How Often Do I Need to Have My Restaurant Kitchen Hood Exhaust System Cleaned?

Most restaurant fires originate on cooking appliances and spread into the kitchen's exhaust system, according to the National Fire Protection Association (NFPA). If the exhaust system is full of grease, that's fuel for the fire.

Having your kitchen exhaust system inspected and cleaned is not only a good idea; it's required by law. The NFPA mandates regular inspections and cleanings, as do state and local fire codes. Inspection frequency, as described by NFPA guidelines, must be:

• Monthly for systems serving solid fuel cooking operations
• Quarterly for systems serving high-volume cooking operations such as 24-hour cooking, charbroiling or wok cooking
• Semiannually for systems serving moderate-volume cooking operations
• Annually for systems serving low-volume cooking operations, such as churches, day camps, seasonal businesses or senior centers

The inspection must include an examination of the entire exhaust system for grease buildup, and it must be performed by a someone who is properly trained and qualified. Most cities and towns require an official certification. A valid certification of inspection must always be kept on the premises to present to fire inspectors as requested.

The NFPA does not directly mandate the frequency of cleaning; that depends on the results of the inspection and local requirements. If the inspector deems that the system is contaminated with grease, a professional cleaning is required by a certified professional. After the cleaning, a certificate showing the date of the cleaning and the areas cleaned must be kept on hand. In some cases, only a portion of the system requires cleaning.

Inspectors use guidelines created by the International Kitchen Exhaust Cleaning Association (IKECA) to determine whether a cleaning is required. They measure the grease for depths ranging from zero to 0.125 inches, according to IKECA. Inspectors give one of four inspection grades: no grease buildup; acceptable grease buildup; cleaning required; and critical depth.

Costs and Methods of Kitchen Exhaust Cleaning

Most professional cleaning services charge an hourly rate ranging from $75-$150. The rate depends on factors like the condition of the exhaust system, the size of the cleaning crew (larger crews get the work done faster) and your geographic location.

There are three methods of exhaust system cleaning: manual scraping, pressure washing or steam cleaning. Scraping is less expensive, and it can be effective when done properly. But pressure washing and steam cleaning are preferred by the NFPA.

In some cases, a cleaning service will do a combination of both. Some of the duct-work may be difficult to access, which makes scraping impossible.