While SPF 70 offers slightly more protection than lower SPFs, it's arguably not necessary for most people and daily use. The incremental benefit is minimal.
Understanding SPF and UVB Protection
Sun Protection Factor (SPF) indicates how well a sunscreen protects you from UVB rays, the kind of radiation that causes sunburn and contributes to skin cancer.
- A higher SPF number means more protection, but the differences become smaller at higher SPFs.
The Marginal Benefit of SPF 70
According to the Skin Cancer Foundation and available research, SPF 70 blocks only about 0.6% more UVB rays compared to SPF 50.
| SPF | UVB Rays Blocked |
|---|---|
| SPF 30 | ~97% |
| SPF 50 | ~98% |
| SPF 70 | ~98.6% |
Daily Use Recommendations
- For daily use, the Skin Cancer Foundation recommends a broad-spectrum sunscreen with an SPF of at least 30.
- Proper and frequent application is more important than a super-high SPF.
Practical Considerations
While SPF 70 isn't necessarily harmful, consider the following:
- Cost: Higher SPF sunscreens may be more expensive.
- Application: People often don't apply enough sunscreen. Focusing on generous and frequent application of an SPF 30 or 50 may be more effective than sparsely applying a higher SPF.
- Broad-spectrum protection: Ensure your sunscreen protects against both UVA and UVB rays.
