Access panels must have fasteners that should not do what to the duct walls?

Access panels must have fasteners that do not puncture the duct walls to maintain the integrity and safety of the ventilation system. Puncturing the duct walls can lead to a number of issues, such as compromising the airflow, increasing the risk of fire due to the exposure of combustible materials, and allowing the entry of contaminants into the ducting system. The NFPA 96 standard emphasizes the importance of using hardware that allows for easy access to the maintenance and cleaning of ventilation systems without damaging them. Ensuring that the fasteners do not puncture the ducts helps in maintaining a continuous and safe environment for the commercial cooking operations, which is essential for effective performance and fire safety.