There are a lot of factors that influence tanning. For example, if you are not wearing any sunscreen with PSF, you may tan in 10-15 minutes. SPF stands for sun protection factor. It’s the measure of how much UV gets through the screen. The higher the number, the less UV passes through.https://www.businessinsider.com.au/how-does-sunscreen-work-2018-1. An SPF of 30 allows one-thirtieth or 3.3% of UV to reach your skin. This means it filters 96.7% of UV. With an SPF of 50, 98% is filtered and one-fiftieth or 2% gets through. So while the difference between SPF 30 and SPF 50 sounds like a lot – it is a pretty modest (only 1.3%) – difference in protection.
So if your unprotected skin would take ten minutes to show signs of burning, then properly applying SPF 30 sunscreen would slow the rate of burning to the point where it would take 30 times longer, or 300 minutes in total. SPF 15 would take 150 minutes, while SPF 50, 500 minutes.
According to the Australian Cancer Council, there are also many myths about sun protection, https://www.cancer.org.au/cancer-information/causes-and-prevention/sun-safety/10-myths-about-sun-protection, here are the most important ones.
- Sun damage is not possible on windy, cloudy or cool days. (FALSE!)
- A fake tan darkens the skin, protecting the skin from the sun. (FALSE!)
- People with olive skin are also at risk of skin cancer. (FALSE!)
- Sunscreen is not necessary when using cosmetics with SPF. (FALSE!)
- People with olive skin are not at risk of skin cancer. (FALSE!)
- You can stay out longer in the sun when you are wearing SPF50+ than you can with SPF30 (FALSE! Remember the pretty modest difference, we mentioned above.)
- Plenty of sun exposure is required to avoid vitamin D deficiency.
- You can’t get burnt in the car through a window.