Choosing suitable and safe Sunscreen / Sunblock Creams.

We need sun, but too much may cause sunburns,

accelerates aging, and causes skin cancer.

The best way to prevent from sun burn is cover-up and looking for shade!

Taking care of our skin from excessive sun exposure,

Follow the application instruction dose of the products precisely, don’t reduce it !

The best way to prevent from sun burn is cover up and looking for shade, especially during peak sunlight hours, between 10 a.m until 4 p.m. But as a matter of fact, there is no arguing about the fact that sunscreen creams / sunblock creams prevent painful sunburns, and they reduce the visible sign of aging, the best protection is achieved by application 15–30 minutes before exposure, followed by reapplication 15–30 minutes after the sun exposure begins.

Ultraviolet rays:

Infrared rays: wavelength: >780 nm.

Sunlight rays: wavelength: 400 – 780 nm.

Ultraviolet rays: wavelength: 100 – 400 nm.

X-rays: wavelength: <>

Ultraviolet rays (UV) exposure can be very harmful, or harmless, depending on

1. the type of UV,
2. the type of exposure,
3. the duration of exposure, and
4. the individual differences in response to UV.

The UV region of the electromagnetic spectrum encompasses a range from 400 nm (nanometers) through 100 nm, and is further sub-divided into four smaller regions:

1. UV-A (315 to 400 nm): Long wave UV, also known as "black light ", the major type of UV in sunlight, responsible for skin tanning, generally not harmful, used in medicine to treat certain skin disorders.
2. UV-B (280 to 315 nm): Medium-wave UV, a small, but dangerous part of sunlight. Most solar UV-B is absorbed by the diminishing atmospheric ozone layer. Prolonged exposure is responsible for some type of skin cancer, skin aging, and cataracts (clouding of the lens of the eye).
3. UV-C (200 to 280 nm): Also known as "shortwave" UV, includes germicidal (253.7nm wavelength) UV used for air disinfection. Unintentional overexposure causes transient redness and eye irritation, but does NOT cause skin cancer or cataracts.
4. Vacuum UV (100 to 200 nm)

Ultraviolet-B rays (UVB rays) causes sunburn and skin cancer, ultraviolet-A rays are more plentiful than UVB rays, also less carcinogenic, nevertheless, good sunscreen cream products should protect skin against both types of ultraviolet rays (UVA-UVB rays), since both can contribute to skin cancer and photo-aging, usually sunscreen cream products that protect both ultraviolet rays are labeled broad-spectrum.

It should be noted that

relating to the application of sunscreen creams, we have to follow the application instructions precisely, don’t reduce its dose!

What is Sun protection factor (SPF)?

The SPF of a sunscreen is a laboratory measure of the effectiveness the protection of sunscreen against UV-B, the ultraviolet radiation that causes sunburn, the SPF indicates the time a person with sunscreen applied can be exposed to sunlight before getting sunburn compare to the time a person without sunscreen, someone who would burn after 12 minutes in the sun would expect to burn after 120 minutes when protected by / uses a sunscreen with SPF 10.

Type of Sunscreen / Sunblock Cream

[1]. Mineral Sunblock creams (Mineral blocks):

TiO₂ & ZnO

Unlike Chemical sunscreen creams which prevent sun burn by absorbing the sun’s rays, the mineral sunscreen cream will block the sun rays. Mineral based sunscreen creams form protective physical barrier on the skin that deflects both Ultraviolet-A (UVA) and Ultraviolet-B (UVB) rays.

The most commonly used minerals for sunscreen (Sunblock) cream are Titanium dioxide (TiO₂) and Zinc oxide (ZnO). The different of the mineral based sunscreen and the chemical based sunscreen is the usage of the mineral based sunscreen will left a thin opaque white mark layer on the skin. In order to make Titanium dioxide and Zinc oxide sunscreen transparent, the manufacturers using smaller particles of the mineral ingredients, by micronization process to reduce the particle size, which is called nanoparticles (nanometer particles), nanoparticles are mineral particles that have been fragmented to size below 100 nanometers, the micronization process itself is called nanotechnology, nanoparticle mineral sunscreen cream when applied to the skin are less visible. It should be noted that, the term micronized (makes micron particles) does not always contains nanoparticles, the size of 1 micron (μm) particles equal with one millionth of a meter, while 1000 nanometer (nm) particles equal with 1 micron particles, so 1 nanometer particle equal with one billionth of a meter (m).

