Here is a warning from the US government in April 2011:
FDA: Oragel and other benzocaine products may be dangerous to babies!
[04-07-2011] The U.S. Food and Drug Administration (FDA) is warning the public that the use of benzocaine, the main ingredient in over-the-counter (OTC) gels and liquids applied to the gums or mouth to reduce pain, is associated with a rare, but serious condition. This condition is called methemoglobinemia and results in the amount of oxygen carried through the blood stream being greatly reduced. In the most severe cases, methemoglobinemia can result in death.
Benzocaine gels and liquids are sold OTC under different brand names such as Anbesol, Hurricaine, Orajel, Baby Orajel, Orabase, and store brands. Benzocaine is also sold in other forms such as lozenges and spray solutions (also see separate Drug Safety Communication on Benzocaine Sprays1). These products are used to relieve pain from a variety of conditions, such as teething, canker sores, and irritation of the mouth and gums.
Methemoglobinemia has been reported with all strengths of benzocaine gels and liquids, including concentrations as low as 7.5%. The cases occurred mainly in children aged two years or younger who were treated with benzocaine gel for teething. People who develop methemoglobinemia may experience pale, gray or blue colored skin, lips, and nail beds; shortness of breath; fatigue; confusion; headache; lightheadedness; and rapid heart rate. In some cases, symptoms of methemoglobinemia may not always be evident or attributed to the condition. The signs and symptoms usually appear within minutes to hours of applying benzocaine and may occur with the first application of benzocaine or after additional use. If you or your child has any of these symptoms after taking benzocaine, seek medical attention immediately.
Benzocaine products should not be used on children less than two years of age, except under the advice and supervision of a healthcare professional. Healthcare professionals and consumers are advised to consider the American Academy of Pediatrics’ recommendations for treating teething pain instead of using the benzocaine teething products:1,2
- Give the child a teething ring chilled in the refrigerator.
- Gently rub or massage the child’s gums with your finger to relieve the symptoms of teething in children.
If these methods do not provide relief from teething pain, consumers should talk to a healthcare professional to identify other treatments.
Adult consumers who use benzocaine gels or liquids to relieve pain in the mouth should follow the recommendations in the product label. Consumers should store benzocaine products out of reach of children. FDA encourages consumers to talk to their healthcare professional about using benzocaine.