February 24, 2020
Authored by: Ed Joseph, UL Principal Engineer, Lighting
Indoor grow facilities are being established across North America at a rapid pace as growers of food producing plants and cannabis transition from conventional farming methods to controlled environment agriculture, also known as indoor farming. The transition to controlled environment agriculture presents new challenges to those called upon to inspect, approve and sign off on these indoor grow facilities so they can open their doors to conduct business.
Appropriately, new safety standards are emerging for equipment used in grow facilities to support the safety interests of growers, equipment manufacturers, and the inspection and regulatory community. One of these standards is UL 8800, the Standard for Safety of Horticultural Lighting Equipment. UL 8800 was published by Underwriters Laboratories Inc., a Standard Development Organization (SDO). Using its Collaborative Standards Development System (CSDS), the standard was developed under the auspices of a Standard Technical Panel (STP) consisting of individuals representing a balance of interests, who develop UL Standards for Safety by consensus. For more information on UL Standards development, visit: https://ulstandards.ul.com/.
UL 8800 was published in August 2019 and addresses safety requirements for horticultural lighting equipment intended for installation in both the United States and Canada.
This article discusses the framework of UL 8800 and the safety considerations it addresses for horticultural lighting equipment given their specialized installation and use for growing plants. Lighting equipment used to grow plants Certified to UL 8800 are evaluated for safety and code compliance given the particular needs of the grow facility.
Lastly, this article will provide information about a new section added into the 2020 Edition of the US National Electrical Code – NFPA 70, which includes installation requirements for horticultural lighting equipment.
About UL 8800
Unlike general lighting equipment which produces white light intended to illuminate people-occupied spaces, lighting equipment intended for growing plants is designed to replicate specific wavelengths of light produced by the sun that are important to optimize plant growth. These light sources often result in a purple hue, which can be potentially harmful to people entering or working in the grow facility. In addition to having a different light output characteristic, horticultural lighting equipment often has other design features specifically designed for the grow environment. The UL 8800 Standard has a targeted scope that addresses the unique safety issues associated with horticultural luminaires and horticultural lighting systems.
Here is a brief summary of several key safety requirements contained in UL 8800:
- Wiring and connection methods –Horticultural luminaires are typically designed to be frequently raised, lowered or repositioned as plants grow. UL 8800 addresses requirements for specialized wiring and connection methods that support positioning flexibility within a grow facility.
- Environmental conditions – General environmental conditions within indoor agricultural operations can vary widely, with high humidity levels and temperature conditions. UL 8800 requires horticultural luminaires to have either a damp or wet environmental rating only, and, includes provisions for testing to increased ambient temperatures. Lighting equipment achieving UL 8800 Certification bear markings that verify these characteristics.
- Ingress protection – Equipment used in indoor agricultural operations are also at greater risk of infiltration from dust, moisture and water that can compromise their reliability. UL 8800 addresses these risks with ingress protection (IP) testing that classifies and rates the degree of protection afforded by the equipment against both solid objects and water.
- Photobiological effects – UL 8800 addresses safety considerations associated with the photobiological effects and potential hazards associated with human eye and skin exposure to light sources technology widely used in horticultural lighting equipment. UL 8800 photobiological safety requirements are consistent with those found in IEC 62471, the Standard for Photobiological Safety of Lamps and Lamp Systems, and provides the user with detailed information on the necessary precautions regarding potential exposure to the light output.
- UV exposure of polymeric materials – In some grow environments, polymeric materials used in equipment can be exposed to UV from the sun such as within a greenhouse. This exposure can cause polymeric materials to become brittle and more susceptible to breakage resulting in a potentially hazardous condition. UL 8800 sets forth requirements to address this concern.
- Horticultural systems – In addition to the safety requirements for horticultural luminaires, UL 8800 includes a Part 2 set of requirements for horticultural systems. A horticultural system is defined as a prefabricated chamber, cabinet or open-frame structure identified for the purpose of growing plants and outfitted with electrical infrastructure for the active optimization of plant growth. These systems may incorporate pre-installed materials and equipment which, after installation, may be concealed and may not be accessible for inspection at the final installation site. They may additionally include lighting, shutters, controls, control panels, plumbing components such as pump motors, solenoid valves, water reservoirs, and cooling and heating components as part of the plant growth management control horticultural system. A horticultural system may include hydroponic, aeroponic, aquaponic and other forms of irrigation methods. Passive growing structures such as greenhouses or tent like coverings are not considered horticultural lighting structures in the context of the UL 8800 Standard.
Horticultural Lighting References in the 2020 National Electrical Code, NFPA 70
A new Part XVI – Special Provisions for Horticultural Lighting Equipment was added to Article 410 of the National Electrical Code (NEC©), NFPA 70, during the 2020 code cycle and is now in the 2020 edition of the NEC©. These installation requirements for horticultural lighting equipment require equipment to be listed and are coordinated with the requirements of the UL 8800 Standard. Conventional lighting products are designed for conventional area lighting needs, so it is important to require the use of lighting equipment Certified to UL 8800 for use in grow facilities.
Advantages of UL 8800 Horticultural Lighting Equipment Certification
The failure of a horticultural lighting equipment design to address the safety criteria in UL 8800 can compromise the safety of the grow facility and workers in it and can have significant consequences for indoor horticultural operations. Lighting equipment Certified to UL 8800 provides growers, workers, and members of the regulatory and inspection community confidence that the equipment will provide a necessary level of safety for a grow facility.
UL Product Categories for Horticultural Luminaires
When searching in UL’s Product iQ™ database, please refer to the product categories for Horticultural Luminaires (IFAU) and Horticultural Lighting Systems (HRTI).