How effective is sun block?

How effective is sun block?

Sun block is an important part of our armamentarium to protect ourselves from ultraviolet damage and prevent skin cancer. It's extraordinarily important to note, however, that sunblock is the third thing that's important in protecting ourselves against skin cancer. The most important one is behaviour. The second most important one would be clothing. Where behaviour and clothing doesn't work, sunblock has a role. Trying to ask sunblock to protect ourselves from the sun is like asking an umbrella to protect yourself in a hurricane. It can't do it, particularly if you're out getting sun.