(CNN) - The FDA is warning about the possibility of EpiPen malfunctions.
EpiPens are devices that deliver life-saving medication in cases of severe, potentially life-threatening allergic reactions.
According to the FDA, Manufacturing defects of user error could prevent them from working properly.
Pfiezer and Mylan make and distribute EpiPens.
Citing a letter from the companies, the FDA warned the devices could be difficult to remove from their carriers when receiving them.
Pfizer and Mylan gave recommendations for identifying potential problems.
They suggest trying to remove the EpiPens from the carriers when receiving them.
Also, people should watch for problematic safety releases.
The companies will replace defective devices for free.
For more information or to file a claim, click here.