Genetically Modified Ingredients in Corn and Corn-Based Products in Hong Kong


           The Centre for Food Safety (CFS) and the Consumer Council (CC) conducted a joint study on genetically modified (GM) ingredients in corn and corn-based products, to assess whether these products followed the recommendations set out in the "Guidelines on Voluntary Labelling of GM Food" (the Guidelines). The Guidelines were published in 2006 to lay down the principles underlying the recommended labelling approaches for GM food, and provide a reference for the trade to make truthful and informative labels in a consumer-friendly manner.

  1. The recommendations of the Guidelines are summarised as follows:-
    1. To label food items with 5% or more GM materials in their respective food ingredient(s) as "genetically modified" (positive labelling);
    2. Not to use negative labelling with absolute terms (e.g. "GM free") whereas other forms of negative labelling may be used only when such declaration can be substantiated by documentation; and
    3. To provide additional information on the label if the GM food concerned has undergone significant modifications in specific aspect (e.g. animal gene being introduced to food of plant origin).

The Study

  1. A total of 49 samples of corn and corn-based products (5 cob samples, 9 kernel samples, 6 soup samples, 4 cornmeal samples, 6 infant/young children food samples and 9 snack samples) were collected at the retail level, mainly from supermarkets. The presence and the amount of 10 GM corn events 1 were analysed by the Government Laboratory. Among these 49 samples, corn DNA was detected in 37 samples, and among them, 12 samples were detected with GM corn DNA.
  2. Five samples were found to contain GM corn contents exceeding the threshold value (5%). Nevertheless, none of them carried any positive "GM" labelling and hence did not follow the recommendation in the Guidelines. These 5 samples were all snack products imported from the United States. The CFS has issued advisory letters to remind vendors/distributors of these products to follow the recommendation as stipulated in the Guidelines, i.e. to add the term "GM" in their product labels.
  3. Thirteen samples were found to carry negative labelling, of which corn DNA was detected in 7 samples whilst only 2 of them were detected with GM corn content at levels less than 5%, thus were in line with the recommendation in the Guidelines. The CFS had requested vendors of these 13 products to submit relevant documentation. Ten vendors submitted acceptable documentation to substantiate that the respective corn ingredient was derived from non-GM sources. The remaining 3 distributors responded that they had deleted the negative labelling on their product labels.
  4. Among the 13 samples with negative labelling, 5 samples made with multiple ingredients were found to carry negative labelling for the products as a whole without specifying which ingredient(s) was/were derived from non-GM source. Some of the ingredients did not have GM counterparts on the market. The negative labelling on these samples did not follow the recommendations in the Guideline and may cause confusion to consumers. The CFS has issued advisory letters to remind vendors/distributors of these 5 products to follow the recommendations as stipulated in the Guidelines should they wish to label the food ingredients derived from non-GM source (which contains less than 5% of GM content). Distributors of 2 of these products had deleted the negative labelling on their product labels.
  5. The GM events tested in the study have all passed safety assessment conducted by overseas authorities, and thus, are unlikely to pose risk to the consumers. As stipulated in the Public Health and Municipal Services Ordinance (Cap. 132), all food available for sale in Hong Kong, including GM food, must be fit for human consumption.

Advice to the Public

Advice to the Trade

More Information

  1. The related article is published in the CHOICE MAGAZINE (Issue 438 released on 15 April 2013) (Chinese only).

April 2013
Risk Assessment Section
Centre for Food Safety
Food and Environmental Hygiene Department

1 A GM event refers to a GM crop carrying a specific recombinant DNA of interest. For example, Bt11 and MON810 represent two GM corn events that have been specifically inserted with different recombinant DNA to exert insect resistance.