Almost two thirds of the hundreds of sunscreen products available to consumers are ineffective or unsafe, or both. And the SPF rating only relates to the effectiveness to block UVB rays that cause sunburn, but its UVA rays which may cause skin damage or skin cancer. Consumer Reports tested 73 lotions, sprays and sticks and discovered that 24 of the products actually protected at half the labeled SPF.

Reports of effectiveness vary with the group conducting the testing. Organizations which advocate natural products argue that the best protection is provided by mineral sunscreens which contain titanium oxide or zinc oxide – remember the white noses of childhood? These ingredients create a physical barrier protecting exposed skin.

“Chemical” sunscreens are those with active chemical ingredients such as octinoxate or oxybenzene are more effective at blocking damaging sunrays. Though research has not uncovered any adverse effects to humans using these sunscreens, the two main ingredients have been shown to cause hormonal changes in animals.

Which ever type you prefer, the American Academy of Dermatology recommends sunscreens have a SPF of 40 or higher. Shake the container well and use about a teaspoon per body part for lotions, apply two coats if using a spray. Reapply at least every two hours, and immediately after swimming.