Coin- and button-sized batteries from common electronic gadgets can be harmful if swallowed.

If the list of hazards awaiting your vulnerable young child seems never-ending, brace yourself for the results of two studies published online today in the journal Pediatrics. Button-size batteries like the one in your TV remote or calculator send a child to the Emergency Room every three hours in the U.S. And bottles, pacifiers and sippy cups aren’t much safer, injuring a child severely enough for an ER visit every four hours.

Both studies used 20 years worth of reports (1990-91 to 2009-10) from the National Electronic Injury Surveillance Data System (NEIS), a government database that collects information on product-related injuries across the country, and were conducted by Nationwide Children’s Hospital.

New coin- and button-size batteries now common in games, remote controls and other electronics doubled the number of battery-related injuries during the past eight years, researchers noted. Most of these (more than 80%) were to children younger than 5.

Overall around 66,000 children went to the ER with battery-related injuries during the study period. The majority fished button-size batteries out of products and swallowed them. If a battery makes it through to the digestive tract, most will pass through without causing harm. However, if a battery lodges in the throat it can take as little as two hours for current from the battery conducted by saliva, or leakage from the battery, to permanently damage the esophagus, vocal cords or surrounding nerves. This can paralyze tissues or cause a child to bleed to death. No deaths were reported in the study, but the authors note that the NEISS database does not do a good job of tracking deaths.

Smaller numbers of children were taken to the ER with batteries lodged in their noses or ears.

To keep batteries out of children’s hands, etc., experts recommend that parents tape shut the battery compartments of all electronic devices in their homes, and store extra batteries well out of children’s reach. Ultimately, they say manufacturers should design battery compartments that can’t be opened without a screwdriver.

Toddlers walking around (unsteadily) while drinking from a bottle can get hurt if they fall.

The data on bottles, pacifiers and sippy cups are new not because of the products, but because of the focus. Previous research centered around choking from broken pacifier parts and burns from overheated formula in bottles. This study looks at a range of injuries caused by these products – most to children around age 1, who were walking around sucking pacifiers or drinking from bottles or sippy cups, and fell. Only around 4% of more than 45,000 injuries recorded over 20 years were caused by any sort of product malfunction. Cuts and bruises to the mouth, lips, teeth and face were the most common injuries noted.

Recommendations about use of pacifiers, bottles and sippy cups focus on protecting the teeth from decay (in the case of bottles and sippy cups) and becoming crooked (in the case of pacifiers), rather than preventing injuries. Experts suggest that by age 1, children should be transitioned away from these products and drinking only from lidless cups.

Research has shown, however, that children commonly continue to use these products through age 2 and beyond. The authors of this study suggest that parents consider the risk of injury to children who are learning to walk, encourage their children to stay seated while drinking, and help them transition away from bottles, pacifiers and sippy cups by age 1. Just to be safe.