UL Issues Recommended Practice and Design Guideline for Circadian Stimulus

LDS 9 CS circadian rhythm 400

April 29, 2019

UL has created a recommended practice and design guideline for those wanting to support circadian entrainment in buildings, according to Edison Report. The design guide went out for public comment last month. The Task Group was chaired by Dr. Mark Rea, of the Lighting Research Center.

The document is intended for use by those who design and specify lighting in buildings and wish to provide light for vision and for circadian entrainment for typical day-active people and night-inactive people. The document provides a simple way of implementing circadian-effective light and a method for verification of effect on building occupants.

The recommended practice states, “The amount of light equivalent to that, after one hour of exposure, capable of suppressing the production of melatonin at night by 30% (CS=0.30) should be continuously available at the occupant’s eyes for a minimum of two hours during the daytime. In simple terms, this translates into a vertical illuminance at the eye (EV) of about 350 lx for warm sources and about 200 lx for cool sources, but the exact amount depends upon the spectral power distribution of the light source.

Source: Edison Report: edisonreport.com/ul-issues-recommended-practice-and-design-guideline-for-circadian-stimulus/

Related Articles


Changing Scene

  • July 10, 2025 - Mac’s II Agencies Announce Addition to Project & Specification Sales Team

    Mac’s II Agencies Announces Addition to Project & Specification Sales Team

    Mac’s II Agencies is pleased to announce that Drazen Jerkovic will be joining their Project & Specification Sales team in the Lighting Division later this fall. With over 25 years of experience in the lighting and electrical industry, Drazen is a highly respected consultant known for his technical knowledge and deep understanding of project delivery. His recent role… Read More…

  • Noramco-Announces-Samantha-Boernsen-as-New-Regional-Sales-Manager-Winnipeg

    Noramco Announces Samantha Boernsen as New Regional Sales Manager, Winnipeg

    Please join Noramco in welcoming Samantha Boernsen as Regional Sales Manager, Winnipeg! Samantha brings a wealth of experience in the electrical industry, with a strong focus on lighting, marketing strategy, and customer engagement. She has built her career on connecting technical expertise with real-world application, making her a trusted partner to clients and colleagues alike.… Read More…


Design

  • Infrastructure Lighting Fixtures: Why Scale Matters

    Infrastructure Lighting Fixtures: Why Scale Matters

    In infrastructure projects, the size and scale of outdoor lighting fixtures are critical—not just for aesthetics, but for functionality, safety, and long-term performance. Whether lighting a streetscape, transit hub, or civic plaza, appropriately scaled fixtures help create environments that are both visually coherent and effectively illuminated. Public lighting plays a role in shaping how spaces… Read More…

  • What You Need to Consider When Choosing Data Center Lighting

    What You Need to Consider When Choosing Data Center Lighting

    When operating a data center, the lighting syst​em is often not the most concerned part. Actually, lighting system performance directly influences whole electricity consumption and operating costs, especially in a 24-hour non-stop data center. This article will delve into the key factors to be considered when choosing data center lighting. For enterprises that are planning to… Read More…


New Products

  • SATCO|NUVO: LED T12 Lamps

    SATCO|NUVO: LED T12 Lamps

    SATCO|NUVO’s LED T12 ballast compatible lamps are direct replacements for T12 linear fluorescent. Offered in a frosted white finish, these lamps are also PET coated and NSF rated. Conveniently sold in two-packs, these lamps make replacing traditional tubes an easy choice. Suggested applications include shop light fixtures, laundry room, utility closets, and garages. Read More…

  • BOLD: Prism Recessed Outdoor Fixture – RL-PRISM-60-BK

    BOLD: Prism Recessed Outdoor Fixture – RL-PRISM-60-BK

    The Prism is part of BOLD’s high-end, durable, and modern 60mm (2 3/8″) recessed fixtures. With its 93 CRI, hexagonal design, partially covered light source, and 360-degree warm glow, you can create unique ambient lighting effects and modern designs, minus the glare. You can safely walk or drive over these raised recessed lights: their low-profile… Read More…