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Updates to UL 8782 – Pollution Control Units for Commercial Cooking

What you need to know about updates to UL 8782, Pollution Control Units for Commercial Cooking.


December 3, 2019

Traditional commercial kitchen exhaust systems in the U.S. generally consist of three main components:

  • Hoods (UL 710, UL Standard for Safety for Exhaust Hoods for Commercial Cooking Equipment)
  • Ducts (UL 1978, UL Standard for Safety for Grease Ducts)
  • Fans (UL 762, Outline of Investigation for Power Roof Ventilators for Restaurant Exhaust Appliances)

With the rise of mixed-use buildings, as well as current urbanization trends, there is an interest in controlling emissions from commercial kitchen exhaust systems. The products that have been designed to control the effluent and smoke from the commercial cooking process are called by many names: ecology units, air filtration units, exhaust filtration units. In order to ensure that products are evaluated correctly, UL and members of industry have determined that an appropriate terminology for these products would be pollution control units.

Pollution control units are not addressed within the scope of the referenced commercial kitchen exhaust standards. Because of the lack of requirements, there is a potential for misalignment of evaluation between different testing and certification organizations. And from the lack of clear construction and testing requirements, there could exist misunderstandings or misalignment with manufacturers and the details that code officials are looking for.

To assist manufacturers and code officials, UL has created a new UL 8782, Outline of Investigation for Pollution Control Units. The requirements in this outline cover pollution control unit assemblies that are intended to be installed in line with commercial grease ducts used to exhaust heat, smoke, and grease-laden vapors from commercial cooking operations to the outdoors as specified in the Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations (NFPA 96), the International Mechanical Code, and the Uniform Mechanical Code. The requirements include modular pollution control assemblies, unwelded connections between adjoining parts, fittings, access doors, and the like. Please note that this outline addresses the safety aspects of this appliance and does not measure the efficacy of the pollution control unit to remove grease-laden effluent from the air stream, nor other factors that do not directly affect users or electrical and fire safety.

This Outline of Investigation uses tests and safety principles from several UL Standards to address the hazards present in a commercial kitchen exhaust system. Products installed downstream of the exhaust hood are typically not in view of kitchen staff, thus increasing the potential for fire hazards. UL certifications for pollution control units previously had been evaluated using the elevated temperature flue gas tests (normal 260°C and abnormal 1,093°C). These and the other tests help ensure that during an abnormal situation, the grease duct will be equivalent to a continuously welded metal duct. The updated UL 8782  also addresses electrical requisites for the product using requirements proven suitable for kitchen environments from UL 710 and other applicable standards.

UL has established the category control number (CCN) YZHK. Additional information related to this category can be found on UL Product IQ. We are currently working with customers to help ensure they are in compliance with the new requirements by transitioning files to the new category before the April 30, 2020 due date.  Products manufactured after this date will be assessed for compliance to UL 8782.

Let UL help, contact us at to determine how we can assist you in complying with these new requirements. To learn more about this standard update, visit UL’s industry file review website.


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