As we know, the SPF number stands for how long a person wearing sun protection can stay in the sun before they start to burn. This length of time is determined by multiplying the SPF by 10 minutes. (for example: an SPF 15 x 10 minutes = 150 minutes a person can be in the sun before they start to burn). According to this calculation, an SPF of 50, 50 or even 70 should mean that a person can stay even longer in the sun without burning or re-applying. Yet this calculation can cause misunderstanding and misuse. According to a study by the FDA, an SPF 15 can provide approximately 93% protection from the sun, while an SPF 60 provides approximately 98%.
No matter which level of sunscreen is used, the guidelines for use and application are the same.
- Reapply every two hours
- Avoid the sun between 10am –2pm, when the rays are the strongest.
- Wear protective clothing, such as hats and cover-ups
As a guideline, appropriate SPF levels are:
- SPF 20 or lower – ideal for everyday use with minimal sun exposure, such as walking down the street or driving in a car to work
- SPF 30 or higher – ideal when spending 2 or more hours outdoors, even on a cloudy day, since clouds don’t block UV rays.
