Q. Which ingredients should I avoid in sunscreen?

A. We all need to use sunscreen daily to protect our skin. But if you have sensitive or dry skin—or if you're slathering up young children—you'll probably want to be more discerning about exactly what's in that bottle you're buying.

Here are some ingredients you may want to avoid:

• PABA (para-aminobenzoic acid): Can trigger an itchy rash.
• Benzophenones (such as dioxybenzone, oxybenzone, or sulisobenzone): Cause rashes, acne, dryness, and itching in some people.
• Alcohol: Can be drying and cause skin allergies in sensitive individuals.
• Fragrances: Can set off skin reactions in very sensitive skin.
• Some preservatives (especially quaternium-15): Can trigger allergic skin reactions.
• Parabens (methylparaben, propylparaben, ethylparaben): Recent studies found high concentrations of these chemicals—common preservatives and antimicrobials—in breast cancer tissue. No clear links have been established, but many health-oriented manufacturers are removing them from their formulas just in case.

For optimal skin protection—and minimal irritation risk—choose a broad-spectrum sunscreen, which blocks both UVA and UVB rays.

Active ingredients to look for:

• Avobenzone (Parsol 1789): Provides broad-spectrum skin protection; less likely than other chemicals (such as PABA) to trigger a skin reaction.
• Titanium dioxide or zinc oxide: Protect skin by physically (as opposed to chemically) blocking, scattering, and absorbing harmful rays.

A note about sunscreen and babies: It's best to keep babies younger than 6 months out of direct sunlight. But the American Academy of Pediatrics now recommends applying sunscreen to infants on small areas (such as the face and back of the hands) if clothing protection and shade will be inadequate.

Finally, consider doing your skin a favor and avoiding the midday sun, which is more likely to cause sunburns. If you're craving a bronzed look, try out one of the great, natural sunless tanners that are on the shelves these days. You'll get all the glow—without the risks.