The document provides instructions for cleaning a horizontal laminar airflow hood according to USP Chapter <797> guidelines. It describes the various components of the horizontal hood and their functions in maintaining sterility. It outlines the necessary supplies, including sterile water, sterile 70% isopropyl alcohol, and lint-free wipes. It also provides a preview of the cleaning procedure, which involves first using sterile water to remove any residue, followed by sterile 70% isopropyl alcohol as the primary disinfectant. Upon completion, the technician must document the cleaning on the hood-cleaning checklist.