Sunscreen vs sunblock: What's the difference?

What is the difference between sunscreen and sunblock?

The meaningful formula distinction is between chemical, mineral and hybrid sunscreens. All three absorb the sun's rays; mineral sunscreens also reflect them. "Sunblock" is not a protection rating, despite sounding like sunscreen has been promoted.12

Which sunscreen should you choose?

Choose a broad spectrum, water resistant sunscreen with SPF 30 or higher. Broad spectrum means protection against both UVA and UVB: UVA contributes to premature aging, while UVB is the main cause of sunburn. Both can contribute to skin cancer. In the UK, look for SPF 30 or higher and at least four star UVA protection; a UVA circle indicates that the product meets the EU standard.23

Creams suit dry skin and facial use; gels suit oily skin and hairy areas; sticks are useful around the eyes. Pick a sunscreen you will use repeatedly, because a bottle left in a cupboard has chosen an indoor lifestyle.2

If visible light worsens dark spots, especially on darker skin tones, consider a tinted sunscreen containing iron oxides. These add visible light protection; iron oxides appear under inactive ingredients. Choose a shade that matches your skin tone and undertone. Tinted options can reduce visible white residue, which is not a compulsory uniform for sun protection.24

How should you apply either type?

1. 1Apply sunscreen every day you will be outside, including cloudy days. Follow the bottle's directions. For prolonged sun exposure, NHS guidance advises applying it 30 minutes before going out and again just before leaving.
2. 2Cover all exposed skin, including your face, neck, ears, hands, feet and exposed scalp. NHS guidance suggests around six to eight teaspoons for an adult's entire body. Applying too thinly reduces protection.
3. 3Reapply every two hours outdoors, and straight after swimming, towel drying or sweating, or when sunscreen has rubbed off.
4. 4Add shade, protective clothing, a hat and sunglasses. Sunscreen alone cannot fully protect you.

Water resistant does not mean waterproof. A label stating 40 or 80 minutes describes how long the labelled SPF protection lasts during swimming or sweating, not permission to skip reapplication afterward.1

How do sunscreen and sunblock compare for tanning?

Neither name makes tanning safe or promises that tanning cannot happen. UV tanning is a response to skin damage: the skin produces more melanin, the pigment that darkens it. A base tan does not prevent sunburn. If you want a tanned appearance, sunless tanning avoids UV tanning exposure, but the resulting colour does not protect you from UV rays.36

SPF compares sunburn protection, not safe hours outdoors. Higher SPF increases sunburn protection, but sun intensity, the amount applied and reapplication affect actual exposure. Do not calculate your time in the sun by multiplying your usual burning time by the SPF number.7

Who needs extra care?

Some medicines increase sun sensitivity, including certain antibiotics and diuretics. Ask your healthcare professional about sun precautions if you take medication. Keep babies younger than six months out of direct sunlight and ask a healthcare professional before applying sunscreen. If sunburn develops, stay out of the sun until it heals; seek medical help for severe swelling, blistering or feeling unwell.135