The 2019 reassessment of the pesticide sulfoxaflor and, in particular, its impact on bees and other pollinators

1. What is sulfoxaflor and what is it used for?

Pesticides are used to protect crops against insects, and therefore to maximise their yield. In the recent years, a specific class of insecticides, the neonicotinoids, were demonstrated to have negative impacts, in particular on pollinator insects, which led many countries² to progressively ban their uses, except within greenhouse structures.

These facts and subsequent trends have led to the development and registration of alternatives products, among which sulfoximine-based insecticides. Some of these, in particular sulfoxaflor were progressively registered in various regions, including the USA and the EU.

However, since several years some studies reported that the sulfoximine insecticides could equally represent a risk for pollinators. The representative uses assessed were foliar spraying treatments on fruiting vegetables, spring and winter cereals and cotton to control sap feeding insects. These substances act indeed in a novel way on the central nervous system of insects such as aphids, which have developed resistance to other pesticides, and by acting on sap-like insect-type receptors.

^1,2 See the GreenFacts Highlights on: Neonicotinoids, bees, ecosystem services and agriculture

2. What are the conclusions of the EFSA reassessment of 2019 on the risks raised by sulfoxaflor used as a pesticide?

For the field and non‐permanent structure greenhouses, a high risk to honeybees and bumble bees was identified related to some pertinent scenarios (treated crop scenario except after flowering period, weed scenario, field margin scenario). In case of permanent structure greenhouse, considering the low exposure in such scenarios, a low risk was concluded for honeybees, bumble bees and solitary bees.

These conclusions were reached on the basis of the evaluation of the representative uses of sulfoxaflor as an insecticide on fruiting vegetables (field and greenhouse application), cucurbits (field and greenhouse application), spring and winter cereals (field application), and cotton (field application).

3. What are the hazards and risks associated with sulfoxaflor?

For humans: Sulfoxaflor is almost completely absorbed after oral administration and most of it is rapidly excreted in urine and faeces. It is harmful if swallowed, and causes problems in the liver, but it is not acutely toxic through the skin or if breathed in. It is neither a skin or eye irritant, nor a skin sensitiser.

Sulfoxaflor is not classified as carcinogen, toxic to reproduction, or endocrine disruptor.

For the environment , it has been found that there is a risk from sulfoxaflor to birds, to ladybugs, and mainly to sap-sucking species such as ants s and, if they come into contact with spray droplets shortly after application, to pollinator insects, especially honey bees. A high risk was concluded for the situations when sulfoxaflor was used in flowering stage of the representative crops (even if it was an evening application). A low risk could be concluded for the situations when sulfoxaflor was used at least 5 days before the flowering period starts. Even in the case where sulfoxaflor was used in enclosed, greenhouse conditions, the risk to bees could not be excluded.

There is also a low risk to mammals and aquatic organisms.

4. How are the uses of sulfoxaflor regulated?

In the European Union , sulfoxaflor was approved in 2015 with the specific provision that the applicant was required to submit by August 2017 to the European Commission further studies on the risks to bees and other pollinators. In accordance with these specific provisions, the applicant, Dow AgroSciences, submitted an updated dossier to the rapporteur Member State Ireland in August 2017 and EFSA finalised the related technical report in July 2018. Meanwhile, there is no obligation for the European Commission to review the authorisations of uses for sulfoxaflor.

Besides, in April 2018, the Standing Committee on Plants, Animals, Food and Feed of the European Union, expanded a controversial ban on 3 neonocotinoids (clothianidin, imidacloprid and thiamethoxam) on the ground that they pose a threat to pollinators. Only the uses in greenhouses without contact with bees remain authorised.

In the USA , although the Environmental Protection Agency (EPA) itself considered this substance “very highly toxic” to bees, in 2018, through so-called “emergency” approvals³ , sulfoxaflor was granted a full registration on more than 16 million acres of crops known to attract bees, even if the EPA’s 2016 registration purportedly excluded its use in crops like cotton and sorghum that are known to be attractive to bees.

In France , according to the Agency for food, environmental and occupational health and safety (ANSES), the advantages of sulfoxaflor over neonicotinoids are that it is not very persistent in soils and plants; it is less toxic to aquatic animals and its degradation residues would not be toxic to pollinators. However, in 2017, by application of the precautionary principle, the marketing authorization issued by ANSES was suspended in France.

References:
1. Conclusion on the peer review of the pesticide risk assessment for the active substance sulfoxaflor in light of confirmatory data submitted. Abdourahime H et al, European Food Safety Authority (EFSA), 2019. EFSA Journal 2019;17(3):5633, 14 pp. https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2019.5633
2. Conclusion on the peer review of the pesticide risk assessment of the active substance sulfoxaflor. EFSA, 2014. EFSA Journal 2014; 12(5):3692, 170 pp. https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2014.3692
3. COMMISSION IMPLEMENTING REGULATION (EU) 2015/1295 of 27 July 2015 approving the active substance sulfoxaflor, in accordance with Regulation (EC) No 1107/2009 of the European Parliament and of the Council concerning the placing of plant protection products on the market, and amending the Annex to Commission Implementing Regulation (EU) No 540/2011. https://publications.europa.eu/en/publication-detail/-/publication/e5aad62c-35b1-11e5-9f85-01aa75ed71a1/language-en

³ www.federalregister.gov/documents/2018/05/31/2018-11751/pesticide-emergency-exemptions-agency-decisions-and-state-and-federal-agency-crisis-declarations