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The Hazard Quotient (HQ) compares field application rate to intrinsic toxicity assessed with sensitive indicator species. As a hazard indicator for risk assessment, the HQ must be calibrated against measured effects under field conditions. Because protection goals may be context specific, we analyse how choice of acceptance criteria affects setting of the HQ and calibrate HQ for various scenarios under the strict condition that no false negative conclusions may be reached. We use Non-Target Arthropod toxicity data from laboratory studies on inert (Tier 1) and on natural substrates (Tier 2) and calibrate the HQ using application rates and arthropod abundance counts from field studies in orchards, arable fields, and hay meadows in 34 locations in Western Europe. With 21 formulations (17 active substances) tested in mostly multi-rate field studies, our reference data base has 120/121 values at Tier 1/Tier 2, respectively. We use the Proportion of Affected Taxa and Duration of Effect to jointly define acceptance criteria, starting with No Observed Effects. Absence of field effects is correctly predicted with HQ