Daily News Analysis ‘Sun Protection Factor (SPF) ’ : 5 June

Why in News: 

• Increased public awareness campaigns during summer have highlighted the importance of understanding Sun Protection Factor (SPF) and sunscreen use.

Key Facts: Meaning and Significance of SPF

• SPF (Sun Protection Factor) measures a sunscreen’s ability to protect the skin from UVB (Ultraviolet B) radiation.
• UVB rays are primarily responsible for sunburn (erythema) and skin damage.
• SPF indicates how much longer protected skin can resist UVB-induced redness compared to unprotected skin under standard conditions.

SPF Ratings and Protection

• SPF 30: Blocks about 95–97% of UVB rays.
• SPF 50: Blocks about 97–98% of UVB rays.
• SPF 80: Blocks nearly 99% of UVB rays.
• Protection increases only marginally at higher SPF values; no sunscreen blocks 100% of UV radiation.

SPF Limitations

• SPF measures protection only against UVB rays, not UVA (Ultraviolet A) rays.
• UVA rays penetrate deeper into the skin and are associated with:
  • Pigmentation
  • Premature ageing (photoageing)
  • Wrinkles
  • Loss of skin elasticity