Which local anesthetic is associated with methemoglobinemia in infants when used topically?

BENZOCAINE (ester type) metabolizes to PABA derivatives that oxidize Hgb Fe2+ → Fe3+ (methemoglobin), impairing O2 transport. Especially dangerous in infants (<2 years) with immature methemoglobin reductase. FDA warns against benzocaine teething gels in children <2.