The study looked at name-brand sunscreens and worked towards a database that lists products, outlining the ones that offer the best combination of both safety and effectiveness.
According to the EWG this criteria takes into account sunscreens products that are deemed to have been formulated with 'safe' ingredients, as well as having the highest rate of protection against sunburn, preventing the effects of longer-term damage to the skin.
The EWG claims that 85 per cent of the products it assessed with SPF ratings of 15 or more actually offered less than satisfactory sunburn protection or contained potentially unsafe ingredients.
The report highlights the fact that the complex formulation of sunscreens can lead to a number of problems that are sometimes overlooked by formulators, one of which is the fact that sunscreen chemicals can break down when exposed to the sun's rays and have to be formulated with stabilizers.
Another potential problem, according to the group, is that some formulations, particularly those using nanotechnology, contain particles that are so small they can penetrate the skin presenting as yet unknown health risks.
The EWG says its research is based on nearly 400 peer-reviewed studies of the 17 sunscreen chemicals approved for use in the US, a study on sunscreen ingredient toxicity, as well as a product-by-product assessment of protection from UVA and UVB radiation.
"Our research shows that some products are far more effective than others, while presenting fewer safety concerns," said Jane Houlihan, vice president for research at EWG.
The results of the combined studies have been compiled on the group's websites, which is aimed at informing consumers about which products are deemed to be safest and which are not.
"EWG has conducted this research because the FDA has failed to do so," Houlihan added.
The group also underlines the fact that in response to this lack of regulation, US citizens have since filed nine class-actions against advertising standards in California, while the Connecticut Attorney General has petitioned the FDA to set standards and six senators have petitioned the FDA - all urging for a review on sunscreen regulations.
In the face of lobbying from interest groups such as EWG the Cosmetic Toiletry and Fragrance Association (CTFA) has launched an online database, through its Online Infobase, which is claimed to provide reliable information on cosmetic ingredients that is backed up by balanced scientific study.
The subscription service provides information on all chemicals that are regulated by the FDA for use in personal care formulations.