Hood Cleaning & Inspection
NFPA 96 §11.4 Compliance

Why Hood Cleaning Matters

Grease accumulation inside commercial kitchen exhaust systems is one of the leading causes of restaurant fires in the United States. The National Fire Protection Association estimates that cooking equipment is involved in nearly half of all reported structure fires in eating and drinking establishments, and a significant portion of those fires involve ignition of grease deposits in the hood, duct, or fan. Regular cleaning of the entire exhaust system — from the hood interior through the ductwork to the rooftop fan — is the primary defense against these fires NFPA 96, §11.4.

NFPA 96 mandates cleaning on a schedule driven by the type and volume of cooking. The standard provides a frequency table that serves as the minimum baseline; the AHJ may require more frequent cleaning based on observed conditions.

The NFPA 96 Frequency Table

NFPA 96 §11.4 provides the following cleaning frequency schedule based on the type of cooking operation:

These frequencies are minimums. Upon inspection, if grease buildup is heavier than expected for the scheduled interval, the cleaning frequency must be increased. Conversely, the AHJ does not permit extending the interval beyond annual regardless of conditions NFPA 96, §11.4.

What Gets Cleaned

A proper hood cleaning encompasses the entire exhaust path from the hood interior to the point of discharge at the rooftop fan. Cleaning only the visible hood surface is insufficient and does not meet the NFPA 96 requirement. The full scope includes:

Hood interior: All interior surfaces of the hood canopy, including the plenum area behind the grease filters. Grease accumulates on these surfaces and can drip onto the cooking equipment if not cleaned.

Grease filters: Baffle filters are removed, soaked, degreased, and reinstalled. Damaged or worn filters must be replaced.

Ductwork: Every inch of the exhaust duct, from the hood collar to the fan, must be scraped and cleaned. This is the most labor-intensive part of the job and requires access through the duct access panels required by NFPA 96 §7.4. In older buildings where access panels were never installed, they must be added.

Exhaust fan: The rooftop upblast fan is tipped on its hinge, and the fan blades, housing, and grease containment curb are cleaned. Grease overflow from the fan containment curb onto the roof is a common fire code violation.

Grease cups and gutters: All drip trays, grease cups, and gutter systems must be emptied and cleaned NFPA 96, §11.4.1.

Who Can Perform the Cleaning

NFPA 96 requires that hood and duct cleaning be performed by properly trained, qualified, and certified individuals or companies NFPA 96, §11.4.2. In practice, this means:

IKECA certification: The International Kitchen Exhaust Cleaning Association (IKECA) provides the industry-standard certification for hood cleaning contractors. While NFPA 96 does not mandate IKECA certification by name, many AHJs accept it as evidence of qualification.

Documentation: The cleaning contractor must provide a written report or certificate after each cleaning that includes the date, areas cleaned, observations about system condition, and before/after photographs if required by the AHJ. This documentation must be retained on premises and available for inspection.

Insurance: Most jurisdictions require hood cleaning contractors to carry general liability insurance and, in some cases, pollution liability insurance (because of the chemical cleaning agents and waste grease produced).

Inspection After Cleaning

NFPA 96 §11.6 requires that after cleaning, the system be inspected to verify:

Bare metal standard: All interior surfaces should be cleaned to bare metal. A light residue is acceptable in areas that are difficult to access, but visible grease deposits indicate incomplete cleaning.

Structural integrity: The cleaning process should not have damaged seams, access panels, or the duct itself. Any damage found must be repaired before returning the system to service.

Access panel reinstallation: All access panels must be properly reinstalled and sealed. A missing or unsealed access panel allows grease-laden air to leak into the building structure.

Fan operation: The exhaust fan must be tested after cleaning to verify it operates correctly and the fan hinge is properly secured.

Suppression system check: The fire suppression system should be visually inspected after cleaning to confirm that nozzle caps, fusible links, and piping were not disturbed during the cleaning process. If any components were removed for cleaning access, they must be properly reinstalled NFPA 96, §11.6.1.

Common Deficiencies

Overdue cleaning: The most common deficiency. The service sticker on the hood is expired or missing, and grease deposits are visible inside the hood and at duct access points.

Incomplete cleaning: The hood interior is clean, but the duct and fan were not cleaned. This typically occurs when the facility hires an unqualified contractor who cleans only the visible surfaces.

Missing access panels: Duct access panels were never installed, making it physically impossible to clean the duct interior. The contractor notes the deficiency but the facility never addresses it.

Roof grease overflow: The exhaust fan grease containment curb overflows onto the roof membrane, creating a fire hazard and potential roof damage. The curb must be emptied during each cleaning.

No documentation: The restaurant cannot produce cleaning records for the current or previous year. Without documentation, the AHJ must assume the system has not been cleaned.

Practical Inspection Tips

Check the sticker: Look for the cleaning contractor’s service sticker on the hood. It should show the date, company name, and next service date. If it is expired, issue a finding.

Run a finger test: With a gloved hand, swipe the inside of the hood plenum above the filters. If your glove comes back with heavy grease, the hood needs cleaning regardless of what the sticker says.

Climb to the roof: Inspect the exhaust fan. Is there grease on the roof? Is the containment curb overflowing? Can the fan be tipped for cleaning? These are quick visual checks that reveal the true maintenance state.

Ask for records: Request the cleaning reports for the past 12 months. A properly maintained system will have documentation for each scheduled cleaning with observations noted.

Photograph deficiencies: Grease buildup is visual. Before-and-after photographs from the cleaning contractor and your own photos of current conditions create an objective record for enforcement or follow-up.

References