The Environmental Working Group (EWG) has attacked leading sunscreen brands for offering inadequate protection against UV rays or containing potentially hazardous ingredients.
The consumer group said the top selling products were some of the worst offenders in its survey of the safety and effectiveness of 1,000 branded sunscreen products.
It said none of the 41 sunscreens produced by the market leader Coppertone met its safety and effectiveness standards. The EWG also criticized Neutrogena and Banana Boat, which are the second and third largest brands, recommending only one of their 103 products.
Overall the organization claimed that 85 percent of sunscreen products with an SPF rating of 15 or more are potentially unsafe or ineffective.
This is the same figure the EWG released a year ago when it launched the first edition of its sunscreen database with 700 products surveyed.
Each of the sunscreens is rated according to a system that includes information on UVA protection, stability in the sun and potential health hazards.
The EWG said the database was compiled because of the FDA's failure to finalize safety standards it first promised in 1978.
"We've been waiting 30 years for the FDA to come up with adequate safety standards, and we're still waiting," said Jane Houlihan, vice president for research at EWG.
Industry trade body, the Personal Care products Council, quickly responded to these accusations claiming that strong FDA safety and effectiveness regulations are already in place.
John Bailey, the chief scientist at the PCPC, said sunscreens are classified as drugs by the FDA and the agency requires significant data on every active ingredient before it is approved.
"The agency also has broad authority to inspect manufacturers, require adherence to strict manufacturing practices, and enforce rigorous, science-based regulations to ensure that sunscreen products are safe and effective for consumers," added Bailey.
The industry representative said any suggestion that the FDA is purposely delaying the finalizing of sunscreen safety standards is wrong. He said scientific data must be thoroughly evaluated to make regulatory decisions that are in the best interests of consumers.
The PCPC questioned the data sources and methodology employed by the EWG and accused the organization of making an unjustified attempt to discredit an extensive, long standing body of scientific data.
The EWG is not the only organization to have raised the alarm about sunscreen products in recent times.
At the end of May, the UK magazine Which? published the results of its own investigation of SPF levels in sunscreens.
The consumer watchdog concluded that too many sunscreens, including many top brands, actually offer significantly less protection than they claim. It tested fourteen SPF 15 sunscreens including some of the top brands and found that only eleven provided a SPF of 12.5 or above.