Overview

Germicidal Irradiation Systems (GIS) are a vital tool in combating the viral spread of pathogens and ensuring public health s

afety. These devices are compact and have the complete protection scheme built-in for operations with no exposure to humans. However, these devices weren’t widely installed before the Covid pandemic. Consequently, NEC 2020 and previous editions didn’t address their installation requirements and specifications. NEC 2023 introduced a new Section 410.197 specifically for GIS installation requirements. This addition aims to offer clear guidelines and serve as a valuable reference for electricians installing GIS devices, improving safety and effectiveness.

Applying the 2023 Code

The COVID-19 pandemic underscored the necessity for more compact devices capable of safely emitting UV radiation to disinfect frequently touched surfaces. Two such devices are Germicidal Irradiation Luminaires and Germicidal Irradiation Systems (GIS), installed specifically to disinfect high-touch surfaces like keypads. While Germicidal Irradiation Luminaires emit UV radiation in all directions, they may lack built-in protections to shield humans from harmful exposure if operated in their vicinity. These devices lack the capability to detect human presence and activate whenever powered. Consequently, Germicidal Irradiation Systems are preferred in environments where pathogen disinfection must occur only in the absence of humans. . NEC 2023 introduced new guidelines related to the listing of GIS, sourcing of system components, installation, and use in dwelling and aimed at ensuring the safe and effective installation of these devices. The purpose of this addition is to encourage greater utilization of GIS devices for combating disease-causing pathogens.

What’s New for the 2023 NEC?

The below presents a comparison between the 2020 NEC and the 2023 NEC regarding Section 410.197.

2020 NEC

The NEC 2020 did not address the Germinal Irradiation Systems (GIS).

2023 NEC

410.197 Germicidal Irradiation Systems
(A) Listing
A germicidal irradiation system intended to provide a safeguard against UV exposure by ensuring that a building space will not be occupied during luminaire operation shall be listed and identified as a germicidal system.
(B) System Components
All system components shall be provided by the system manufacturer or clearly specified in the installation instructions as a component that the installer is required to source separately.
(C) Installation
A germicidal irradiation system shall be installed in accordance with the manufacturer’s installation instructions and installation markings.
(D) Dwellings
A germicidal irradiation system shall not be installed in a dwelling unless listed and identified for use in dwellings.