Sun Protection Factor SPF

What is SPF?

SPF (Sun Protection Factor) is a measure of how well a sunscreen protects your skin from UVB rays, which are the primary cause of sunburn and can contribute to skin cancer. SPF indicates how long a person can stay in the sun without getting burned compared to how long they can stay without protection. For example:

• SPF 15 means you can stay in the sun 15 times longer than if you were unprotected.
• SPF 30 provides roughly double the protection of SPF 15.

However, SPF ratings mainly cover protection from UVB rays, not UVA rays, which also contribute to skin damage and aging.

Understanding SPF Formulation

A common formulation with SPF is sunscreen. Let's look at a general SPF 30 sunscreen formulation:

Example Formulation of an SPF 30 Sunscreen:

• Active Ingredients:

  • Avobenzone (3%): A chemical filter that protects primarily against UVA rays.
  • Homosalate (10%): Absorbs UVB rays.
  • Octisalate (5%): Helps absorb UVB rays.
  • Octocrylene (10%): Absorbs UVB and some UVA rays while stabilizing Avobenzone.
  • Zinc Oxide (7%): A physical blocker that provides broad-spectrum protection by reflecting UVA and UVB rays.

• Inactive Ingredients:

  • Water: Acts as a solvent and carrier for other ingredients.
  • Glycerin: Provides moisture to the skin.
  • Dimethicone: Acts as a skin conditioning agent and gives the sunscreen a smooth texture.
  • Cetearyl Alcohol: A fatty alcohol that stabilizes and thickens the formula.
  • Sorbitan Olivate: A natural emulsifier derived from olives to help combine oil and water in the formula.

Explanation of SPF 30 Protection:

• SPF 30 means the sunscreen blocks approximately 97% of UVB rays.
• It’s crucial to reapply every 2 hours, as sweat, water, and prolonged sun exposure can reduce its effectiveness.

Would you like details on other types of SPF products, such as moisturizers or makeup with SPF?