And with so many new ingredients now in sunscreen it's hard to figure out what to use. That is why the government is proposing a new rating system. Along with SPF factors, there will be a star rating system, too.
One-star for the least protection and four-stars for the most. But the stars only tell you half of the story. How does a product protect you against harmful UVA rays?
"They have not yet come up with any other rating for the UVB protection other than the current SPF system," said Dr. Don Mehrabi from Glendale Memorial Hospital.
UVB are generally the rays that cause skin cancer. Dr. Mehrabi says regardless of the rating system, the first thing you need to look at are the numbers.
"The higher the SPF the more protection," adds Dr. Mehrabi.
The next thing to look for is the ingredients. Helioplex and Mexoryl are types of chemical sunscreens. Titanium dioxide or zinc are physical blockers.
A physical blocking sunscreen covers the skin and deflects UV rays. A chemical sunscreen is absorbed into the skin and neutralizes harmful UV rays.
"Either one works great. The most important factors in using a sunscreen -- is to use enough and apply it often," said Dr. Mehrabi.
Even if you're just driving into the office, Dr. Mehrabi says you still need wear sunscreen and re-apply before you go back outside.
"Car glass allows UVA to come through, but blocks most UVB. So while UVB is the primary agent known to cause skin cancer UVA is the primary agent known to accelerate aging," said Dr. Mehrabi.
Although, Dr. Mehrabi says physical and chemical sunblocks both work well, he says the new ingredients like Mexoryl and Helioplex tend to stay effective a little longer.