What to look for when choosing sunscreen for your kids: Your sun protection questions answered

As Health Canada investigates allegations of babies being burned while wearing Banana Boat sunscreen, concerns about sun safety have been front and centre in recent days.

CBC News asked Dr. Cheryl Rosen, head of dermatology at the University Health Network in Toronto, to answerviewers' questions about sunscreen during a Facebook Live session hosted by health reporter Christine Birak.

Here's some of the advice Rosen gave on how to protectyourself and your childrenagainst sunburn, skin cancer, premature aging and other skin damage that sun exposure can cause.

Is sunscreen safe to use on kids?

Yes, Rosen says. It's an important way to protect their skin.

Past recommendations have advised against using sunscreen on babies six months old or younger. The best practice is still to keep children that young out of the sun, she says.But if that's not possible, guidelines out of the U.S. suggest a little bit of sunscreen on their hands and face is OK.

Sunscreen is a good way to protect older babies (who are walking, and harder to keepout of the sun) and children, Rosen says.She recommends additional protection includinga hat and clothing covering as much of their bodies as possible, and trying to plan outdoor activities for earlier and later in the day when the sun's rays are less intense.

How often should I apply sunscreen on my children?

Health Canada recommends reapplying sunscreen every two hours. But if children are sweating or swimming, parents and caregivers should reapply it more often.

How do I know how much sunscreen to put on?

Most people don't put on as much sunscreen as the lotion makers use while testing effectiveness, Rosen says.Make sure you cover every exposed area of your body including often forgotten parts like the ears, she says.

What about allergies?

In response to the concerns about babies being burned, Banana Boat Canada has suggested that a bad skin reaction may be due to a sensitivity to a particular ingredient.

Sunscreens are made up of many ingredients, including not only the active compounds that absorb UVA and UVB rays to prevent them from getting into the skin, but also addedfragrances and preservatives, Rosen says. None of the ingredients are toxic, she says, but it's possible that someone could have a sensitivity to an individual component.

If that's the case, it's important to get allergy testing to find out what the specific problematic ingredient is and then choose a sunscreen that doesn't contain it, rather than avoiding sunscreen altogether, Rosen says.

Are 'organic'sunscreens found in health food stores effective?

Although people say "organic"sunscreens don't contain chemicals, they do contain titanium and zinc oxide, which makes them effective, Rosen says. Make sure you use one with an SPF of 30 or higher.

What is SPF and how high should it be?

SPF, or sun protection factor, is a ratio indicating how much more time skin can be exposed to the sun with sunscreen on without burning versus if no sunscreen were used.

People should use an SPF of at least 30, Rosen says, but recommends going higher to 45 or 60 SPF to maximize protection.

But she cautions against thinking that it's OK to stay in the sun 30 times longer if you're wearing 30 SPF sunscreen, because skin damage that can lead to premature wrinkling or skin cancer occurs before the skin burns.

People may also find it helpful to look for a seal that the sunscreen is recognized by the Canadian Dermatology Association, she says.

According to the Canadian Dermatology Association's website, recognized sunscreens meet the following criteria:

• SPF of 30 or higher.
• Broad spectrum (protection against UVA and UVB rays).
• Non-irritating and hypo-allergenic.
• Minimally perfumed or non-perfumed.
• Non-comedogenic(does not block pores).

Is it possible to get sunburned while wearing sunscreen?

Yes, Rosen emphasizes. It's important to remember that it's called "sunscreen" and not "sunblock" for a reason. Some UVA and UVB rays still get through.

In addition, there is no such thing as completely "waterproof" sunscreen, she notes. Rosen recommends water-resistant sunscreen, but remember to reapply itafter being in the water.

• Watch the Facebook Live with Dr. Cheryl Rosen