Expert opinion on the dermal absorption of a plant protection product active ingredient


The client manufactures a plant protection product (PPP) containing two active ingredients; both suspension concentrate and dilute preparations are marketed. The default dermal absorption value for an active ingredient is based on the concentration; on this basis a value of 75% was indicated for the two substances in question. Bibra was supplied with an in vitro dermal absorption study on one of the active ingredients which suggested the potential might be somewhat lower. The client had an urgent need for an expert opinion for submission to the relevant competent authority.


A manufacturer of plant protection products (PPPs).

Project goals

Bibra was asked to provide an expert opinion on the dermal absorption potential of one of the active ingredients, to justify the use of a non-default value in a specified exposure scenario as part of a human health risk assessment of the PPP.


Bibra evaluated the submitted in vitro study and summarised relevant data from an EFSA opinion on the active ingredient. A weight of evidence conclusion was provided to justify using a lower than default absorption figure.

Project outcome

With particular reference to the in vitro dermal absorption study using human skin, and noting the absorption values proposed by EFSA, bibra concluded that a reasonably conservative dermal absorption value of 5% could be supported and this figure was proposed for the regulatory submission. Bibra provided the expert report both under budget and within the tight timeframe.

Bibra project team

Daniel Threlfall

Pete Watts


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