Horticultural Technical Requirements

Testing Lab Requirements

DLC applications require test results that are issued from an accredited laboratory. Product testing must be conducted at an accredited laboratory appropriate for the performance being evaluated. Additionally, LM-80 test results will only be accepted from laboratories listed as EPA-Recognized Laboratories for LM-80. These tests include:

  • In-situ Temperature Measurement Tests (ISTMT)
  • IES-LM-79-19 Approved Method: Electrical and Photometric Measurements of Solid-State Lighting Products
  • ANSI/IES LM-80-15 IES Approved Method: Measuring Luminous Flux and Color Maintenance of LED Packages, Arrays and Modules is preferred (IES-LM-80-08 and its Addendum A also accepted)
  • IES-LM-84-14 Approved Method: Measuring Luminous Flux and Color Maintenance of LED Lamps, Light Engines, and Luminaires.

For each of these test methods, laboratories must be approved or accredited by organizations that can ascertain appropriate testing conditions, testing equipment, and staff competencies necessary for accurate measurements.

In situ Temperature Measurement Test (ISTMT)

The DLC will accept ISTMT results from laboratories meeting at least one of the following requirements:

  • Approved by OSHA as Nationally Recognized Testing Laboratories (NRTLs). View a list of OSHA NRTLs.
  • Approved through an OSHA NRTL data acceptance program or OSHA Satellite Notification and Acceptance Program (SNAP).
  • Accredited for ANSI/UL 1598 or CSA C22.2 No. 250.0-08, including Sections 19.7, 19.10-16, by an accreditation organization that is an ILAC-MRA Signatory.

These requirements are applicable for laboratories conducting both LED ISTMTs and Driver ISTMTs.

UL 1598 testing may be used for the ISTMT report if the lab that conducted the test meets the DLC’s laboratory requirements for ISTMT.


The DLC will accept LM-79 (ANSI/IES LM-79-19) results from laboratories that comply with the DLC LM-79 Testing Lab Requirements. Testing must be conducted and reports must be issued within the accreditation effective and expiration dates detailed for a given laboratory. 

The following are acceptable accreditation organizations for LM-79 testing labs:

The below lab list references labs that have submitted approved accreditation documents to DLC and meet the DLC’s LM-79 Testing Lab Requirements. Labs are removed from this list when the accreditation info approved by DLC has expired.

Accredited labs can be added to this list by providing updated certification documents to DLC for review. These documents can be sent to horticulture@designlights.org or can be submitted with applications.

More information regarding acceptable accreditation bodies, including how additional organizations can be added to the list above, is available in the DLC’s LM-79 Testing Lab Requirements.


The DLC will accept LM-80 results from laboratories listed as EPA-Recognized Laboratories for LM-80 at the time of initial application review.

Note: DLC refers to ENERGY STAR® Requirements for the Use of LM-80 Data when determining applicability of LM-80 data for submitted products.

Information on EPA-recognized laboratories for lighting products can be found here. Laboratories approved for testing can be found here, by searching for labs recognized to conduct testing for lamps and luminaires. Labs can be contacted directly to inquire if their scope includes LM-80 testing. For questions about DLC acceptance of test data from a particular lab, please contact horticulture@designlights.org


The DLC testing requirements may include LM-84 if choosing to test through that path instead of LM-80. Additional details can be found in the Horticultural V2.1 Technical Requirements. DLC will accept LM-84 results from laboratories that meet both of the following:

  • Included in the list of DLC-approved LM-79 laboratories (provided in the link above).
  • Accredited for LM-84-14 by an accreditation body recognized by DLC (see list in LM-79 section above).

For questions, or to be included in the relevant lists, please contact horticulture@designlights.org.

Due to the length of this type of testing, it is recommended that the submitter reach out to horticulture@designlights.org to ensure the testing will align with DLC Testing and Reporting Requirements before beginning any testing using the LM-84 method.

Testing Guidance

Photos/Schematics and Tc Locations: 

Photographs and schematic diagrams indicating the Temperature Measurement Point (TMP) are required in each application. Providing clear photos in reports prevents delays in application processing

During the temperature testing of a luminaire, photos should be supplied in the ISTMT that represent the internal attachment locations of the:

  • Worst case (hottest) LED (TMPLED)
    • TMPLED measurements should be measured per LM-80/LM-84 report
    • A clear photo representing the TMPLED location tested should be provided
      • The Lumen Maintenance section has additional guidance on LM-80 Testing requirements.
      • See LM-80 and LM-84 standards for complete requirements.
  • Driver TMP (TMPps)

The schematic diagrams are used to verify that the TMP measured in the ISTMT conforms to the LED manufacturer-specified TMP location, and driver manufacturer-specified TMPps location (for Premium applications only). The ISTMT report must include a photograph of the tested TMP for the DLC reviewer to compare with the schematic diagram of the TMP specified by the LED manufacturer/driver manufacturer (for Premium applications only) in supporting application materials.

During the temperature testing of a product, thermocouple wires are permitted to run through a hole in the luminaire, following the guidance described in the ENERGY STAR® Manufacturer’s Guide for Qualifying Solid State Lighting Luminaires.

  • Thermocouples should be installed so as not to alter the thermal characteristics of the luminaire housing.

Please note that the DLC does not endorse any laboratory meeting these requirements. Laboratories expressing the ability to qualify products and laboratory test reports that indicate product performance meets DLC Technical Requirements do not represent official DLC product qualification. All decisions regarding product qualification are made by the DLC. DLC reviewers reserve the right to request documentation to clarify testing conditions or to confirm testing has been conducted by a laboratory that meets these requirements at the time of testing. Please review the FAQs page for additional policy clarifications.