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Horticultural Lighting - Safety, Performance and Financial Incentives


March 23, 2020

By Dr. Hans Laschefski, Industry Marketing Manager, Lighting EMEA


The Market of Horticultural Lighting

LED lighting for horticulture is becoming more than a promising market niche, and today 95% of indoor growing facilities rely on solid state lighting. Horticultural growing facilities service a number of industries including indoor crop production (especially in Europe), legal medical and recreational cannabis (especially in the United States), greenhouses (50%) and indoor “vertical farms” (45%).

Luminaires and grow systems specifically designed for horticultural applications are a critical element in these innovative agricultural environments. Based on light-emitting diode (LED) technology, most of today’s advanced horticultural lighting systems are highly customizable and can provide light with color and intensity characteristics, calibrated to meet the specific growing requirements of individual plants. The better the lighting, the more efficient the plant growth process and the less costly indoor “farming” becomes.


Safety – UL 8800 First Edition Has Been Published

UL 8800, the UL Standard for Horticultural Lighting Equipment and Systems, has been issued in its first edition on August 30, 2019. It addresses the unique safety issues applicable to horticultural luminaires, lighting components and grow systems.

Key differences include:

The scope of other current safety standards for luminaires addresses safety issues for lighting equipment that is hardwired in a fixed location and designed for the purpose of general illumination. In contrast, the scope of UL 8800 specifically covers luminaires and grow systems, intended for use in the active development and growth of plants.

Environmental considerations — General environmental conditions within indoor horticultural operations can vary widely, with high humidity levels and temperature conditions. Under UL 8800, horticultural lighting systems are evaluated for their suitability in damp and/or wet environments, as well as in environments with elevated ambient temperatures. When the luminaire is exposed to excessive dust and water and is market with an ingress protection code (IEC 60598-1) it should have a minimum rating of IP 54. Lighting systems achieving UL 8800 certification bear markings that verify these characteristics.

Photobiological effects — UL 8800 addresses safety considerations associated with the photobiological effects and potential hazards associated with human eye and skin exposure to light source technology widely used in horticultural lighting systems. UL 8800 photobiological safety requirements are consistent with those found in IEC 62471, Photobiological Safety of Lamps and Lamp Systems, and provides the user with detailed information on what precautions to take regarding the potential exposure of the light output.

Wiring and connection methods - Unlike luminaires installed in conventional industrial and commercial settings that remain fixed throughout their useful life, horticultural lighting systems are typically designed to be frequently raised, lowered or repositioned in order to optimize plant growth. As such, UL 8800 allows for specialized wiring and connection methods that support the required positioning flexibility.


Performance – UL S 8000 a specification for trustable performance

Discussing the performance of a horticultural lighting systems requires the knowledge and understanding of photometrical values like photosynthetic photon flux (PPF) or photosynthetic photon flux density (PPFD), which are commonly used for such applications but unusual in general lighting. Since weighting the radiational flux with the eye sensitivity curve is useless for horticultural applications – because plants “perceive” differently – the photon flux is finally given in µmol/s. This means nothing else but a certain number of photons being emitted per time unit.

Since Feb. 22, 2019, UL S 8000 provides a specification under the UL Lighting Performance Scheme as a neutral third-party test and certification program to recognize products that meet a number of requirements for performance, reliability and suitable features for use in horticultural lighting. The test report contains detailed, useful information for growers about the provided spectrum including spectrum distribution; flux versus wavelength plot; photosynthetic photon flux density contour plot and several other metrics. From a subset of this test a performance label can be derived, and it shows a snapshot of the product performance and could ideally be used for marketing activities.

UL’s performance testing of horticultural lighting measures key light characteristics that are essential to plant growth, helping to ensure that growers have the information they need to choose an appropriate lighting system for their specific growing operation. And the UL report of performance testing of horticultural lighting meets the requirements of American Society of Agricultural and Biological Engineers (ASABE) standards, thereby facilitating qualification in accordance with the technical requirements of the DesignLights Consortium (DLC).


Financial Energy Efficiency Incentives and Local Standards Qualifications – DLC registration may be required

The DesignLights Consortium (DLC) as a not-for-profit organization, with the mission to drive efficient lighting. The DLC publishes a “Qualified Products List” (QPL) to promulgate products that meet established guidelines on light quality and energy efficiency. The QPL is searchable via and is open to everybody. Horticultural luminaires must meet UL 1598 and UL 8800 Standards, and the DLC accepts the above-mentioned UL performance tests as registration criteria for horticultural products listed within the QPL data base. But in order to also demonstrate the commitment to the safety of a product, compliance with not just UL1598 but also UL8800 was added in August 30.

The DLC QPL database provides value to both horticultural lighting manufacturers as well as their customers. Products listed have been tested to meet critical lighting safety and performance standards, confirming manufacturers’ claims while helping customers to purchase products that will meet this demanding application environment.

In addition, if the customer is located in one of the 17 U.S. states or in British Columbia, Canada where utilities currently facilitate the use of DLC listed horticultural products, they can receive an incentive award, depending on the energy savings. A win-win situation for the customer and the manufacturer.

Horti Label