Science articles

Exposure and risk assessment for coformulants (Part 3)An urgent need detected

Following the post published on 29/05/24, we continue with the summary of the items discussed by the EFSA and European Commission’s staff related to the assessment of coformulants in PPP:
The current practices to assess PPPs are usually based on hazard: SDS, classification is checked (if the co-formulant is classified, its concentration in the PPP is verified whether it would trigger the classification of the PPP), CMR status (if CMR category 1 or 2 in some countries, the assessment is stopped). In few cases, genotoxicity studies on the PPP have been required. If no hazard identified, no exposure assessment would be needed.
The full composition of the PPP is asked to the applicant, who does not always have the information mostly in case when a co-formulant is a mixture. Therefore, the supplier of the mixture should provide the requested information.
It has been raised the lack of exposure data to perform a risk assessment while it is acknowledged by some MSs that the hazard-based approach may not be sufficient because a toxicological risk assessment is not systematically performed for the co-formulants. The biocide approach was also mentioned as an option to investigate, based on the ‘substance of concern (SoC)’ approach. Existing scientific information including monitoring data regarding exposure of humans and the environment should assist in the assessment. It can be literature or monitoring data. However, uncertainties are associated with the identification of co-formulants or sometimes only the active substance is traceable and it may be difficult to identify the source of exposure. For non-dietary exposure, the exposure and risk assessment would be based on the concentration of the co-formulant in the PPP.
The potential concerned linked to toxicokinetic interaction has been raised by a MS and QSAR data should be provided for the assessment.
For dietary exposure, the question about the amount of the co-formulant still present on the food has been raised and is difficult to extrapolate from the concentration in the PPP. There is an ongoing work in one MS to get real data for some co-formulants, but it is still at an early stage. Some MSs indicated that field data on the co-formulant may be retrieved from the literature or may be requested in theory with the PPP in some cases e.g., based on the type of the formulation.
The phys-chem properties of the co-formulant may help to understand how the co-formulant is transformed. However, the specific environmental conditions (e.g. light, heat…) should be known to better anticipate the stability for instance, of the co-formulant.
For environment exposure of individual co-formulants, it would depend on the scenario, and it is essential to know which parameters to be indicated in the model to get a reliable output. ECHA may be a source for data (in case of high tonnage).
There are uncertainties for ecotox risk assessment, if no reliable data are coming from modelling data. It was also mentioned that some function of co-formulants e.g. wetting agent, may be of potential concern for certain non-target organisms due to a physical effect. Finally, poisoning data for at least acute toxicity or data related to accidental exposure for environment have been discussed as a potential source of data. It is acknowledged that many uncertainties are associated to this information as declarative information, but still may be considered as an indicator. Wildlife poisoning investigations are likely only to focus on active substances but in the case an ancident is linked to the use of a PPP it could be considered as to whether the incident was a result of the active substance or the product.

Proposals for initial criteria to build a list of co-formulants categorised as no concern.
Risk assessment not needed if, e.g.
?No/low Hazard
?Cut off criteria for unacceptable co-formulants e.g., Classification CMR cat. 1
?No exposure for specific area (e.g., ornamental uses for dietary exposure)
?Low exposure based on GAP (threshold to be defined)
?Existing RMM ensure safety of the PPP on case-by- case approach? i.e., safety sentences
?Regulated in other EU frameworks case by case e.g., feed/food additives
When is the risk assessment of the co-formulant/PPP needed?
?When there is a potential concern not only from classification but e.g., derived no effect level (DNEL) available identified during the hazard assessment of the coformulant
?When there is exposure
?Critical function of co-formulants could be identified, e.g. wetting agents, emulsifier, preservatives (biocides) may be relevant for ecotox aspects as NTO could be close to target pest.
?PPP more toxic than the a.s. based on hazard (e.g., metabolic biomarkers, classification, adversity of the effects)
?Potential for toxicokinetic interaction (test the PPP or produce toxicokinetic data as ‘longer term’ proposal)
?Follow the current biocide and pesticide approach i.e. looking at the classified component and triggering the classification of the PPP
?Use phys-chem properties e.g., LogPow, stability/persistence to be combined with exposure potential (e.g. availability of the co-formulant) to understand whether there is a need or not to perform a risk assessment
?Environmental exposure: tool exists but some adjustments are needed/confidence on the parameters -> e.g. use uncertainty factors, identification of threshold…
In order to address these points, further data on the PPP will be required as well as the investigation about which co-formulant is triggering the toxicity.
(to be continued, last Part 4)