You know those individual rounded pods of laundry detergent, often packaged in smooth colorful plastic? Sort of look like pieces of candy? Well, many toddlers think they are candy. Earlier this month, in a two day period, four unrelated children showed up at Baystate Medical Center in Springfield with burns in the esophagus and airway from trying to eat the packets. Three of them went on ventilators. Christine McKiernan is director of Baystate’s pediatric intensive care unit.

“It was unusual to have that many in a short period of time,” McKiernan says. “But we have seen several over the course of the summer. And it is concerning that this is a kind of a new type of injury that we hadn’t seen before these detergent pods were available.”

The pods — known in the cleaning industry as liquid laundry packets — went on the market in 2011, and as their popularity rose, so did concern over accidental poisoning. Last year, the American Association of Poison Control Centers reported more than 10,000 of these exposures. Among the Baystate cases, Dr. McKiernan doesn’t necessarily blame parents for neglect.

“I think these were children that were well supervised,” she says. “One was a mom that had the baby with her, literally turned around long enough to step into the other room and step back, and watched him pick up the pod and as she reached to get it, saw it kind of go burst open in his mouth.”

And while McKiernan says obviously no detergent should be ingested, there’s something particularly toxic about the liquid pods.

“My understanding is the the PH is significantly higher on these pods because it’s a more concentrated detergent,” McKiernan says. “Whether that plays into it, I don’t think we know exactly why these seem to be worse than other detergents. Or is it that they’re more tempting to be put in mouths, is that the issue?”

Companies that make these detergent packets say they are aware of and concerned by the poisonings. Nancy Bock of the American Cleaning Institute — a trade group — says the industry has already made changes to the plastic pouches that hold the individual packets.

“We’re changing the packaging of the laundry liquid packets to opaque,” she says, “so that young children can’t see what’s in that packet.”

And Bock says the pouches have been made harder for children to open. But many parents take the individual pods out of the packaging and leave them lying on top of laundry baskets at home or at the laundromat. That’s one reason Bock says parent education is key.

“We just want to be sure that people know this product, and any other household cleaning product in the home, really needs to be stored up and out of reach so that we don’t have these situations happening,” she says.

Bock points out that millions of people find the pods convenient and use them safely — likewise for similar pods holding dishwasher detergent. She says liquid laundry packets are also considered environmentally friendly since there’s less packaging.

A spokesperson for Cooley Dickinson Hospital in Northampton says doctors there have not seen detergent poisonings in the recent past. and Dr. McKiernan says all the children who came to Baystate for eating laundry pods are doing fine.