Dongwon F&B has begun a voluntary recall of its mild tuna products in response to consumer concerns over an unidentified black substance in some of the cans, the company said Friday.

The recalled product is the brand’s Mild Tuna 210 g, marked with expiration dates from March 23 to April 25, 2021. The company said that about 1.17 million cans will be collected from consumers and retailers.

Dongwon said through a statement that the black substance was caused by “high heat in the manufacturing process” and that it was “judged to have no harmful effects on the human body.”

The Ministry of Food and Drug Safety is currently conducting an investigation on the unidentified substance.

Consumers who wish to return products should contact the Dongwon F&B customer center at (080) 589-3223.

By Won Ho-jung (hjwon@heraldcorp.com)