What Does SPF Mean?

SPF is short for sun protection factor. The higher the number that follows it, such as SPF 30 or SPF 50, the more time you may be able to spend in the sun without getting sunburnt from its ultraviolet B (UVB) rays.

Your skin needs protection against two types of UV rays: ultraviolet A (UVA) rays and ultraviolet B (UVB) rays. If a product can protect you from both, it's called broad-spectrum UV protection.

How SPF Works

Simply put, the number after SPF indicates how much longer it may take for you to get sunburnt after you've applied SPF, compared to when you're not using any SPF at all.

For example, if you usually start to get sunburnt after about 10 minutes without any sun protection, putting on an SPF 30 moisturiser means you can spend approximately 5 hours in the sun without the risk of sunburn because 10 x 30 equals 300 minutes. Keep in mind, this calculation is just an estimate, because your risk of sunburn depends on many factors like weather, season and time of day.

The higher the SPF number, the better your protection against sunburn. The minimum recommended for daily use is 15, and it should provide UVA protection as well.

Understanding UVA and UVB Rays

The sun is responsible for up to 80 percent of the signs of premature skin ageing. There's an easy way to remember the difference between UVA and UVB rays:

• UVA ending with A is for ageing: UVA rays can penetrate through clouds and even glass windows, so your skin needs protection even if it's raining or you're indoors. They get deep into your skin's surface and over time can cause visible skin ageing like fine lines and wrinkles.
• UVB ending with B is for burning: Our exposure to UVB rays varies by time, season and location. They cause more skin damage at higher altitudes because the atmosphere is thinner and can't filter as many UVB rays.

Both UVA and UVB rays are invisible and we are exposed to them all year round. UV rays are also one of the main causes of skin cancer, so protection against both is key for preserving your skin's youthful look and protecting your health.

SPF Effectiveness

The SPF number on a product label indicates how much UVB ray protection you receive:

• SPF 15 fends off 93% of UVB rays
• SPF 30 fends off 97% of UVB rays
• SPF 50 fends off 98% of UVB rays

When you choose your SPF face cream, always go for products with broad-spectrum UV protection, because it gives you protection against both UVA and UVB rays.

Why Use an SPF Moisturiser?

Many SPF moisturisers feel heavy, sticky and greasy on the skin. However, an SPF moisturiser is a true multitasker that fits right into your existing skincare routine. It comes at the same step as a regular moisturiser would – right after you've cleansed your face and applied any serum you're using.

Apply the moisturiser with SPF liberally. Don't forget the hairline, neck and décolletage to make sure all exposed areas get coverage. A moisturiser with SPF can kill two birds with one stone, streamlining your morning routine while you leave home knowing you're taking great care of both how your skin looks and its health.

The Bottom Line on SPF

Sun protection helps protect your skin against invisible yet harmful UVA and UVB rays that are responsible for burning your skin and up to 80 percent of the signs of premature skin ageing. Don't forget to apply SPF every day, no matter the weather, as UVA rays can penetrate overcast conditions too. Always follow the instructions on the pack or bottle about how often you should reapply.