There are two general types of sunscreens, physical and chemical ones. Physical sunscreens (mineral) use physical UV filters, while chemical sunscreens (on-mineral) use chemical UV filters. The debate between these sunscreens seems to provoke the most passion between the “play-it-safe” camp and those who believe concerns have been overly hyped, and that the benefits of using any sunscreen far outweigh the risk.
WHAT EXACTLY ARE CHEMICAL AND PHYSICAL SUNSCREENS?
Chemical sunscreens are ‘chemical absorbers’. They contain carbon compounds made in laboratory. Chemical sunscreens work by absorbing the sun’s rays and it vice versa in case of physical sunscreen. Physical sunscreens contain physical blockers like zinc oxide and titanium dioxide- natural minerals ground down to fine powders. They form a thin film on the skin and deflect or block sunrays/uv.
A BRIEF ON CHEMICAL SUNSCREEN:
- Chemical sunscreens go directly into the skin and they do take some time to be effective.
- When sunlight hits the skin, chemical absorbers absorb the active UV rays and release their energy in harmless ways.
- Avobenzone is one important ingredient used in chemical sunscreens which is a UVA chemical filter. The biggest drawback is that this chemical is unstable and is said to degrade in sunlight!
- Chemical sunscreens also tend to be more irritating to the skin, since multiple ingredients have to be combined to get broad spectrum coverage.
- Chemical sunscreens cannot protect burning of skin.
- These sunscreens are generally colourless, odourless and runny which most people would like.
- Some of the chemical sunscreens can actually cause free radical formation, which leads to more sun damage in the long run.
A BRIEF ON PHYSICAL SUNSCREEN:
- Physical sunscreens, use zinc oxide or titanium dioxide to help shield your skin from the sun. They form a layer on top of the skin and do not get absorbed into the skin at all.
- Physical sunscreens work immediately after application and you need not wait for it to be effective.
- They give UVB protection and prevent skin burning.
- Physical sunscreens containing zinc oxide are always preferred over titanium dioxide for 2 reasons- it provides protection against the entire spectrum of UVA and UVB rays and is great for sensitive skin.
- One major downside to physical sunscreens is that they tend to be chalky and thick.
- All the ingredients in physical sunscreen are stable unlike the one in chemical sunscreen.
- Titanium dioxide can be problematic for some people (cause acne) but zinc oxide are completely safe.
- Physical sunscreens do not cause free radicals like chemical sunscreens.
CONCLUSION:
Because chemical sunscreens are resistant to sweat and water (unlike physical sunscreens) they are best for a day of swimming, or the beach or sweaty sportsy playing. But, since the sun can break down their effectiveness (some up to 90% in one hour!) you MUST re-apply often. Physical sunscreens however are best for everyday use since they last long and need not be reapplied every 2 hours. Choose a physical sunscreen containing zinc oxide for everyday use that can protect your skin from both UVA and UVB rays!