DarkSky Approved Luminaires guidelines

Version 3.0, updated March 2025

Introduction

The DarkSky Approved Luminaires program was established by DarkSky International to promote high-quality lighting for outdoor environments that minimizes light pollution, including sky glow, light trespass, obtrusive light, and harmful impacts to people, wildlife, and plants.  

The program gives recognition to those lighting products that give the same high priority to environmental protection and nuisance avoidance as they do to lighting for their intended function. For a luminaire to be DarkSky Approved, it must demonstrate that it meets the criteria in this document, which are based on the objectives of the Five Principles for Responsible Outdoor Lighting. Those Principles are:

1. All light should have a clear purpose.
2. Light should be directed only to where it is needed.
3. Light should be no brighter than necessary.
4. Light should be used only when it is useful.
5. Warmer-color lights should be used where possible.

This document explains the requirements for luminaires to become DarkSky Approved, including both technical performance specifications and administrative requirements.

For questions on the program, please contact the Lighting Program Manager. 

Download the guidelines

Luminaires Program Guidelines v3.0_2025-02.20.pdf (PDF)

TABLE OF CONTENTS (Jump to)

1.0 GENERAL

1.1 Overview

1.2 Exclusions

1.3 Definitions

2.0 Lighting criteria

2.1 DarkSky Residential Luminaire criteria

2.2 DarkSky Commercial Luminaire criteria

2.3 DarkSky Pedestrian Comfort Luminaire criteria

2.4 DarkSky Wildlife Tuned Luminaire criteria

3.0 Submission process

3.1 Application and deliverables

3.2 Fees

4.0 Approval terms and limitations

4.1 Terms

4.2 Limitations

APPENDIX A – BACKGROUND

1.0 GENERAL

1.1 Overview

A. Scope: This program provides DarkSky International approval for luminaires designed to mitigate light pollution. 

B. DarkSky Approved Luminaires: DarkSky International issues approval for outdoor luminaires that have a valid electrical safety certification and meet our guidelines to reduce light pollution (see Section 2.0 Lighting criteria). Manufacturers must demonstrate conformance by providing all required documentation. (See Section 3.0 Submission process.) DarkSky Approved luminaires are grouped into these categories:

1. DarkSky Residential Luminaires: Outdoor luminaires that are primarily used on properties of single-family dwellings or residences with up to four connected units (four-plex) or town homes.  
2. DarkSky Commercial Luminaires: Outdoor luminaires that are used on properties of commercial or industrial businesses and places with high traffic, such as schools, hotels, and shopping malls, as well as public spaces or rights-of-way, including streets, roadways, and government facilities. 
3. DarkSky Pedestrian Comfort Luminaires: These are lower-lumen output Commercial Luminaires that are generally used for pedestrian walkways and local streets only, with additional restrictions on light output, and high-angle light emissions for luminaires mounted more than 1.2 meters above grade, to reduce obtrusive light, minimize light trespass, and promote improved visual comfort; under normal circumstances these luminaires are spaced no further than six mounting heights apart.  When luminaires from this category are applied, ensure that proper spacing and mounting heights are used in order to meet required illumination and uniformity recommendations
4. DarkSky Wildlife Tuned Luminaires: Luminaires with shielding and color spectra tuned to protect specific species habitats (e.g., Sea Turtle Sensitive Luminaires).

C. Multiple listings: The categories listed above are used within the DarkSky Approved searchable database to assist customers looking for specific luminaire types or for luminaires with specific qualities. Manufacturers may list their products in multiple categories. (See Section 3.2 Fees.) 

1.2 Exclusions

A. Variable CCT: The maximum CCT for color tunable or field-selectable CCT products is 3000 K; products with options for CCTs higher than 3000 K are not eligible for the DarkSky Approved Luminaires program.

B. Adjustable mounting: Luminaires with adjustment mechanisms that allow an upward tilt angle are not permitted.

C. Safety certification: Products must have independent third-party electrical safety certification by a nationally recognized testing laboratory (e.g., UL, ETL, CSA, CE, TUV, ENEC). Products without electrical safety certification are not eligible for the DarkSky Approved Luminaires program, with an exception for fully off-grid solar lighting products that operate at 48 V DC or lower.

D. Dimming: Products over 500 lumens without an option for dimming to 10% or less of full output rating are not eligible for the DarkSky Approved Luminaires program. Dimming must be included in the product data sheet ordering matrix.

E. Specialty application luminaires: Products designed for a specific application must be qualified through a DarkSky Approved application-based program if one exists. For example, sports lighting luminaires are not eligible for the DarkSky Approved Luminaires program, since there is a DarkSky Approved Outdoor Sports Lighting program.

1.3 Definitions

A. CCT (correlated color temperature): The measured color appearance of light emitted by a light source described using a nominal value in kelvins (K). Lower CCTs (1800 K to 2200 K) appear very warm or amber. Medium CCTs (2700 K to 3000 K) appear “warm white,” similar to standard incandescent bulbs. High CCTs (4000 K and higher) appear “cool white” or “blue.”

