While SPF 90 sunscreen is not inherently unsafe for the face, it's not the most beneficial choice. Experts recommend using an SPF between 15 and 50.
Understanding SPF and Sun Protection
Sun Protection Factor (SPF) measures how well a sunscreen protects skin from UVB rays, the kind that cause sunburn. However, higher SPF numbers do not translate to a proportionally higher level of protection.
- SPF 15: Blocks about 93% of UVB rays.
- SPF 30: Blocks about 97% of UVB rays.
- SPF 50: Blocks about 98% of UVB rays.
As you can see, the increase in protection diminishes at higher SPF values.
Why SPF 90 Isn't Ideal
According to experts, sunscreens with an SPF higher than 50 aren't worth buying because they provide only marginally better protection than SPF 50. A very high SPF might encourage you to spend more time in the sun, which can be harmful.
The reference states that you should choose an SPF between 15 and 50 and apply liberally and reapply often.
Potential Issues with High SPF
- False Sense of Security: SPF 90 might make you feel overly protected, leading to less frequent reapplication or prolonged sun exposure.
- Minimal Additional Benefit: The increase in protection from SPF 50 to SPF 90 is very small.
- Chemical Overload: Higher SPF sunscreens may have a higher concentration of chemical UV filters, which could potentially irritate sensitive skin.
What to Do Instead
- Choose an SPF between 15 and 50: This range offers adequate protection for most people.
- Apply liberally: Use about a shot glass full for your body and a good amount for the face.
- Reapply frequently: Do it at least every two hours, or after swimming or sweating.
- Seek shade: Combine sunscreen use with protective clothing and seeking shade during peak sun hours.
| SPF Level | UVB Protection |
|---|---|
| 15 | About 93% |
| 30 | About 97% |
| 50 | About 98% |
| 90 | Marginally better than SPF 50 |
In summary, while SPF 90 is not unsafe, it is not necessary. The best strategy for sun safety involves using an SPF between 15 and 50, applying it generously, and reapplying often, along with other sun protection measures.
