Regarding SPF 100 Claims

Based on the information provided, claiming SPF 100 on a product is often considered an exaggeration or marketing tactic rather than a reflection of significantly increased protection compared to lower SPF values like 50+.

Here's why:

• Marginal Benefit: SPF primarily measures protection against UVB rays. While SPF 100 technically blocks slightly more UVB than SPF 50, the difference is minimal (e.g., SPF 50 blocks ~98%, SPF 100 blocks slightly more). The increase in protection percentage is very small beyond SPF 30 or 50.
• UVA Protection is Key: SPF doesn't fully represent protection against UVA rays, which are crucial for preventing skin aging and cancer. A high SPF doesn't guarantee adequate UVA protection.
• Regulatory Limits: Many regulatory bodies, such as the EU Cosmetic Commission and potentially the Thai FDA (อย.), limit the maximum allowed SPF claim on product labels to 50+. This is because higher numbers can be misleading to consumers, suggesting a level of protection that isn't significantly different from 50+ and might lead to misuse (applying too little, staying in the sun too long).

Therefore, claiming SPF 100 is likely viewed critically by regulatory bodies like the Thai FDA (อย.) and may not be permitted, requiring the product to be labeled as SPF 50+ instead. It's more important for a sunscreen to offer broad-spectrum protection (both UVA and UVB) and for the user to apply a sufficient amount.