Fenbendazole seems to be well tolerated in humans after oral exposure (single oral dose up to 2,000 mg/per person; 500 mg/per person for 10 consecutive days); however observations in humans are limited. Fenbendazole is of low acute toxicity after oral exposure. No acute exposure limit is available.Jan 15, 2014

https://www.ema.europa.eu/en/documents/variation-report/panacur-aquasol-v-c-2008-x-03-epar-assessment-report-extension_en.pdf