How often do interior kitchen duct cleaning requirements typically apply according to NFPA 96, with consideration for heavy grease loads?

How often do interior kitchen duct cleaning requirements typically apply according to NFPA 96, with consideration for heavy grease loads?

• A. Typically every 6 to 12 months, with more frequent cleaning for heavy grease loads and additional annual inspections.
• B. Every 24 months.
• C. Weekly cleaning.
• D. Only when there is visible grease.

Answer: (D)