Hawaii weather stations usually advise you what sunscreen level to use. I can recall them regularly telling people 45 so I am not sure about the dermotologist claim that 30 is the limit although I do question this also. I remember Johnson and Johnson getting the bloopers award for advertising when they first introduced it.

I think fair skin people would burn with only 15 on. I am fare and would put on nothing less than 30. I plan to bullfrog on my chest this summer. Not a cancer risk thing just a wrinkle thing.

One last note. I used 3 bottles of SPF 30 a few years ago when at a SC beach (for one week). I applied it liberally (every 2-3 hrs) and actually got a tan, not burn, from it. No matter what to do, you'll get some kind of coloring from the sun.

Stephanie, a tan is a sign of sun damage.
The sun's rays penetrate into the skin and cause the skin to react by creating melanin.
No damage/irritation, no tan.
Of course redness is worse than tanning.
But the only 'healthy' tan is the artificial kind from a bottle.

The SPF 30 debate relates to diminishing returns.
Using a higher SPF, like 45, WILL provide more protection than 30.
But the point is that if you're looking at cost-effectiveness, do you want to pay more for something (SPF45)that makes a 1.1% difference in the amount of sun which gets through (versus SPF30)?

SPF8 versus SPF30 is a meaningful difference...12.5% penetration versus 3.3%.
But above 30 the improvement is simply negligible, but not zero.

Dr. M.:

A tan is a sign that the body is protecting the DNA in each skin cell with all the melanocytes in every individual cell gathering over the DNA, thus the brownish color (I took an Anatomy and Physiology class in college). If you want to actually enjoy a vacation in Hawaii or any tropical place, you have to get in the sun and therefore, you will get coloring. You do have the option of staying in a hotel room the whole time or go outside on a patio with an umbrella and cover your whole body, head to toe, with clothing, wear a hat with sunglasses and do absolutely nothing but that is not considered an ultimate vacation to most people.

Two comments: 1. I wish you medical experts would tell us where you got your medical degree.
2. My dermatologist suggests Blue Lizard. If you want his name, I will give it to you.
He also has advertisements in his office for a brand I never heard of with as very high sun screen factor. I asked him about it and he said I did not need it.
So there is more protection out there than SPF 30.

Dr M sounds like he/she knows what he/she is talking about.Having to go to a dermatologist every 6 months now since I had skin cancer.And my Dr says the same sort of thing.
Stephanie never sounds like she knows what she is talking about.There was another thread about Suntanning and she did the same thing.You just can't shut her up!!!
But the one thing that I learned the hard way-
If your skin gets color(in other words -tanned) then you are getting the rays that cause skin cancer.So no matter what you call it or how you talk your way around it, wear sunblock-ifyou stay pale,you stay safe.
And one more thing Stephanie-most people who care about their skin today and for the future,the ones who have some intelligence-make sure they use sunblock then they can go to Hawaii or wherever they want.
It is just the dummies like you that think you look good,tanned and wrinkled like some old leather bag,sitting in the waiting room at the hospital,waiting for your biopsy to come back.

Advice:

You go sit in a hotel room, I'll go out and enjoy myself. I don't tan year around and in fact I'm pale most of the year, I just have decided to not live in a paranoid state. Not everyone who sits in the sun for short periods of time will not automatically get skin cancer. Just because a medical condition happens to you does not mean everyone will get it.

A little medical background about tanning and SPF's:

It wasn't until 1979 that the FDA concluded that sunscreens could help prevent skin cancer, and developed the first rating system for SPFs.

In 1988, the American Academy of Dermatology held a consensus conference on photo aging and photo damage. The conclusion from that conference was that "there is no safe way to tan."

The color of your skin is determined by the amount of melanin it contains. This substance called melanin protects the skin from the sun's ultraviolet rays. A tan is visible proof that your skin is being damaged. When the ultraviolet radiation of the sun hits your skin, it stimulates cells known as melanocytes, which make the brown pigment called melanin. The melanocytes respond to the sun by making even more melanin to protect your skin from the sun. The melanin acts sort of like a barrier for the skin's cells and can give people the brown tint that is a suntan. Thus, tanning is the result of the damaging effect of UV radiation from the sun as it stimulates the skin.

I wanted an awesome trip to celebrate our anniversary and planned Hawaii. In April I casually had a mole check, they biopsied and it was malignant melanoma. I've had it removed, leaving a 5 inch scar. I'm thankful I was urged to have it checked. Anyway, It will be a lifestyle change for me to be more careful when in the sun. My dermatologist told me that here I should use spf 30 but when I am in Hawaii the sun will be much more intense and I should use spf 45 there. Why would anyone want to risk using anything less than at least 30 in Hawaii. I'm sure most of us think this will never happen to me but...surprise! I am looking forward to my trip in August and I will have loads of fun with activities in the sun but I will be skin smart using a high spf and reapplying often.

I live in Hawaii, my derm says use a screen with "titanium" in it. I like Hawaiian Tropics, it smells good enough to eat, LOL.

Dont forget to but suncreen on the tops of your feet if you are wearing slippahs! My neighbor is an ER doc here and says he has actually hospitalized vacationers with second degree burns on the tops of their feet!

To "OO's friends dermatologist" "Leave it on for the skin to absorb." The skin will not absorb anything, and certainly not sunblock. I think the benefit to slathering it on and leaving it there is that it dries in a nice opaque layer, not that it gets sucked into the body.

As far as sunblock expiring. The most recent stuff I have bought has an expiration date on it. I have heard in ads that you should buy new stuff - but of course that is what the manufacturer wants you to do, so I wonder about the validity.

I also keep some in the car, but I suspect this will lower its usefulness, since most medications will degrade faster at that high a heat, so why not sunblock?

I think the standard advice of buying high SPF sunblock, using a lot and often, covering up with clothing, staying out of the sun at peak mid-day hours will about cover it - but I am sure someone else has other ideas as well.

What are all you white guys talking about ?

Regarding the slathering: well moistured skin fares better in the sun than dry skin. My own personal experience shows that slathering to begin with, then small reapplications about every three hours works great.

My husband and I were at an all-day outdoor event this summer and never burned. We didn't realize it when we started, but our sunscreen was only SPF15 and had a 1999 expiration date. (We thought all Coppertone Sport was SPF30.) Keeping ourselves coated was the trick, I guess.

Repeated applications do have some value.

Several studies show that labels like "all day" or "water-resistant" are meaningless. There are no standards for those labels. You have to keep applying the stuff if it's going to be effective.

check out <http://www.aad.org/pamphlets/sunscreen.html>

Can anyone tell me what is the disadvantage of using a 45 spf sunscreen rather than a lower number?

So if I put on a 30, and then later put on a 15, does that mean I now have on a 45?

Sunscreen does expire. Throw out the old stuff.

1) 30 + 15 = 30.
Kind of like mixing 100 decibel music with 50 decibel music. The 50 doesn't add anything.

2) Only disadvantage to using 45 is they usually charge a little extra. Not much, but that's the only downside.

Lee, I've read 15 is the highest anyone needs, because anything above *that* isn't more effective. So go figure. Just make sure you use globs and reapply every couple of hours. The sunscreens are tested that way and that's how their effectiveness is rated. Have a great time!

As I said, where did you folks get your medical degrees? I don't think most of you know what you are talking about.
of course SPF 30 is better than 15, perhaps not 2 times as good, but certainly it offers more sun protection.