The so-called nanoparticles are of most concern, it is unclear whether or not they are being absorbed through the skin, nano-particles have a greater potential to penetrate the skin dermis into the bloodstream, the consequences of which are unknown.

If we do not convince, the safety way we can take is avoiding mineral sunscreen products containing nanoparticles, caution also should be made to avoid applying nanoparticles sunscreen cream to cuts, wounds and abrasions (damage areas of the skin)!!!

Maximum concentration used:

1. Titanium dioxide (TiO₂): 25 % and no limit in Japan,
   
2. Zinc oxide (ZnO): 25 % in USA, 20 % in Australia, 25 % in EU particle size >100 nm, no limit in Japan.

[2]. Chemical Sunscreen creams (Chemical blocks):

The Chemical Sunscreen creams allow the sun’s rays to penetrate the skin, and the active ingredients the synthetic chemical compounds absorb the radiation of ultraviolet rays (UVA & UVB), prevent it from burning or damaging the skin.

Avobenzone / Butyl-Methoxydibenzoylmethane

Avobenzone is oil soluble, is one of the most common UVA-protective active ingredients used in Sunscreen cream, it absorbs the full spectrum of UVA rays, absorbs ultraviolet light over a wider range of wavelengths than many other organic chemical sunscreen agents used in many commercial preparations marketed as broad spectrum sunscreens creams, it has an absorption maximum of 357 nm, frankly speaking, the protection activity of Avobenzone is unclear, if it is not stabilized with photostabilizer, Avobenzone has a tendency to break down under sunlight, causes not effective anymore, Maximum concentration used: 3 % in USA, 5 % in European Union Countries (EC), 10 % in Japan.

Benzophenon (Diphenylmethanon)

Benzophenon may cause irritation and rashes in many users, and moreover, Benzophenon appears to mimic the hormone estrogen in the body, that means Benzophenon behaves like estrogen hormone, this chemical sunscreen may disrupt user’s endocrine system, as Benzophenon more readily to be absorbed by the skin compares to other sunscreen ingredients, the use of Benzophenon in sunscreen cream products is particularly concerning.

Maximum concentration used:

Ecamsule / Terephthalylidene Dicamphor Sulfonic Acid.

Similar to Avobenzone Ecamsule is a UVA-protective sunscreen active ingredient, filter out UVA rays to prevent UV-related signs of aging, it is known for its excellent photostability, Ecamsule was approved by the FDA in 2006, Maximum contration used: 10 %

Padimate-O / Octyldimethyl-PABA

Padimate-O is derivative of PABA / para-aminobenzoic-acid ( PABA is also a standard ingredient in sunscreen product for years, but recently most of the manufacturers remove it from sunscreen cream formula, because PABA stains clothing and causes allergies in many users).

Padimate-O used in sunscreen cream formulations because it can effectively protect the skin from untraviolet-B rays (UVB_rays), which are known to cause sunburn and skin cancer, Padimate-O preventing direct DNA damage by UVB rays.

Maximum concentration used: 8 % in USA, Australia, and EC (maybe delisted), 10 % in Japan.

Other FDA approved UV-filter chemical sunscreen ingredients:

• p-Aminobenzoic acid (PABA)
• Cinoxate (2-Ethoxyethyl p-methoxycinnamate).
• Dioxybenzone (Benzophenone-8).
• Homosalate (Homomethyl salicylate), The salicylic acid portion of the molecule absorbs ultraviolet rays, protecting the skin from sunburn, sun damage. Maximum concentration used: 15 % in USA and Australia, 10 % in EC and Japan, 15 % in USA and Australia.
• Methyl anthranilate (Methyl-aminobenzoate).
• Octocrylene (3-diphenyl acrylic acid).
• Octyl-methoxycinnamate / 2-ethylhexyl-paramethoxycinnamate, Its primary use is in sunscreens and other cosmetics to absorb UV-B rays from the sun, protecting the skin from damage, Maximum concentration used: 7.5 % in USA, 10 % in EU and Australia, 20 % in Japan.
• Octyl salicylate (2-Ethylhexyl salicylate).
• Oxybenzone (Benzophenone-3).
• Phenylbenzimidazole sulfonic acid.
• Sulisobenzone (2-Hydroxy-4-Methoxybenzophenone-5-sulfonic acid).
• Trolamine salicylate (Triethanolamine salicylate).