Safety experts have urged parents and caregivers to avoid using or purchasing car seats for their children that do not meet federal safety standards.

The US Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) has made the appeal after being alerted by a concerned pediatrician about safety concerns regarding child seats being sold in the United States.

Tell-tale signs that a car seat does not meet Federal Motor Vehicle Safety Standards (FMVSS) and may pose significant risk to an infant include seats without lower anchor attachments, without proper labeling, lacking a chest clip, or only secured by a seat belt crossed over the seat and not correctly installed, the NHTSA said.

More information, including a list of child car and booster seats that are certified as meeting FMVSS, is available on the NHTSA website on the Car Seats and Booster Seats section. Ease-of-use car seat ratings are also available online.

The public is encouraged to report suspected safety issues and concerns about car seats or other child restraints to NHTSA’s Vehicle Safety Hotline at 888-327-4236 or by filing a non-vehicle complaint.