Sunscreen is a topical product that absorbs or reflects ultraviolet (UV) radiation from the sun. It is used to protect the skin from sunburn, premature skin aging, and skin cancer. Sunscreen is available in a variety of forms, including lotions, creams, sprays, gels, and sticks.
There are two main types of sunscreens: mineral and chemical.
- Mineral sunscreen: Also known as physical sunscreen, mineral sunscreen contains active ingredients such as zinc oxide and titanium dioxide. These minerals work by sitting on top of the skin and reflecting UV radiation, preventing it from penetrating the skin. Mineral sunscreens offer broad-spectrum protection, blocking both UVA and UVB rays. They are generally considered safer for sensitive skin and have less potential to cause irritation or allergic reactions.
- Chemical sunscreen: Chemical sunscreens contain organic compounds, such as avobenzone, oxybenzone, and octinoxate, which absorb UV radiation and convert it into heat, which is then released from the skin. Chemical sunscreens can offer broad-spectrum protection, depending on the combination of active ingredients used. However, some chemical sunscreens may cause irritation, and certain ingredients have raised concerns regarding environmental impact and potential hormone disruption.
After a facial or treatment procedure on the face, it is advisable to use a mineral sunscreen containing zinc oxide. This is because chemical sunscreens are absorbed into the skin and can expose the treated, irritated skin to additional chemicals. In contrast, zinc oxide does not get absorbed and provides anti-irritation and anti-inflammatory benefits to the skin.
The sun emits two types of UV radiation: UVA and UVB. UVA rays cause premature skin aging, such as wrinkles and age spots. UVB rays cause sunburn and skin cancer. Sunscreen should provide broad-spectrum protection, which means that it protects against both UVA and UVB rays.
The sun protection factor (SPF) of a sunscreen indicates how well it protects against sunburn. An SPF of 15 blocks about 93% of UVB rays, an SPF of 30 blocks about 97% of UVB rays, and an SPF of 50 blocks about 98% of UVB rays. The higher the SPF, the more protection the sunscreen provides.
Sunscreen should be applied to all exposed skin 15 minutes before going outside. It should be reapplied every two hours or more often if swimming or sweating. Sunscreen should also be applied to the lips, ears, and the backs of the hands.
Here are the characteristics of UVA and UVB, the two main types of UV rays:
- UVA rays: These have the longest wavelength (320-400 nanometers), penetrating deep into the dermis, which is the skin’s thickest layer. Prolonged exposure to UVA rays can lead to premature skin aging, wrinkling (photoaging), and suppression of the immune system. UVA rays can penetrate glass and clouds, so they can affect your skin even when you’re indoors or on a cloudy day.
- UVB rays: These have a medium wavelength (280-320 nanometers) and are primarily responsible for direct damage to the skin’s more superficial epidermal layers. UVB radiation plays a key role in skin reddening and sunburn, and it significantly enhances the development of skin cancer. Unlike UVA rays, the intensity of UVB rays vary by season, location, and time of day, with peak hours being between 10 a.m. and 4 p.m.
Proper application and usage of sunscreen are crucial, as incorrect use can lead to a false sense of protection for clients, causing them to expose their skin to the sun and incur greater damage than if they had not worn any sunscreen at all. The amount of sunscreen used is also vital, ensuring that it fully covers the skin’s surface. For instance, when applying sunscreen to the face, it should also cover the ears, neck, and décolleté.
Here is some more recommendations of how to use sunscreen:
- Recommend an SPF of 30 or higher.
- Apply sunscreen to all exposed skin, including the face, ears, neck, and backs of the hands.
- Reapply sunscreen every two hours, or more often if swimming or sweating.
- Choose a sunscreen that is water-resistant.
- Use a sunscreen that is fragrance-free and non-comedogenic (won’t clog pores).