A distributor of concentrated Chinese herbs is voluntarily recalling all supplies of a 100 ml bottle of cough syrup called Licorice Coughing liquid to the consumer level as the product was detected to contain morphine, which is an opioid.

The California-based company named Master Herbs, Inc. issued on Wednesday the nationwide recall of the cough syrup because it contained opioid, an ingredient of the compound camphor. The compound was identified on the product's label, but opioid and other ingredients were undeclared.

According to a press release submitted to the United States Food and Drug Administration (FDA), consumers of the cough syrup may not be aware that they are ingesting morphine. Not knowing that you are taking morphine can result in life-threatening hypoventilation – when air circulation is inadequate for breathing – and consequently, death.

Because morphine was not declared on the label, there is also a risk that patients hypersensitive to it could suffer severe allergic reactions, experts said.

Young children who are diagnosed with respiratory illnesses and take the cough syrup are vulnerable to hypoventilation as an effect of the opioid intake. They should not be exposed to morphine in any event.

Master Herbs, Inc. has not been made aware of the adverse effects that come with the use of the cough syrup, the company said.

The company is pulling all lots of the Licorice Coughing liquid sold in Chinese grocery stores in New Jersey, California, Illinois, Ohio, Nevada and Hawaii.

The company is also notifying all its customers and distributors by fax or phone and is arranging for the recall of all deliveries of the product.

Consumers who still have the product are advised to stop using it and return it to the place of purchase. Wholesalers and retailers should stop distributing the cough syrup, quarantine remaining supplies and make arrangements to bring the product to the company.

Master Herbs, Inc. is urging consumers and distributors to contact the FDA's MedWatch Adverse Event Reporting program, call the company on its phone number 626-319-9915, or email 999herbs@gmail.com for any reports of adverse reactions due to the product.

The Licorice Coughing liquid product is used to provide temporary relief from coughs, as well as minor bronchial and throat irritations.