Parents are being warned that fake or counterfeit versions of their children’s favorite toys may put them in danger.

The U.S. Consumer Product Safety Commission warned in an August 5 notice against fake or counterfeit squishy toys — and cautioned against a viral social media trend that encourages children and teens to microwave them.

These toys, which can resemble popular characters, animals or food, are sold online, on social media and at discount stores and other retailers.

Viral videos show these toys expanding, changing texture or even bursting when they are heated up.

However, the commission warns that these trends are “dangerous and should never be attempted or imitated.”

In January, a 9-year-old boy in Plainfield, Illinois, suffered burns to his face and hands when he microwaved a NeeDoh toy, which exploded, covering him in scalding goo, reported the New York Times. The youngster was taken to the emergency room and later transferred to a burn center where he was treated for second-degree burns .

Some versions of them do not comply with federal safety requirements for children’s toys. Some squishy toys contain water beads, gels, liquids, powders or sand. If the toys burst, children may be exposed to the contents.

“Water beads can expand after being swallowed and cause intestinal blockages, choking, aspiration, or injuries when inserted into the nose or ear. Other unknown filling materials may present chemical exposure, inhalation, or ingestion hazards,” the CPSC warned.

The CPSC also warned that some fake toys may break or tear during use, releasing hazardous materials or contain excessive amounts of lead, prohibited phthalates or other chemicals.

Some also fail to comply with federal requirements governing water beads, lack required warnings, age grading, tracking information or manufacturer identification. They may also be sold without testing and certification required for children’s products.

The commission has identified 55 shipments of these dangerous toys at U.S. ports, and worked with U.S. Customs and Border Protection to prevent 355,683 units from entering the country.

The CPSC recommends that parents and caregivers purchase toys from reputable retailers, be cautious of unusually low prices, check packaging for misspelled words or missing manufacturer information or safety warnings and keep damaged toys away from children.

The commission says that if a burn should occur as a result of the toys, the affected area should immediately be placed under cool running water for at least 20 minutes.

Gently washing the area with mild soap and water also helps to remove any remaining material.

Medical attention should be sought for a severe burn, a burn involving a young child, or if there are signs of an infection after the burn.