1
Grade 1 — Light
Recently serviced · COMPLIANT
Thin film of grease under 1/32" (0.8mm). Surfaces appear clean or lightly coated. Baffle filters show minimal buildup. No pooling or dripping. Action: Document and schedule next cleaning per frequency requirement.
Thin film onlyNo poolingFilters clean
2
Grade 2 — Moderate
Cleaning needed soon · MONITOR
Buildup 1/32" to 1/8" (0.8–3mm). Visible coating on baffles, plenum walls, duct interior. Some hardened deposits. Possible light dripping at filter seams. Action: Schedule cleaning within 30 days.
Up to 1/8" thickVisible coatingSome hardening
3
Grade 3 — Heavy
Immediate cleaning required · NON-COMPLIANT
Buildup exceeds 1/8" (3mm). Thick deposits on all surfaces. Active dripping at filter seams. Baffles may be partially blocked. Possible charring or carbonization. Action: Immediate service. Notify customer of NON-COMPLIANT status in writing.
Over 1/8" thickActive drippingDuct blocked
4
Grade 4 — Extreme
Fire hazard · SHUT DOWN RISK
Severe accumulation throughout. Duct significantly obstructed. Evidence of previous grease fires. Suppression nozzles may be coated or blocked. Immediate fire hazard. Action: Stop cooking if safe. Emergency service. Report to AHJ.
Fire hazardDuct obstructedSuppression risk
§ 11.4
Grease Removal Devices
Filters must be cleaned or replaced when grease accumulation exceeds 1/8".
§ 11.7
Exhaust Ducts
Inspection frequency: monthly (high-volume), quarterly (moderate), annually (low-volume).
§ 10.2
Fire Suppression Systems
Nozzles must be inspected at every cleaning. Caps or covers must be intact and correctly aimed.
§ 4.1
Cooking Equipment
Equipment must be installed and maintained per manufacturer instructions. Positioning relative to hood is critical.