EU authorisation of pyrethrum-based products: preliminary work needed

December 01, 2021

Two Chrysanthemum cinerariaefolium extracts currently making their way through the review programme under the EU Biocidal Products Regulation are expected to be approved as biocidal active substances for Product Type (PT) 18 (insecticides) and 19 (repellents) in December 2023. Companies intending to submit an application for EU product authorisation should consider undertaking preliminary risk assessment and developing an efficacy testing strategy now. 

Preliminary risk assessment

Biocidal products based on pyrethrum, used either alone or in combination with other already-approved active substances such as piperonyl butoxide, cypermethrin, permethrin, s-methoprene or margosa extract have historical efficacy test data. However this test data does not meet current efficacy guidelines, and conducting new testing at the existing application rate may lead to poor efficacy results and claims that are difficult to support.

In addition, pyrethrins and pyrethroids are classified for the environment and the very conservative emission scenarios can be incredibly challenging to pass. Space spray for flying insects and ant baits will need inventive refinements to reduce the risk to acceptable levels for both indoor and outdoor uses.

Having an in-depth scientific understanding of such products – by performing a preliminary risk assessment and developing a robust efficacy strategy – will enable companies to balance efficacy and acceptable risk.

Post-approval data required as part of the PT 18 approval of permethrin has resulted in the substance now meeting the candidate for substitution criteria. For a pyrethrum-based product also containing permethrin, a comparative assessment will be performed by the evaluating authority as part of the evaluation

Capacity constraints

Finding an evaluating competent authority to assess dossiers may be challenging with similar approval dates anticipated for two widely-used quaternary ammonium compounds. Companies should therefore begin discussions with their chosen country competent authority as soon as possible to lock in agreement to take the dossier. Leave it too late and the chosen authority may be full, meaning an alternative authority needs to be found.

Capacity at efficacy test sites for trials including field trials and seasonal availability of some insects are also important aspects to consider at an early stage. 

How can TSG help?

Determining a biocidal product’s claims and the efficacy testing needed to support them while demonstrating safe risk is a challenge that TSG Consulting routinely helps companies overcome. Efficacy data is the cornerstone of a dossier and our scientific and regulatory consultants help companies find the balance between application rate and safe risk. We also support companies in adapting their products to comply with changing requirements.

TSG’s team of consultants and scientists have many years’ experience working in the field of insecticides and repellents. We are familiar with the requirements for biocidal products containing pyrethoid and plant-derived active substances, facilitating a smoother authorisation process.

We can help with:

  • Exposure modelling, human health and environmental risk assessments, toxicology and ecotoxicology, environmental fate modelling expertise
  • Building biocidal product families
  • Monitoring efficacy studies to support label claims

Get in touch at to schedule an informal chat with our regulatory consultants about your pyrethrum-based products.

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