Determining SPF of Sunscreen Formula with Zinc Oxide and Titanium Dioxide
Question
Regarding the following sunscreen formula using [url=http://www.myskinrecipes.com/shop/spf-sunscreen/725-zinc-oxide-liquid-%E0%B8%8B%E0%B8%B4%E0%B8%87%E0%B8%84%E0%B9%8C-%E0%B8%AD%E0%B8%AD%E0%B8%81%E0%B9%84%E0%B8%8B%E0%B8%94%E0%B9%8C-%E0%B8%99%E0%B8%B2%E0%B9%82%E0%B8%99.html:3bqyubq1]Zinc Oxide 35nm Liquid[/url:3bqyubq1] / [url=http://www.myskinrecipes.com/shop/physical-sunscreen/724-titanium-dioxide-liquid-%E0%B8%97%E0%B8%B4%E0%B8%95%E0%B8%B2%E0%B9%80%E0%B8%99%E0%B8%B5%E0%B8%A2%E0%B8%A1-%E0%B9%84%E0%B8%94%E0%B8%AD%E0%B8%AD%E0%B8%81%E0%B9%84%E0%B8%8B%E0%B8%94%E0%B9%8C-%E0%B8%99%E0%B8%B2%E0%B9%82%E0%B8%99.html:3bqyubq1]Titanium Dioxide 15nm Liquid[/url:3bqyubq1] ([url=http://www.myskinrecipes.com/shop/emulsifier/666-water-capsule-water-in-oil-cream.html:3bqyubq1]Water-in-Oil Cream[/url:3bqyubq1]):
1.Water 44%
2.[url=http://www.myskinrecipes.com/shop/%E0%B8%8B%E0%B8%B4%E0%B8%A5%E0%B8%B4%E0%B9%82%E0%B8%84%E0%B8%99-silicone/171-cyclomethicone-cyclopentasiloxane-%E0%B9%84%E0%B8%8B%E0%B9%82%E0%B8%84%E0%B8%A5%E0%B9%80%E0%B8%A1%E0%B8%97%E0%B8%B4%E0%B9%82%E0%B8%84%E0%B8%99.html:3bqyubq1]Cyclomethicone[/url:3bqyubq1] 15%
3.[url=http://www.myskinrecipes.com/shop/physical-sunscreen/724-titanium-dioxide-liquid-%E0%B8%97%E0%B8%B4%E0%B8%95%E0%B8%B2%E0%B9%80%E0%B8%99%E0%B8%B5%E0%B8%A2%E0%B8%A1-%E0%B9%84%E0%B8%94%E0%B8%AD%E0%B8%AD%E0%B8%81%E0%B9%84%E0%B8%8B%E0%B8%94%E0%B9%8C-%E0%B8%99%E0%B8%B2%E0%B9%82%E0%B8%99.html:3bqyubq1]Titanium Dioxide 15nm Liquid[/url:3bqyubq1] 25%
4.[url=http://www.myskinrecipes.com/shop/spf-sunscreen/725-zinc-oxide-liquid-%E0%B8%8B%E0%B8%B4%E0%B8%87%E0%B8%84%E0%B9%8C-%E0%B8%AD%E0%B8%AD%E0%B8%81%E0%B9%84%E0%B8%8B%E0%B8%94%E0%B9%8C-%E0%B8%99%E0%B8%B2%E0%B9%82%E0%B8%99.html:3bqyubq1]Zinc Oxide 35nm Liquid[/url:3bqyubq1] 15%
5.[url=http://www.myskinrecipes.com/shop/%E0%B8%AA%E0%B8%B2%E0%B8%A3%E0%B8%81%E0%B8%B1%E0%B8%99%E0%B9%80%E0%B8%AA%E0%B8%B5%E0%B8%A2/1001-ethylhexylglycerin-caprylyl-glycol.html:3bqyubq1]Mild Preserved Eco[/url:3bqyubq1] 1%
What is the SPF of this formula?
Answer
Determining the exact SPF (Sun Protection Factor) of a sunscreen formulation requires specific laboratory testing, either in-vitro or in-vivo. It cannot be precisely calculated based solely on the list of ingredients and their percentages.
The final SPF is influenced by many factors, including:
- The specific type and quality of the active sunscreen ingredients (Zinc Oxide and Titanium Dioxide in this formula).
- The particle size and dispersion of these ingredients within the formulation.
- The overall formulation base and how it affects the film formed on the skin.
While Zinc Oxide and Titanium Dioxide are known effective physical sunscreen agents, the precise SPF of this specific formula would need to be determined through testing.
Therefore, I cannot provide an exact SPF value for the formula you provided.