Full Draft Assessment Report available [ pdf ]
An application was received from Monsanto Australia Ltd on 30 April 1999 for the approval of food from genetically modified (GM) corn containing transformation event DBT418. The corn has been genetically modified to be protected from insect attack from the European corn borer (ECB) and tolerant to the herbicide glufosinate ammonium. The corn is commonly known as ' DBT418 corn' . This report describes the scientific assessment of the application.
Food from glufosinate ammonium -tolerant DBT418 corn has been evaluated according to the safety assessment guidelines prepared by ANZFA. The assessment considered the following issues: (1) the nature of the genetic modification; (2) general safety issues such as novel protein expression and the potential for transfer of antibiotic resistance genes to microorganisms in the human digestive tract; (3) toxicological issues; and (4) nutritional issues.
Nature of the genetic modification
Four genes were stably transferred to DBT418 corn using microprojectile bombardment -cryIAc,bar, pinII andbla. Thebar gene, which is responsible for the herbicide-tolerance trait, was used as a selectable marker.
The cryIAc gene is derived fromBacillus thuringiensis subspecies kurstaki and encodes the insecticidal crystal protein CryIAc, which is toxic to Lepidopteran insects, including the European corn borer (ECB). The bargene is derived from Streptomyces hygroscopicus and encodes the enzyme phosphinothricin acetyltransferase (PAT) which inactivates phosphinothricin (PPT), the active constituent of glufosinate ammonium herbicides. The blagene is derived fromEscherichia coli and codes for the enzyme b -lactamase which confers resistance to a number of b -lactam antibiotics such as ampicillin. The bla gene is used as a marker to select transformed bacteria from non-transformed bacteria during the DNA cloning and recombination steps undertaken in the laboratory prior to transformation of the plant cells. The pinII gene is derived from potato (Solanum tuberosumL.) and encodes a serine protease inhibitor that is reported to enhance the insecticidal activity of CryIAc against various lepidopteran pests. The pinIIgene in DBT418 corn is non-functional and does not give rise to any protein products.
General safety issues
Corn (Zea maysL.) is used as a staple food by a significant proportion of the world' s population. Corn-based products are routinely used in large number and diverse range of foods, and have a long history of safe use. Products derived from DBT418 corn may include highly processed corn products such as flour, breakfast cereals, high fructose corn syrup and other starch products.
DBT418 corn was shown to produce two new proteins - CryIAc and PAT. PAT is expressed at significantly higher levels than CryIAc in DBT418 corn. In kernels, mean CryIAc levels ranged from 36.0 - 42.8ng/g dry weight (equivalent to about 0.0001% of the total protein) and mean PAT levels ranged from 3.1 - 6.0 micrograms/g dry weight (equivalent to about 0.0175% of the total protein). Higher levels of CryIAc and PAT were detected in other parts of the plant, particularly the leaves, however these are not used for human consumption.
The impact on human health from the potential transfer of an antibiotic resistance gene to microorganisms in the human digestive tract was considered. The presence of the bla gene in DBT418 corn was not considered to pose any additional safety concerns.
Corn contains no naturally occurring toxins or allergens and, as noted above, has a long history of safe use. In addition, the Cry proteins from B. thuringiensis have a long history of safe use as insecticides.
The newly expressed CryIAc and PAT proteins in DBT418 corn were evaluated for their potential to be toxic to humans using acute toxicity testing in animals and were also assessed for their potential to be allergenic. The evidence does not indicate that there is any potential for either CryIAc or PAT to be toxic to humans and also indicates that both proteins have limited potential as food allergens. Furthermore, as the CryIAc and PAT expression levels in corn kernels are low, exposure to both proteins through the consumption of DBT418 corn products would be very low, and certainly well below the levels found to be safe in acute toxicity tests using animals.
Compositional analyses were done to establish the nutritional adequacy of DBT418 corn, and to compare it to non-transgenic control lines. The components measured were protein, oil, moisture, starch, fibre, ash, fatty acids, amino acids, as well as the minerals phosphorous and calcium. No significant differences in the levels of these major constituents or nutrients between transgenic and control lines were observed. Therefore, on the basis of the data submitted in the present application, DBT418 corn can be considered compositionally no different to other commercial corn varieties.
No potential public health and safety concerns have been identified in the assessment of DBT418 corn. Therefore, on the basis of the data provided in the present application, foods derived from DBT418 corn are considered to be as safe and wholesome as foods derived from other corn varieties.
