Does your sunscreen work? Surprisingly, 3 of 5 brand-name sunscreens either don't protect skin from sun damage or contain hazardous chemicals - or both. An Environmental Working Group investigation of 1,651 sunscreens rates the season' s best - and worst.

Some companies have responded to EWG's 3-year campaign for safer, more effective sunscreens. 70% of sunscreen products now contain strong UVA filters, compared to 29% last year. The bad news: much UVA protection is still too thin to save your skin. Don't waste your money or risk your skin on sunscreens that don't deliver. Use our 2009 Sunscreen Guide to find better products.

More than a million cases of skin cancer are diagnosed in the U.S. every year. The incidence of malignant melanoma, the most dangerous form of the disease, is escalating. Effective sunscreens are crucial to public health. But EWG's investigation reveals that they may be hard to find:

• 61 sunscreens with SPFs from 55-100+ might tempt you to stay out longer in the sun, but they block just 1-2% more sunburn rays than an SPF 30 sunscreen.
  
• Hundreds of all-day moisturizers advertise SPF protection, but 1 in 5 offers little protection from harmful UVA rays. Some break down well before the day's end. A surprising new government report attributes an increasing incidence of malignant melanoma among people who work indoors to UVA rays shining through windows onto unprotected skin.
  
• Lip cancer is most common on the bottom lip where sun exposure is most direct. Two of 5 lip balms offer poor UVA protection.

One plus for 2009: 19% fewer sunscreens contain oxybenzone, a hormone disruptor approved by FDA as an active ingredient in sunscreen.

Few sunscreens live up to their advertising claims, and the federal government is powerless to make them. The federal Food and Drug Administration (FDA) has been promising to regulate sunscreens since 1978, when gasoline was 63 cents a gallon and the BeeGees' "Saturday Night Fever" topped the charts.

In the meantime, EWG's research team has created this comprehensive guide - listing 95 recommended products and other sun safety tips - to help you and your family have fun in the sun - safely.