On July 6th, the 4th annual Environmental Working Group's (EWG) 2010 Sunscreen Guide became a free iPhone application, EWG Sunscreen Buyer's Guide.

Next time you find yourself at the drug store or hotel sundry shop staring at rows sunscreens packages covered with marketing jargon and healthy claims, there is no need to guess which products are effective and more importantly won't cause health problems.

Simply make a few taps on your iPhone and find "EWG's top-rated sunscreens for broad-spectrum protection with fewer hazardous chemicals that penetrate the skin", also you can search to see how your sunblock has been rated and find 'sun safety tips'.

Each block's ratings can be viewed for UVB protection (SPF), UVA protection, UVA/UVB balance, sunscreen stability and health concerns. Plus a list of the ingredients with 'recommend', 'caution' and 'concern' rankings by each.

Unfortunately only 8% of all the blocks on the market are effective and healthy.

Only 39 products meet EWG's health standards in that they do not tout "exaggerated SPF claims above 50", contain any "potentially hazardous ingredients, in particular recently developed government data linking the common sunscreen ingredient vitamin A [often labeled as "retinyl palmitate"] to accelerated development of skin tumors and lesions."

Also no "products with oxybenzone, a hormone-disrupting compound which penetrates the skin and enters the bloodstream" will be found on the top blocks list.

The highest scoring products were mineral based containing zinc or titanium.

Download the EWG Sunscreen Buyer's Guide application via iTunes and if you don't have an iPhone you can access all of the guides online, including:

Top beach and sport suncreens
Top SPF lip balms
Top SPF moisturizers
Top SPF makeup