Yellow Stains from Anti-sweat and White Cast in Sunscreen

Here are the answers to your questions based on the information provided:

1. Regarding yellow stains from anti-sweat products:

   • Yes, it is true that anti-sweat ingredients, particularly aluminum compounds like Aluminum Chlorohydrate, can cause yellow stains on white clothes.
   • Aluminum Chlorohydrate is actually one of the aluminum compounds least likely to cause staining compared to others in the group.
   • The staining occurs when the product transfers to the fabric, especially when mixed with sweat.
   • To reduce the chance of staining, ensure the anti-sweat product dries completely on the skin before putting on clothes.
   • Heavy sweating can also contribute to the issue.

2. Regarding the white cast from your sunscreen formula:

   • The white cast is likely due to the high concentration (20%) of Zinc Oxide 200nm EasyDisperse™ in your formula.
   • This concentration is quite high and often used for strong protection needed in situations like going to the beach, rather than for daily use.
   • To fix the white cast while still avoiding chemical sunscreens as the primary active, you should reduce the concentration of Zinc Oxide 200nm.
   • You could consider supplementing with other types of sunscreen ingredients (some chemical ones are considered safe and can be used in smaller amounts) to maintain the desired SPF/PA level while reducing the Zinc Oxide concentration and minimizing the white cast. Zinc Oxide can still be the main active ingredient, but the overall formula might need adjustment beyond just reducing the ZnO percentage if you want to maintain high protection without the cast.