Restaurant Grease Filters

Most restaurants have their kitchen exhaust systems (aka hoods) cleaned every 3, 6, or 12 months to remove the grease from the entire system. Your hood cleaners are responsible to meet the requirements of NFPA 96 - Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations. Chapter 12 (2021 Ed) provides the standards and guidelines

for the inspection and cleaning of the kitchen exhaust systems. When they complete their job, they issue a certification of services performed and report whether there are deficiencies in your system. That certification tag on the hood expires after a certain period of time depending on the marked tag. Many restaurants allow their filters to build up through the months until their hood cleaners come in and then have that company clean them. The problem with that is that the filters are way past a fire-ready point after months of neglect. Grease filters act as your first line of defense in a fire and should prevent flames from passing outside of the protection zone of your fire suppression system (second line of defense in a fire).

But why should we need filters cleaned/ exchanged more regularly if our hood cleaners have been doing this for years?

NFPA 96, 4.1.5 The responsibility for inspection, testing, maintenance, and cleanliness of the ventilation control and fire protection of the commercial cooking operations, including cooking appliances, shall ultimately be that of the owner of the system, provided that this responsibility has not been transferred in written form to a management company, tenant, or other party.

Unless the responsibility is transferred to a third-party company for maintaining cleanliness of the filters (more on that below), the responsibility ultimately falls on the owner or tenant to ensure the

fire-readiness of those filters.

Either way, every filter should be cleaned at a minimum of once per week if doing the work

in-house. The primary reason is because grease filters are harder to clean the longer they are subjected to constant heat and continuing accumulation. If you use a filter exchange company, depending on their process of cleaning, they can often go longer between cleanings because their cleaning system should allow for 100% cleaning even on fairly dirty filters.

NFPA 96, 12.6.1.1.1 Hoods, grease removal devices...shall be cleaned to remove combustible contaminants to a minimum of 0.002 in. [50 microns]

Whichever route you go on maintaining your filters, make sure that airflow is not adversely affected between cleaning intervals. When they are cleaned, they have to be completely clean - down to 2/1000ths of an inch. That likely means that if you’re performing this in-house, a quick spray down will not be enough. They will need to be soaked and then sprayed thoroughly.

Absolutely NOT. This is against the law in every municipality, every state, and across the entire country. Even with using chemicals to clean them, it’s still illegal. Fats, oils, and grease (FOG) are classified as conventional pollutants under the Clean Water Act, Section 304(a)(4) and 44FR44501. Keep in mind, all storm drains eventually feed to streams, rivers, lakes, and oceans - so even if you don’t see the

damage, it can and will harm the environment downstream. Local jurisdictions will have specific laws about wastewater and storm drain discharge, so reach out to your local municipality for the specific applicable laws and regulations in your own area.

From the EPA: Stormwater runoff is generated from rain and snowmelt events that flow over land or impervious surfaces, such as paved streets, parking lots, and building rooftops, and does not soak into the ground. The runoff picks up pollutants like trash, chemicals, oils, and dirt/sediment that can harm our rivers, streams, lakes, and coastal waters. To protect these resources, communities, construction companies, industries, and others, use stormwater controls, known as best management practices (BMPs). These BMPs filter out pollutants and/or prevent pollution by controlling it at its source.

The NPDES (National Pollutant Discharge Elimination System) stormwater program regulates some stormwater discharges from three potential sources: municipal separate storm sewer systems (MS4s), construction activities, and industrial activities.

Operators of these sources might be required to obtain an NPDES permit before they can discharge stormwater. This permitting mechanism is designed to prevent stormwater runoff from washing harmful pollutants into local surface waters.

Shayne Buckley, President of FilterShine Front Range (based out of Colorado) is an industry leader in kitchen exhaust systems, code and standards compliance, along with deficiency correction with over 18 years of field and operations experience.