An advisory panel recommended that the sale of Primatene Mist and other similar non-prescription inhalers be banned as the devices contain propellants that harm the ozone layer.
The panel advised the US Food and Drug Administration that such inhalers were not 'essential' products, and hence their distribution should be stopped as they contain chlorofluorocarbons.
The FDA, which generally abides by the advice of its outside panel of experts, is yet to make a final decision that can take months.
Wyeth Consumer Healthcare, the makers of Primatene Mist, estimates that three million Americans use the product for mild or intermittent asthma, a company spokesman said. Two-thirds also use a prescription inhaler, but rely on Primatene as a backup. Others use Primatine alone because they do not have a prescription or lack health insurance.
Wyeth is the biggest maker of epinephrine inhalers, with $43 million in sales last year.
The inhalers, sold over the counter, contain the drug epinephrine along with chlorofluorocarbons, which propel the medicine into the lungs of asthmatics.
Chlorofluorocarbons have been used for years as aerosol propellants in a variety of products but are being phased out because they harm Earth's protective ozone layer.
Wyeth asked the FDA to stay any ban on Primatene Mist until the company was ready to market an approved version, said a company spokesman. Wyeth hopes to have such an inhaler ready for sale in 2009 or 2010.
"I would like to see people get proper treatment, and I think people who are using Primatene are not," said Dr. Kathleen Sheerin, an allergist with the Atlanta Allergy and Asthma Clinic.
Wyeth argued that the environmental risk from its product was small and justified given the benefit it provided.