Not every sunscreen is created equal. In fact, a recent study by the Environmental Working Group (EWG) shows Vitamin A derivative retinyl palmitate included in a variety of sunscreens may speed up the growth of cancerous cells in lab mice by as much as 21 percent when combined with sunlight.

So what precautions should people really be taking with their sunscreen and sun exposure?

Sunscreen Safety and Regulations

Currently, there are no government labeling guidelines for sunscreens. In fact, legislation as been in the works since 1978, and the Food and Drug Administration is finally getting around to ruling on it this fall. However, the first federally regulated sunscreens won't go on store shelves until the summer of 2012 according to EWG.

Solid Sunscreen Options

Top scorers tested by EWG include products from Jason Natural Cosmetics and All Terrain brands. (See EWG's best-rated sunscreens.) EWG recommends lotions over sprays or powders.

According to WebMD, Consumer Reports Health tested 12 products and found four sprays that worked best at blocking harmful ultraviolet A and ultraviolet B radiation that can cause sunburns, wrinkles, and certain skin cancers.

The top four include:

- Up & Up Sport Continuous SPF 30, by Target. It is administered by spray and costs $0.88 per ounce.
- Walgreens Sport Continuous SPF 50. Also a spray. Cost, $1.33 per ounce.
- Banana Boat Sport Performance Continuous SPF 30. Spray. Cost, $1.60 per ounce.
- Aveeno Continuous Protection SPF 50. Spray. Cost, $2 an ounce.

Consumer Reports Health also did a best buy ranking of lotions and cost per ounce. “The Aveeno Continuous protection spray is one of the mildest in terms of scent and leaves a bit of a greasy residue that is fairly mild. If scent is not an issue, try the Up & Up by Target or the Walgreens Sport Continuous,” according to the May 25 issue of  Consumer Reports.

Tips for Maximum Sun Protection

Cover yourself with tightly woven clothing and a hat as much as possible. Be sure to use sunscreen with an SPF of at least 30 that is water resistant. Apply about a shot glass full 20 minutes before you go outside. Reapply the full amount every two hours or sooner, if you've been sweating, swimming or dried off with a towel.

Don’t spray or rub sunscreen on clothes; products can stain

Limit exposure in the sun and seek shade during peak heat and sun exposure

If sunscreen has no expiration date, write the purchase date on the bottle. Be sure to discard it at the expiration date, or when you’ve had the product for more than two years. After that, potency is lost.

Do additional research and consult with a doctor regarding sun protection for existing health or skin related issues or to treat a severe sunburn

Keep an eye out for any sudden changes in skin color or texture and consult a doctor

Don't forget sunglasses to ensure UV radiation protection for your eyes and use glasses that offer 100% protection