Interior surfaces of the exhaust system shall be accessible for cleaning and inspection purposes. [NFPA 96:4.1.8] View this post on Instagram CMC 507.1 Exhaust Systems (5) Interior surfaces of the exhaust system shall be accessible for cleaning and inspection purposes [NFPA 96:4.1.9] A post shared by Bryan Exhaust Service (@bryanexhaustservice) on Sep 19, 2019 at 12:21pm PDT