What are the three bad ingredients in sunscreen?

The UV filters most commonly discussed as concerning are oxybenzone (linked to reef damage and questioned for hormonal effects), octinoxate (also associated with reef damage), and homosalate at high concentrations (under review by European regulators). These concerns are primarily environmental or based on high-dose studies rather than typical use. Many sunscreens are now formulated without them.

It is worth noting that bad is context-dependent here. Oxybenzone and octinoxate are restricted in areas with coral reef conservation laws but continue to be approved for human use in most countries. The European Scientific Committee on Consumer Safety has set concentration limits on homosalate pending further study. If you prefer to avoid these three, look for sunscreens that use UV filters like Tinosorb S, Tinosorb M, Uvinul A Plus, or mineral filters like zinc oxide and titanium dioxide. These are considered among the most stable and safety-reviewed options currently available.

Sources:
European Commission, Scientific Committee on Consumer Safety (SCCS), 2021 opinion on homosalate.