Chemical Sunscreen

Chemical sunscreens are those that contain chemicals like oxybenzone or benzophonen-3, 4-MBC, salicylates, and cinnamates, which are free radicals that may be absorbed by the body. These ingredients are filters to reduce radiation penetration in the skin. However, free radicals can cause undue damage to the cells and are often responsible for causing cancer.

There are also studies that show 4-MBC and oxybenzone or benzophenone-3 mimic estrogenic effects in humans and rats, and are considered endocrine disruptors. These endocrine disruptors interfere with the normal hormonal functions causing adverse health effects on humans, and are believed to promote cancer growth.

One study conducted by the Food and Drug Administration (FDA), showed preliminary results on retinyl palmitate, a form of Vitamin A commonly found in sunscreens, that indicate an effect of accelerating cancer development in rats. While there is still no conclusive evidence that this will occur in humans, it is important to be aware of this ingredient.

Physical Sunblock

Physical sunblock, on the other hand, eliminates the hazardous chemicals being absorbed into your skin, creates an immediate barrier without waiting for the product to be absorbed, and typically provides greater protection than chemical sunscreens. These products generally contain titanium dioxide or zinc oxide. These ingredients physically block ultraviolet rays, don't penetrate into the skin and don't degrade over time.

Other Considerations

For those who have sensitive skin such as babies, children or those with allergies, there are other common ingredients to avoid. Sunscreens may also contain synthetic fragrance or preservatives, alcohol and para-aminobenzoic acid (PABA) or PABA ester (Padimate O or octyl dimethyl PABA). PABA may cause an allergic reaction and stain clothing.