Plant Protection Products
Risk assessment of Turex 50 WP with the active ingredient Bacillus thuringiensis
Report no: 2016: 20
It cannot be excluded that the use of pesticides containing Bacillus thuringiensis can bring cases of food poisoning. That is the main conclusion in a health and environmental risk assessment conducted by the Norwegian Scientific Committee for Food Safety (VKM). The Norwegian Food Safety Authority (NFSA) has requested the assessment.
We need better data for a more precise assessment. Intended use of Turex 50 WG will not pose a risk to the environment.
Applied for approval in Norway
Turex 50 WP is a new pesticide applied for approval in Norway. The intended use is as insecticide in a wide variety of crops. Turex 50 WP contain the organism Bacillus thuringiensis ssp. aizawai GC-91.
Bacillus thuringiensis is toxic to certain invertebrates, especially larvae belonging to the insect orders Coleoptera, Diptera and Lepidoptera. Different strains of Bacillus thuringiensis have been used as plant protective insecticides in many countries.
Several types of Bacillus bacteria
There are several types of the Bacillus bacteria which produce toxin, such as Bacillus cereus. The general consideration of Bacillus cereus as being pathogenic, and Bacillus thuringiensis being unproblematic, seems not to be supported by available data. It is the opinion of VKM that there are more quantitative than qualitative differences between different strains of Bacillus cereus and Bacillus thuringiensis with regard to some of the aspects of importance for possible effect on human health, especially the formation of enterotoxins. Existing studies should be supplemented with data based on new and modern methods on how to categorize microbes. Also non-rodent species should be considered as test organisms.
It is the opinion of VKM that the potential for harmful effects caused by transfer of genetic material in the environment is low. The fact that such gene transfer may take place highlights however the importance of procedures for analysis and control of purity, genotypic and phenotypic properties of the active ingredients.
Does not exclude food poisoning
According to VKM it cannot be ruled out that the use of pesticides containing Bacillus thuringiensis can lead to cases of food poisoning. Residual bacterial spores may create toxin-producing bacteria. To gain more knowledge about the risk for food poisoning, there is a need for better data on the conditions of use in Norway and the Nordic countries.
VKM considers it unlikely that the use of Bacillus thuringiensis pesticide will pose a threat to human health via drinking water.
No environmental risk
VKM find it unlikely that the spores or the protoxins/toxins will translocate to groundwater, or that the use of Turex 50 WG will result in increased density of Bacillus thuringiensis in Nordic soils.
By following regulations for use, Turex 50 WG will not pose a risk to the environment, concludes VKM.
VKM’s Panel on Plant Protection Products has approved the risk assessment.