If the weight-of-the-evidence analysis indicates that the substance has the potential to cause pain, or initial testing shows that a painful reaction will occur, a local anaesthetic may be used prior to instillation of the test substance.
Hvis weight-of-the-evidence-analysen viser, at stoffet har smertevoldende potentiale, eller hvis den indledende testning viser, at der vil komme en smertefuld reaktion, kan der bruges et lokalanæstetikum før instillation af teststoffet.