One Moment!

For the optimal user experience please use Google Chrome, Firefox, or Microsoft Edge.

Thank you!

Data For Thought: Local Law 191

100% of Class B office buildings will be required to comply with LL191 by January 1, 2021. The local law has expanded the requirements for carbon monoxide detection to all Group B business occupancies that contain fuel-burning appliances. The law also includes a retroactive provision, which requires listed CO detectors to be installed in all existing buildings that are equipped with fire alarm systems and contain Group A-1, A-2, A-3, Group B, or Group M occupancies.

Where is CO detection required?

  1. Any room containing CO-producing equipment, except kitchens.
  2. Any corridor on the story where a carbon monoxide-producing equipment unit is located, as well as one story above and one story below.
  3. Any corridor on the story where enclosed parking or a loading dock is located, as well as one story above and one story below. 
  4. Any parking attendant’s office or booth located within an enclosed garage or loading dock. 

What are additional requirements to consider? 

  1. Activation of a CO detector located at the source of CO-producing equipment must shut down that source. This provision does not apply where the source is a generator.
  2. CO detectors must be installed in accordance with NFPA 720 – 2015 edition, as modified for New York City by this section.
  3. Carbon monoxide alarms and detectors need to be listed in accordance with UL 2034 and UL 2075.

Why does this matter? 

Carbon monoxide, nicknamed the ‘silent killer’ is an odorless, colorless gas that can lead to accidental poisoning and death. Office buildings with semi-enclosed spaces pose the highest risk to occupants. To make sure that CO detection system plans and specifications are properly designed and installed, NYC building code requires them to be developed by a New York State Registered Design Professional. It also matters because failing to comply with LL191 may lead to fines and/or violations from AHJ. If you'd like more information about how building owners and managers can ensure that their buildings are safe and in compliance, please reach out to our Principal, Rob Andersen at or call 646.778.5635.

Related Stories