Workers

The 2014 EFSA guidance also introduced transfer coefficients (TCs) for manual tasks in grapevines which were based on values derived from US Agricultural Re-entry Taskforce (ARTF) studies by the US Environmental Protection Agency (EPA). The CropLife Europe-established Bystander Resident Orchard Vineyard (BROV) research programme also involved generating a vineyard re-entry database by conducting five studies where workers in the Czech Republic, Germany, France and Italy were monitored whilst hand harvesting, pruning, training and shoot lifting in treated crops. Passive dermal exposure measurements in line with OECD Guidance and concurrent DFR measurements facilitated the calculation of TC values for multiple activities and various levels of protection, giving much more flexibility than the current guidance. These TC values are task- and not chemical-dependent and can be used generically to carry out risk assessments for all products where the grape re-entry scenarios are relevant.

Predicted worker re-entry exposure according to the EFSA guidance is directly proportional to DFR and this parameter can significantly impact the outcome of assessments for activities like harvesting, crop maintenance and crop inspection. The EFSA guidance also requires re-entry assessments for bystanders and residents who may find themselves in a treated crop. The current EFSA default DFR value is the approximate 90th percentile from a database of 55 studies and when multiplied by high estimates of transfer coefficient (TC) and dermal absorption leads to a conservative estimate of dermal exposure.

The industry holds large numbers of DFR data and CropLife Europe is interested in investigating whether the EFSA default is supported across a much larger dataset. DFR studies are seasonal, logistically challenging and expensive, so there is an appetite to interrogate the data to improve opportunities for extrapolation between studies in a way that satisfies regulatory authorities who are currently reject read across.

In an ongoing project statistical evaluation is being undertaken to investigate how parameters, such as crop, leaf type, formulation and application method can influence the magnitude of DFRs. The ultimate intention will be to publish the outcome of this meta-analysis and engage with EFSA and Member States to encourage improvements in the current re-entry exposure assessment paradigm.