As the weather becomes warmer and we spend more days out in the open, it is paramount that we protect ourselves from the sun’s Ultraviolet (UV) rays. Although UV does provide us with health benefits such as vitamin D production, mood improvement, and increased energy, it is also the main culprit behind skin cancer. Research has shown that 1 out of 3 Americans reported getting sunburnt each year is due to this particular type of electromagnetic radiation and more than 400,000 cases of skin cancer, about 6,000 of which are melanomas (the deadliest form of skin cancer), are estimated to be related to indoor tanning. The two main types of UV light that pose a danger to us, UVA and UVB, are associated with skin aging and skin burning.
There are myriad ways to keep our skin safe e.g. wearing sun-safe clothing, hats, and eyewear or putting up UV window film on surfaces that let the sun in, but the most effective way to protect our skin is by using sunscreen. Sunscreen, including similar sprays, liquids, lotions, and powders, works by combining organic and inorganic active ingredients that block off the sun’s rays.
There are two types of sunscreen:
The first type is chemical sunscreen which contains organic carbon-based active ingredients designed to absorb UV radiation. In the process of catalysis, they transform UV rays into heat
which is then released from the skin. Manufacturers will typically use chemical UV filters such as Avobenzone, Octinoxate, Octisalate, etc. These sunscreen formulas are thinner and rub directly into the skin so leave less residue and are easier to spread. However, since it does not take effect immediately after application, it must be applied 20 mins prior to sun exposure and regularly afterward.
The second type is a physical sunscreen, also known as ‘mineral’ sunscreen, which works by reflecting, scattering, and blocking the UV light before it can penetrate the skin via active physical mineral blockers (most commonly Titanium Dioxide or Zinc Oxide) which are designed to adhere to the upper layer of the epidermis. These naturally offer broad-spectrum protection and are non-comedogenic, meaning they’re less inclined to block pores in the skin and cause oily skin. The benefit of choosing physical over chemical sunscreen is that it can protect against both UVA and UVB radiation whereas chemicals can only defend against one.
In order to know which sunscreen to choose, you must be familiar with the SPF (Sun Protection Factor) that determines the duration and effectiveness of the protection from the sunscreen. Your skin’s photosensitivity will affect the length of time that SPF can protect you from UV radiation with the tone of your skin being the deciding factor. (See the image below for guidance)
Elaine Lin
Bibliography
Colourscience. 2022. How Does Sunscreen Work to Protect Your Skin?. [online] Available at: https://www.colorescience.com/blogs/learn/how-does-sunscreen-work-to-protect-your-skin#:~:text=Chemical%20sunscreens%20contain%20organic%20compounds,against%20one%20or%20the%20other [Accessed 1 June 2022].
Cancer.org. 2022. Ultraviolet (UV) Radiation. [online] Available at: https://www.cancer.org/healthy/cancer-causes/radiation-exposure/uv-radiation.html#:~:text=UV%20rays%2C%20either%20from%20the,actinic%20keratosis%2C%20and%20solar%20elastosis [Accessed 1 June 2022].