Under the recently adopted Standard (A18 in the AustralianFood Standards Code, 1.5.2 in the Australia New Zealand Food Standards Code) which came into effect on 7 December 2001, food products made using DBT418 corn will require labelling if it can be shown that novel DNA and/or protein is present in the final food.
(iii) Public submissions
Forty-five public submissions were received in relation to this application, of which only four were supportive. Those opposing the application did so primarily on the basis that they perceive GM food to be unsafe. The food safety concerns raised in submissions have been addressed by the safety assessment carried out by ANZFA.
On the basis of the data submitted with the application and evidence obtained from the scientific literature it is concluded that:
- the introduced genes in DBT418 corn are not considered to produce any additional public health and safety risk;
- food from DBT418 corn is as safe and wholesome as food from other commercially available corn varieties ;
- from 7 December 2001, food products containing DBT418 corn will require labelling if it can be shown that novel DNA and/or protein is present in the final food;
- the proposed amendment to theFood Standards Codeis consistent with the section 10 objectives of theAustralia New Zealand Food Authority Act1991 and the regulatory impact assessment.
On the basis of the available evidence, ANZFA considers that food from DBT418 corn is as safe for human consumption as food from other commercial corn varieties and is therefore proposing an amendment to theFood Standards Codeto give approval to the sale of such food in Australia and New Zealand.
ANZFA now seeks public comment on the proposed amendment in accordance with the procedures described in Section 16 of the Australia New Zealand Food Authority Act 1991.
The Governments of Australia and New Zealand entered an Agreement in December 1995 establishing a system for the development of joint food standards. On 24 November 2000, Health Ministers in the Australia New Zealand Food Standards Council (ANZFSC) agreed to adopt the new Australian New Zealand Food Standards Code. The new Code was gazetted on 20 December 2000 in both Australia and New Zealand as an alternate to existing food regulations until December 2002 when it will become the sole food code for both countries. It aims to reduce the prescription of existing food regulations in both countries and lead to greater industry innovation, competition and trade.
Until the joint Australia New Zealand Food Standards Code is finalised the following arrangements for the two countries apply:
- Food imported into New Zealand other than from Australiamust comply with either Volume 1 (known as AustralianFood Standards Code)or Volume 2 (known as the jointAustralia New Zealand Food Standards Code)of the AustralianFood Standards Code, as gazetted in New Zealand, or the New ZealandFood Regulations 1984,but not a combination thereof. However, in all cases maximum residue limits for agricultural and veterinary chemicals must comply solely with those limits specified in the New Zealand(Maximum Residue Limits of Agricultural Compounds) Mandatory Food Standard 1999.
- Food imported into Australia other than from New Zealandmust comply solely with Volume 1 (known as AustralianFood Standards Code)or Volume 2 (known as the jointAustralia New Zealand Food Standards Code)of the AustralianFood Standards Code, but not a combination of the two.
- Food imported into New Zealand from Australiamust comply with either Volume 1 (known as AustralianFood Standards Code)or Volume 2 (known asAustralia New Zealand Food Standards Code)of the AustralianFood Standards Codeas gazetted in New Zealand,but not a combination thereof. Certain foods listed in Standard T1 in Volume 1 may be manufactured in Australia to equivalent provisions in the New ZealandFood Regulations 1984.
- Food imported into Australia from New Zealandmust comply with Volume 1 (known as AustralianFood Standards Code)or Volume 2 (known asAustralia New Zealand Food Standards Code)of the AustralianFood Standards Code, but not a combination of the two. However, under the provisions of the Trans-Tasman Mutual Recognition Arrangement, food mayalsobe imported into Australia from New Zealand provided it complies with the New ZealandFood Regulations 1984.
- Food manufactured in Australia and sold in Australia must comply with Volume 1 (known as AustralianFood Standards Code)or Volume 2 (known asAustralia New Zealand Food Standards Code)of the AustralianFood Standards Codebut not a combination of the two. Certain foods listed in Standard T1 in Volume 1 may be manufactured in Australia to equivalent provisions in the New ZealandFood Regulations 1984.
In addition to the above, all food sold in New Zealand must comply with the New Zealand Fair Trading Act 1986 and all food sold in Australia must comply with the AustralianTrade Practices Act 1974,and the respective Australian State and TerritoryFair Trading Acts.
Any person or organisation may apply to ANZFA to have the Food Standards Code amended. In addition, ANZFA may develop proposals to amend the Australian Food Standards Code or to develop joint Australia New Zealand food standards. ANZFA can provide advice on the requirements for applications to amend the Food Standards Code.
Full Draft Assessment Report available [ pdf ]