Today I saw a commercial on tv where they set up an “interview” with a person to show that their product is good. The girl was telling she uses sunscreen every day and reapplies it every 30 minutes. This is stupid and unnecessary. I was wondering : how much sunscreen do you have tu wear to get poisoned?
The chemicals in sunscreen get used up/wear out. 30 minutes is a bit much unless you sweat like crazy. 2 hours is the usual interval recommended.
The webmd website only lists ingestion under the overdose section. You can have allergic reactions and interactions with other drugs are possible, but apparently just slathering on too much isn’t a concern. Ingredients in sunscreen vary, and some can cause skin irritation.
It also notes that once you get to SPF30, anything greater doesn’t provide much additional benefit.
They recommend applying 30 minutes before exposure to sun and the reapplication interval listed is 2 hours, the same as what runner pat posted.