To maintain good skin health, it’s essential that you wear sunscreen daily to protect yourself from harmful ultraviolet (UV) radiation, known as UVA and UVB. As well as burning your skin, UV rays can contribute to skin cancer and premature skin ageing.
What’s the difference between UVA and UVB radiation?
UVA rays have longer wavelengths and penetrate the skin more deeply than UVB rays. They are present throughout the day, regardless of the weather, whereas UBV rays are typically strongest between 10am and 4pm, and are more intense during the summer months.
UVA rays are also the primary cause of premature skin ageing as they damage collagen and elastin fibres in the skin, leading to lines, wrinkles and age spots. On the other hand, UVB rays are a major cause of sunburn. While UVA can penetrate glass and still contribute to ageing, UVB cannot so it’s unlikely you’ll burn through a window.
Both forms of UV contribute to an increased risk of skin cancers, so it’s essential to use sunscreen that protects against both.
How does sunscreen work?
There are two main types of sunscreens – physical and chemical. Both are effective against UVA and UVB rays but work in different ways.
Physical, also known as mineral, sunscreen contains ingredients that create a physical barrier on the skin that reflects and scatters UV radiation. The two most common mineral filters are zinc oxide and titanium dioxide. They provide immediate protection upon application.
Chemical sunscreen contains ingredients that absorb UV radiation, before releasing it harmlessly as heat. Common filters include compounds avobenzone, octocrylene, octinoxate and oxybenzone. They generally need some time to be absorbed, so take around 20-30 minutes to be effective upon sun exposure. Some individuals with sensitive skin might experience irritation or allergic reactions to certain chemical sunscreens.
What does SPF mean?
SPF stands for sun protection factor and indicates the level of protection the product offers against UVB radiation. The higher the SPF, the greater the protection.
Regardless of your level of SPF, it’s important to top up sunscreen every couple of hours, especially after sweating or swimming, to maintain its effectiveness.
How else can sun safety be maintained?
Staying out of the sun when it’s at its strongest is important, as is seeking shade whenever possible. Wearing a wide-brimmed hat and sunglasses can also help reduce your exposure to harmful rays.
Remember that UV radiation can be present on cloudy days and in winter months, so using sunscreen all year round will help maintain your skin health.