The latest online kids craze is making your own slime. The do-it-yourself project has become so popular it's even caused some glue shortages in stores. But just how safe are the key ingredients?

Many slime recipes call for a combination of school glue, water and borax, a household cleaner. While borax may be safe to use for laundry, some experts are warning parents and kids to take precautions.

“Borax, also known as sodium tetraborate hexahydrate is meant to be a household cleaner. It’s not intended or meant to be used as a component for slime,” said James Dickerson with Consumer Reports.

The product even comes with a label that clearly states to keep out of reach of children.

“Borax is a known eye, nose and respiratory tract irritant. So we really don’t want young kids to be exposed to this because it’s a potential hazard,” warned Dickerson.

Fifth grader Kathleen Quinn, from Rockland, Massachusetts, recently suffered third degree burns to her hands after making slime.

Doctors determined her blisters came from prolonged exposure to borax.

"You just have to really read the packages, know what you're mixing because there are certain things in the home that are just dangerous," said pediatrician Dr. Megan Hannon.

Another concern is toddlers or younger children could get a hold of the slime or its ingredients and accidentally eat them.

For older children and adults, use common sense, avoid direct contact with your eyes and wash your hands after making and playing with the slime.

And remember, it’s always a good idea to store household cleaning and laundry products out of reach of children.

If borax does come into contact with your eyes be sure to rinse with plenty of water for 15 minutes. In case of accidental ingestion you can call B.C.’s Drug and Poison Information Centre.

Click here for a slime recipe that doesn't use borax. Elmer's glue also has a borax-free slime recipe.