Choosing the right sunscreen for your skin

How does sun’s ray actually damage our skin?

Sun produces 3 types of ultraviolet (UV) rays:

·         UVA (320 – 400nm wave length)
·         UVB (290 – 320nm wave length)
·         UVC (200 – 290nm wave length)

Penetrates deeper into the skin
Major contributor to skin damage, which leads to aging

Penetrates outer layer of the skin
Major contributor to sunburn

Almost completely absorbed by ozone layer
Does not affect the skin

What does SPF means?

SPF stands for Sun Protection Factor and refers to the theoretical amount of time you can stay in the sun without getting sunburned. For example, an SPF of 30 would allow you to stay in the sun 30 times longer than you could without sunscreen protection.

Product category
2 – 15
Minimal sun protection product
15 – 30
Moderate sun protection product
High sun protection product
30 - 100
Limited gain. No extra sun protection.

What are the differences between physical sunscreen and chemical sunscreen?
Basically sunscreen that provides board spectrum UVA protection can be divided into 2 types: physical sunscreen and chemical sunscreen.

Physical sunscreen
Chemical sunscreen
Protect the skin by deflecting the sun’s rays.
Protect the skin by absorbing the sun’s rays & transform it to harmless long wave radiation.
Physical agents:
Zinc oxide paste
Micronized zinc oxide
Titanium dioxide
Absorber agents:
Avobenzone(Parsol 1789)
Amino benzoic acid
Thick & opaque.
Colourless & odourless.
Should be applied 30 minutes before sun exposure.
Should be applied 30 minutes before sun exposure.
Comedogenicity: Titanium dioxide can be problematic for some people.
Comedogenicity: More irritation, some cause contact dermatitis.
Best to avoid those sunscreen that has PABA 5% as their ingredient.

A broad spectrum UVB sunscreen must have below mentioned ingredients:
-Salicylates (Octisalate, Homosalate)
-Cinnamates (Octyl methoxycinnamate)

FDA proposed a regulation on sunscreens on Dec 17, 2012, which stated that:

- Manufacturers cannot identify their products as “sunblocks”.

- Manufacturers cannot make claims that sunscreens are “waterproof” or “sweatproof”.

- Manufacturers cannot claim protection immediately on application (for example, “instant protection”) or protection for more than two hours.

- Sunscreen products that are not broad spectrum or that are broad spectrum with SPF values from 2 to 14 will be labeled with a warning that reads: “Skin Cancer/Skin Aging Alert:  Spending time in the sun increases your risk of skin cancer and early skin aging. This product has been shown only to help prevent sunburn, not skin cancer or early skin aging.” 

- Water resistance claims on the product's front label must state how much time a user can expect to get the declared SPF level of protection while swimming or sweating, based on standard testing. Only two time durations will be permitted on labels: 40 minutes or 80 minutes.

An interesting video on 'How the sun sees you'