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)
UVA
Penetrates deeper into the skin
Major contributor to skin damage, which
leads to aging
UVB
Penetrates outer layer of the skin
Major contributor to sunburn
UVC
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.
SPF
|
Product
category
|
2 – 15
|
Minimal sun protection product
|
15 – 30
|
Moderate sun protection product
|
>30
|
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
Ecamsule(Mexoryl)
|
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'
