Genetically engineered plants resistant to herbicides were specifically developed to allow the application of broad spectrum herbicides, especially glyphosate, in agriculture. The ongoing and large-scale applications of these herbicides has led to many weeds adapting to the use of glyphosate. Consequently, increased amounts of herbicides are being sprayed in the US and other countries where the plants are cultivated. The residues left from spraying with these herbicides are present in the harvested soybeans – and these are being imported into the EU for use in food and feed.
A short time ago, genetically engineered plants developed to be resistant to several herbicides were authorised for import into the EU. These include soybeans produced by Bayer and Monsanto that can be sprayed with glyphosate in combination with dicamba or isoxaflutole and sold under brand names, such as 'Balance GT' or 'Roundup Ready 2 Xtend Soybeans'. The herbicide isoxaflutole is classified as being suspected to be carcinogenic. There are also warnings about glyphosate being probably carcinogenic.
What is the problem?
In some regions the herbicides are applied in very high dosages, especially where there are problems with herbicide resistant weeds. The EU has, as yet, failed to assess the specific commercial formulations applied in these countries, or any health risks associated with them. At the same time, it is well-known that the formulations can be much more toxic in comparison to an active ingredient in its isolated form; and the combination of the formulations can be much more toxic than each of them separately. Despite these well-known facts, the EU has still not requested an assessment of the residues from spraying.
Many genetically engineered plants are purposely sprayed with specific herbicides. The respective residues left behind are unavoidable constituents of derivative food and feed and, therefore, need to be assessed before being approved. EU Regulation 1829/2003 requests that genetically engineered plants can only be allowed on the market if they are shown to be safe as a whole. If these plants are burdened with a combination of potentially toxic residues, they must be assessed before they are allowed for import.
In 2015, the European Food Safety Authority published its opinion on the risks of the herbicide glyphosate and stated that commercial formulations, such as Roundup with glyphosate as the active ingredient, were considered to have a much higher degree of toxicity than glyphosate alone. At the same time, according to EFSA, it is not possible to assess the health impact of the residues from these commercial formulations because no data are available. There is a similar problem with isoxaflutole: According to EFSA, there are metabolites from this herbicide that have been found in the genetically engineered soybeans, none of which have been investigated in regard to health risks. For this reason, Testbiotech has filed a legal case at the EU court against import of these soybeans into the EU (T-173/17).