today's proposal, consumers will also now know the level of UVA protection in sunscreens, which will help them make informed decisions about protecting themselves and their children against the harmful effects of the sun."

Radiation from the sun comprises a range of wavelengths of the electromagnetic spectrum. The light we see is the visible spectrum but there are also many other types of "light" that we don't see, which lie outside the visible spectrum. One of these, which lies beyond the shorter wavelength end of the visible spectrum is ultraviolet (literally "beyond" violet). It is invisible to the human eye, but some creatures such as bees can see it and many flowers use ultraviolet "colours" to attract pollinating bees.

There are three types of ultraviolet (UV) radiation, UVA, UVB and UVC, with UVC having the shortest wavelength and UVA the longest. They all have the potential to destroy DNA in skin cells but UVC is mostly blocked out by the atmosphere and so it is only UVA and UVB that we need to worry about in terms of the risks of over exposure to sunlight.

Some exposure to sunlight is necessary for human health, it is overexposure that brings harmful effects. UVB helps the skin to produce Vitamin D, essential for healthy bones.

However, prolonged exposure to UVA and UVB causes a range of health problems, including damage to collagen fibres in the skin which accelerates aging, damage to the eyes, and suppression of the immune system. Prolonged exposure to UVA and UVB also increases the risk of skin cancer. This is because they can penetrate into cells and damage DNA.

As a protection against damage by UV light the skin tans by increasing the amount of melanin, a brown pigment that partially blocks the UV light. However, this is not enough to stop the damage that comes from prolonged exposure.

At present sunscreens are only required to show how much they protect against UVB. This is the sun protection factor or SPF rating system.

Under the new rules proposed by the FDA another rating based on stars to show the level of UVA protection would also be shown alongside the SPF.

The star system would be: one star for low UVA protection, two stars for medium, three stars for high and four stars for the highest protection available for an over the counter sunscreen.

If a sunscreen does not offer any UVA protection (and there are many on the market that do not) then the FDA wants it to carry the text "no UVA protection" near the SPF value.

The UVA rating would be based on two tests that sunscreen manufacturers will have to carry out to prove their effectiveness at protecting against UVA light. One would test the sunscreen's ability to reduce the amount of UVA it stops. The other test would measure the ability to prevent tanning and is nearly the same as the SPF test for UVB light.

The FDA also want to change the term sun protection factor to sunburn protection factor, and to have sunscreens carry a Warning statement that says:

"UV exposure from the sun increases the risk of skin cancer, premature skin aging, and other skin damage. It is important to decrease UV exposure by limiting time in the sun, wearing protective clothing, and using a sunscreen."

Deputy director of FDA's Center for Drug Evaluation and Research, Dr Douglas Throckmorton explained:

"Many consumers incorrectly believe that the only way to protect themselves from skin damage caused by the sun is to apply sunscreens."

"The labeling being proposed today strengthens the existing labeling for sunscreens by educating consumers on the added importance of limiting their time in the sun and wearing protective clothing as part of a sun protection regimen," he added.

Consumers have 90 days in which to comment on the new proposed standards.

Manufacturers will be given 12 months to comply to the new standards once they come into force, so consumers should not expect to see the new labelling before then.

A dermatologist who specializes in skin cancer who practises St Petersburg in Florida, Dr James Spencer, told the New York Times the new standards are good news for consumers:

"Now when you go to the drugstore and buy sunscreen, you will finally know what you are getting."

Dr Perry Robins, President of the Skin Cancer Foundation (sponsored among others by the cosmetics industry) also welcomed the news, saying that over 90 per cent of skin cancers are caused by sun exposure and:

"We now know that UVA plays a very direct role in skin cancer comparable to that of UVB. Therefore, introducing a UVA test method will enable consumers to know how well the product protects against UVA rays as well as UVB rays."

Skin cancer is cancer that forms in the tissues of the skin. There are mainly two types, both of which usually result from exposure to sunlight. One type of cancer is when the cells that form pigment become cancerous, this is called melanoma. The other type of skin cancer develops in cells that do not form pigment and there are two types of these cells: basal (small and round cells in the base of the outer layer of skin) and squamous (flat cells on the surface of the skin).

Skin cancer is the most common form of cancer in the United States. More than 1 million new cases are diagnosed every year.

Click here for more information on What You Need to Know About Skin Cancer (National Cancer Institute, US).

Click here for the full FDA statement.

Written by: Catharine Paddock