What SPF really means and how much you should be using

Sunscreen is one of the most effective preventative products in the pharmacy, but it is often under-applied.

What the numbers mean

SPF measures protection against UVB, the wavelength that causes burning. Look for broad-spectrum UVA and UVB protection.

How much to use

• Use a generous teaspoon for the face and neck.
• Use roughly two tablespoons for the whole body.
• Reapply every two hours and after swimming, towel-drying or heavy sweating.

SPF is not a measure of how long you can stay out. Protection drops as sunscreen is rubbed, sweated or washed off.

Cloud still counts

UV levels in Ireland can be high enough to cause damage from April to September, including on overcast days.