Does Sunscreen Expire? Experts Share Signs of Spoiled SPF
He continues, “The ingredients in chemical sunscreen, such as oxybenzone, avobenzone, and homosalate are more prone to oxidation [in sunlight], making them less effective over time.” On the other hand, “mineral agents, such as zinc oxide, titanium dioxide, and iron oxide, are inert and much slower to break down [under heat or direct sunlight]”—either on … Read more