Those little button batteries that are in so many children's toys this season can be a serious health hazard, health experts warn.

The batteries are among many holiday dangers that can put children and pets in peril and cause sickness during what is supposed to be a happy time of year.

Officials with the Arizona Poison and Drug Information Center say families should be on the alert for "seasonal poisons" like colorful over-the-counter cold and flu medication that children can mistake for candy.

Relatives from out of town can bring medications that are unfamiliar and children are curious by nature, said Keith Boesen, director of the local center.

Basic tree ornaments and color and snow sprays for windows can be dangerous when ingested. Other dangers include mistletoe, holly and Christmas berries, Boesen said.

"Just because you can buy a decoration at the store does not mean it is safe," he said.

Boesen added that families often visit relatives during the holidays and forget that not everyone lives in a childproof home.

"If you go over to someone else's house, be extra careful to keep an eye on children," he said. "There can be hidden hazards in a harmless toy."

Boesen noted a hazard with the magnetic desk toy Buckyballs. The Consumer Product Safety Commission sued the manufacturer this year because of grave hazards the small, magnetic balls pose to children who swallow them.

Button batteries are also extremely dangerous if swallowed, he stressed.

A study in the journal Pediatrics this year reported more than 5,500 battery-related emergency department visits in 2009 by people under age 18. Children age 5 and younger accounted for more than three-quarters of them, officials with the U.S. Department of Health and Human Services say.

Button batteries can burn a hole in a child's esophagus in less than two hours.

If parents think a child has swallowed a button battery, they need to go immediately to an emergency department to get an X-ray. Parents need to tell hospital officials they suspect it's a button battery, since that also means the clock is ticking.

Also, be careful of liquid candles and holiday scents - some ingredients in essential oils and flavors can be extremely toxic if ingested. As little as a teaspoon of oil of wintergreen, for example, is enough to be life-threatening to a 2-year-old.

The Pima Animal Care Center warns pet owners that allowing pets to slurp up Christmas tree water could lead to illness because the water can be a petri dish for bacteria and chemicals. And it's best for pet parents to steer clear of tinsel, officials say - cats in particular tend to play with it and eat it.

On a happier note, common holiday fears about poinsettia are mostly unfounded. The only hazard for young children could be an obstruction from a large leaf in the mouth.

"You might get an upset stomach, but it's not poisonous," Boesen said.

On StarNet: Stephanie Innes brings you the latest health information in her blog, Tucson Health and Wellness, at azstarnet.com/ news/blogs/health

If you go

Visit the free public display called "'Tis the Season to be Poisoned" in the Arizona Health Sciences Library Tucson Campus, Java City coffee-bar area, 1501 N. Campbell Ave. through Jan. 10 during library hours.

Poison Info

The Arizona Poison and Drug Information Center is available 24 hours a day, seven days a week, even during the holidays, at 1-800-222-1222. All calls are free and confidential. The center's experts provide information about medications, drugs, stings or bites by poisonous creatures, accidental poisonings, as well as medicines and chemicals during pregnancy or while breast-feeding.

Contact reporter Stephanie Innes at sinnes@azstarnet.com or 573-4134.