One of the most common questions restaurant owners ask is how often a kitchen hood and exhaust system should be cleaned. The answer is not a single number that applies to every restaurant. It depends on how much cooking you do, what kind of food you cook, and how much grease your operation produces. What is universal, however, is that allowing grease to build up to dangerous levels is a violation of fire code and a serious risk to your business.
This guide explains hood cleaning frequency in clear, simple language. It is written for restaurant owners and managers, not inspectors or engineers. You will learn what the California Mechanical Code actually requires, how inspection schedules work, why some systems need more frequent cleaning than others, and how to choose a schedule that protects your restaurant.
Why Hood Cleaning Frequency Matters
A commercial kitchen exhaust system removes grease, smoke, and heat from cooking operations. Every time food is cooked, grease-laden vapors rise into the hood and are pulled into the duct system. Over time, this grease sticks to interior surfaces.
If grease is allowed to accumulate, it becomes fuel. Exhaust fires move quickly through ducts and fans and can spread to the roof before anyone realizes what is happening. This is why fire codes focus heavily on how much grease is present, not simply how often a system is cleaned.
Regular hood cleaning is not just about passing inspections. It is about reducing fire risk, protecting equipment, maintaining airflow, and keeping your business open.
What the California Mechanical Code Actually Says
In Los Angeles and throughout California, hood cleaning requirements are governed by the California Mechanical Code (CMC), which adopts national standards from NFPA 96. The code does not say that systems must be cleaned monthly, quarterly, or annually in all cases. Instead, it focuses on condition.
CMC 514.4.1 states that hoods, grease removal devices, fans, ducts, and other exhaust components must be cleaned before surfaces become heavily contaminated with grease or oily sludge.
This wording is important. The law is not concerned with the calendar. It is concerned with grease buildup. If a system becomes heavily contaminated before its scheduled cleaning, it is already out of compliance.
Inspection Frequency Versus Cleaning Frequency
Another point that often causes confusion is the difference between inspection schedules and cleaning schedules. The code provides a table that outlines how often systems should be inspected for grease buildup based on cooking type and volume.
Inspection does not always mean cleaning. It means checking the system to determine whether cleaning is required. In practice, many restaurants combine inspection and cleaning into the same visit, but the distinction is important.
A low-volume kitchen may pass several inspections without needing a full cleaning, while a high-volume operation may require cleaning at every inspection.
Hood Cleaning Inspection Schedule (CMC / NFPA 96)
| Type or Volume of Cooking | Inspection Frequency |
| Solid-fuel cooking operations | Monthly |
| High-volume cooking (24-hour, charbroiling, wok cooking) | Quarterly |
| Moderate-volume cooking operations | Semiannually |
| Low-volume cooking (churches, seasonal businesses, senior centers) | Annually |
This table provides a baseline, not a guarantee of compliance. The actual condition of the system always takes priority.
Why Some Restaurants Need More Frequent Cleaning
Two restaurants can follow the same inspection schedule and still have very different cleaning needs. The difference usually comes down to grease production.
Cooking methods such as charbroiling, frying, wok cooking, and solid-fuel cooking release large amounts of grease into the exhaust system. These kitchens often require more frequent cleaning because grease accumulates rapidly.
By contrast, kitchens that do lighter cooking or operate fewer hours per day may accumulate grease more slowly. Even then, inspections are critical to confirm that buildup is not occurring in hidden areas.
What “Heavily Contaminated” Really Means
The code uses the term “heavily contaminated,” but it does not assign a specific thickness or measurement. Inspectors and professionals determine contamination based on visible grease accumulation.
If grease is thick, sticky, dripping, or pooled inside ducts or fans, the system is considered contaminated and overdue for cleaning. Even if the hood appears clean from the kitchen floor, grease inside the ductwork can still place the system out of compliance.
This is why internal inspections are essential. Surface appearance alone is not a reliable indicator of cleanliness.
The Risk of Waiting Too Long Between Cleanings
Delaying hood cleaning increases risk in several ways. First, fire risk rises as grease accumulates. Second, airflow is reduced, making kitchens hotter and smokier. Third, grease buildup accelerates wear on fans and motors.
There are also operational risks. Failed inspections can result in citations, reinspection fees, or even temporary closure until cleaning is completed. Insurance companies may also review maintenance records after an incident.
Regular cleaning based on actual system condition is far less costly than dealing with emergencies.
Why Visual Proof Matters
Many owners rely on service stickers or invoices as proof that cleaning has been done. While documentation is important, it does not show the condition of the system.
Photo documentation provides real confirmation. Seeing the inside of ducts and fan housings allows owners to know whether cleaning is thorough or superficial. If you have not seen photos of your exhaust system recently, you are relying on assumption rather than evidence.
Choosing the Right Cleaning Schedule for Your Restaurant
The safest approach is to combine scheduled inspections with condition-based cleaning. This means inspecting the system at the frequency recommended for your cooking type and cleaning it whenever grease buildup approaches unsafe levels.
This approach prevents both over-cleaning and under-cleaning. More importantly, it ensures compliance with code requirements that focus on cleanliness rather than dates.
Owner Responsibility Cannot Be Delegated
Regardless of how often your hood is cleaned, responsibility ultimately rests with the restaurant owner. If grease is found during an inspection or after a fire, the owner is held accountable.
Understanding cleaning frequency is part of managing that responsibility. Knowing when restaurant hood cleaning los angeles is needed—and verifying that it is done properly—protects your staff, your customers, and your investment.
How Bryan Exhaust Helps Restaurant Owners
Bryan Exhaust works with restaurant owners to evaluate exhaust system condition, recommend appropriate cleaning intervals, and identify problems before they become violations or hazards.
By focusing on inspection, verification, and real system condition, we help owners choose cleaning schedules that make sense for their operation.
Final Thoughts
There is no single answer to how often a restaurant hood should be cleaned. The correct frequency depends on cooking volume, grease production, and actual system condition. What never changes is the requirement to keep the system free of heavy grease buildup.
Regular inspections, timely cleaning, and clear verification are the most reliable ways to stay compliant and reduce risk. When owners understand how their exhaust system behaves, they can make informed decisions that keep their restaurant safe and operating smoothly. f
