Solid-Fuel Cooking: Monthly Inspection and Ash Handling

What this covers

Cooking over wood, charcoal, or another solid fuel is treated separately in NFPA 96. It is not a stricter version of the ordinary hood rules. It is an additional chapter (Chapter 15, Solid Fuel Cooking Operations) with its own equipment and housekeeping requirements, and it changes how often the exhaust system must be inspected.

This applies if any part of the cooking line burns solid fuel: a wood-fired pizza oven, a charcoal grill or robata, a smoker. It applies even when the rest of the line is gas or electric.

Inspection moves to monthly

Under NFPA 96 Table 12.4, a system serving solid-fuel cooking equipment is inspected monthly.¹ That is the shortest interval in the table, shorter than the quarterly interval for 24-hour, charbroiling and wok operations.

The reason is what accumulates. Solid fuel deposits creosote and ash on top of ordinary grease, and creosote ignites at temperatures the system is already reaching.

Monthly is the inspection interval, not an automatic monthly cleaning. Cleaning happens when an inspection finds accumulation that has to come out. See Exhaust-System Inspection and Cleaning for how the two differ.

Equipment requirements that are specific to solid fuel

NFPA 96 Chapter 15 covers the hood, exhaust, grease removal, air movement and fire-extinguishing equipment for solid-fuel operations. In practice the provisions an operator runs into are:

• A separate exhaust system. Solid-fuel cooking equipment is generally required to exhaust through its own system rather than share a duct with gas or electric equipment. There are limited exceptions, so this is a question for your designer and your fire code official, not something to assume either way.
• Spark arresters. Where the operation can throw airborne sparks and embers, spark arrester devices go ahead of the grease removal device so sparks do not reach the filters, hood and duct.
• Grease removal devices rated for solid fuel. They must be steel or stainless steel, or otherwise approved for solid-fuel cooking. Aluminum mesh filters are not.

Fuel storage and ash removal

NFPA 96 section 15.9 sets minimum safety requirements for fuel storage, handling and ash removal. The requirement operators most often miss is that fuel must not be stored in the path used to remove ash. Ash and embers leave the kitchen in a metal container, kept away from combustibles until the contents are cold.

Build ash removal into the closing routine rather than leaving it to whoever notices. A container of live embers left against a wall is one of the few ways a compliant kitchen still burns down.

What to keep

• The monthly inspection report from your hood contractor, showing the date and what was found.
• Cleaning reports for any cleaning the inspection triggered.
• Anything your fire code official issued about the separate exhaust system or spark arresters at plan review.

Your local fire code official (the authority having jurisdiction) enforces the edition of NFPA 96 your jurisdiction has adopted, and may set requirements beyond it. Editions differ: the inspection table is Table 12.4 in the 2021 and 2024 editions and Table 11.4 in 2017. Confirm which edition applies to you before relying on a section number. Official standard: https://www.nfpa.org

Sources for the specific figures above

1. NFPA 96 section 12.4 (model baseline: we have no adoption on record for your jurisdiction)