SPF, UVA, UVB & PA Ratings Explained: The Complete Sunscreen Guide

Sunscreen 101

I scream, you scream and we all SHOULD scream for “Sunscreen”

Basics:

• SPF is sun protection factor, it measures protection against UVB rays. SPF 30 blocks approx. 97% of UVb whereas SPF 50 blocks approx. 98%.

• PA factor is Japanese-Korean rating that measures how well a sunscreen protects against UVA rays. PA ++++ offers very  high UVA protection and it would take 16 times more UVA exposure to darken the skin.

• Broad spectrum offers protection against both UVA and UVB rays

• Water resistance - remains effective for about 40-60mins only, while swimming or sweating. 

Types:

• Chemical: contains Oxybenzone, Avobenzone, Octinoxate, etc. it works by absorbing UV rays and converting it into heat. It can irritate sensitive skin and the ingredients may affect marine life.

• Mineral/physical: contains Zinc oxide, Titanium dioxide as its main ingredients. It sits on the skin surface and reflects UV rays, hence offers immediate protection. Works well for sensitive and post procedure skin.

• MIxed: it combines both physical and chemical filters to offer broad spectrum protection. By adding chemical filters to physical sunscreen it makes it mor4 cosmetically elegant.

Why do we need sunscreen?

• Preventing skin cancer is the first and most important reason to wear sunscreen. Although skin cancers constitute only about 1-2% of all diagnosed cancers in India, the incidence rates are on a rise due to increased UV exposure, changing lifestyle and urbanisation.

• Prevents sunburn (from UVB) and skin damage.

• Prevents premature aging.

• Protects against hyperpigmentation. 

• Reduces inflammation, for people with rosacea or lupus.

Who needs sunscreen?

Unless you are an infant (<1yr), you definitely need to be applying and reapplying your sunscreen. If your infant is getting too much sun, like on a vacation you can apply mineral sunscreen, or else stick to protective clothing and shade. People of all ages and skin tones need to use sunscreen regularly. Melanin in the skin offers some natural protection but not enough to prevent damage, hence with the changing environment and rise in urbanisation its important to use sunscreen regularly to protect your skin. Consistency in key with this particular step of your skincare routine.

How to apply?

Apply sunscreen 15-30mins before sun exposure. Reapply every 2hrs if you are outdoors, immediately  after swimming and excessive sweating. If you are completely indoors all day, reapplying adequate quantities twice a day is sufficient.

Do’s:

• Use SPF 30 or higher with broad spectrum

• Apply adequate quantity - 2 finger lengths of product (index+middle) for face or ¼ teaspoon for face and 1 shot glass full evenly divided for body

• If the required quantity seems like too much- you can apply in layers

• Do not forget eyelids, lips, back of hand, hairline, scalp (for those who are bald), ears, neck and back of ears

• Apply 15-30mins before sun exposure

• Reapply every 2hrs or immediately after swimming or excessive sweating

• Use daily- even when indoors or cloudy

• Check expiration date and other instructions on the sunscreen container

Don’ts:

• Don't rely on the sunscreen present in makeup

• Don't forget SPF lip balm

• Don’t use body sunscreen on face- can cause irritation or breakouts

• Don’t assume water-resistant means waterproof, you still have to reapply

• Don’t use spray sunscreen for face, inhaling the particles is harmful

Tips & tricks:

• Layer your sunscreen to get the best protection

• Spray is convenient for body not face, rub evenly

• Mixing sunscreen with makeup or moisturiser dilutes the protection

• Mineral sunscreens are great for sensitive skin and for post-procedure care

• Powder sunscreens are good for touch-ups over makeup, but not on its own

• Stick sunscreens are good fro on the go reapplication

• There are sunscreen specifically made for those with acne prone skin, pigment prone skin, melasma prone skin - choose wisely

Are sunscreens harmful?

NO, for most people. In very few it can cause certain issues:

• Skin irritation or allergies- fragrance, preservatives, chemical filters.

• Hormone disruption - oxybenzone - has a hormone-like effect. But it is only tested in labs on animals and can cause so theoretically, Human data is inconclusive.

• Environmental impact- Oxybenzone and octinoxate may harm coral reefs.

The solution to all the above problems would be to shift to mineral sunscreens.