B. Luminaire Classification System: Described in ANSI/IES TM-15-20, this is a luminaire classification system (LCS) for outdoor luminaires that provides information to lighting professionals regarding the lumen distribution within emission angles of specific interest. Light emissions within specific zones of the LCS may have limitations in the DarkSky Approved Luminaires program. 

C. Nadir: The vertical direction that extends straight down from a luminaire’s light source. Photometrically, this is a vertical angle of 0 degrees.

D. Shielding option: A solid opaque material shaped to reduce or eliminate the direct view of the light source when viewed from a particular side or from a long distance. Examples include house-side shields, beach-side shields, cul-de-sac shields, side shields, and louvers. 

E. Spectral content: A representation of the radiant power emitted by a light source at each wavelength or band of wavelengths in the visible region of the electromagnetic spectrum. 

F. Type V distribution: A classification of luminaire light distribution that has a circular symmetry of candlepower distribution that is essentially the same at all lateral angles around the luminaire. The pattern of light on the ground will be approximately circular.

G. Type VS distribution: A classification of luminaire light distribution where the zonal lumens for each of the eight horizontal octants (0-45, 45-90, 90-135, 135-180, 180-225, 225-270, 270-315, and 315-360 degrees) are within ±10 percent of the average zonal lumens of all octants. The distribution is similar to the Type V distribution but has a square shape.

H. Uplight:   Any light output between 90 and 180 degrees above nadir, inclusive (i.e., LCS zones UL and UH combined). Note: All uplight allowances given within these Guidelines are based on uplight as a reflected byproduct of the structure of the luminaire, and not the light source.

2.0 Lighting criteria

2.1 DarkSky Residential Luminaire criteria

A. Output: Luminaire total light output shall not exceed 1,000 lumens.

B. Uplight: No more than 50 lumens are allowed between 90 and 180 degrees above nadir (i.e., LCS zones UL and UH combined). The light source shall not be visible from the horizontal plane that passes through the lowest light-emitting part of the luminaire.

C. CCT: The light source CCT shall not exceed 3000 K.

D. Dimming: The luminaire shall be dimmable to 10% or less of its full light output rating.

2.2 DarkSky Commercial Luminaire criteria

A. Uplight: The following are maximum percentages of total luminaire lumens, or maximum lumen amounts, allowed between 90 and 180 degrees above nadir, inclusive (i.e., LCS zones UL and UH combined):

1. Luminaires emitting 1,000 lumens or less: A maximum of 5 lumens total is allowed.
2. Luminaires emitting more than 1,000 lumens: No more than 0.5% of the total luminaire lumen output is allowed, up to a maximum of 50 lumens.

B. High angle light: The following are maximum percentages of total luminaire lumens allowed between 80 degrees and 90 degrees from nadir (i.e., LCS zones FVH and BVH combined):

1. Luminaires with a Type V or Type VS light distribution (see Sections 1.3.F and 1.3.G, respectively): No more than 5% of the total luminaire lumen output is allowed. 
2. Luminaires with all other distribution types: No more than 3% of the luminaire’s total lumen output is allowed.

C. Shielding option: For pole mounted street, area, roadway, and parking lot luminaires a pre- or post-installation shielding option must be available and included in the product data sheet (See Section 1.3.D).

D. CCT: The light source CCT shall not exceed 3000 K.

E. Dimming: The luminaire shall be dimmable to 10% or less of its full light output rating.

2.3 DarkSky Pedestrian Comfort Luminaire criteria

A. Output: The luminaire total light output shall not exceed 10,000 lumens.

B. Uplight: The following are maximum percentages of total luminaire lumens, or maximum lumen amounts, allowed between 90 and 180 degrees above nadir, inclusive (i.e., LCS zones UL and UH combined):

1. Luminaires emitting 1,000 lumens or less: A maximum of 5 lumens total is allowed.
2. Luminaires emitting more than 1,000 lumens: No more than 0.5% of the total luminaire lumen output is allowed, up to a maximum of 50 lumens.

C. High angle light: For luminaires whose lowest light emitting surface is more than 1.2 meters (4 feet) above the ground, the following are maximum percentages or values allowed in the specified LCS zones or angles above nadir:

1. No more than 2% of the luminaire’s total output shall be emitted between 80 and 90 degrees above nadir (i.e., LCS zones FVH and BVH combined).
2. No more than 35% of the luminaire’s total output shall be emitted between 60 and 80 degrees above nadir (i.e., LCS zones FH and BH combined). 
3. The vertical angle of maximum luminous intensity (candelas) shall be no higher than 68 degrees above nadir.  

D. CCT: The light source CCT shall not exceed 3000 K.

E. Dimming: The luminaire shall be dimmable to 10% or less of its full light output rating.

2.4 DarkSky Wildlife Tuned Luminaire criteria

A. Criteria for Sea Turtle Sensitive Luminaires

1. Output: The luminaire total light output shall not exceed 4,000 lumens.
2. Uplight: No light output shall be emitted between 90 and 180 degrees above nadir, inclusive (i.e., LCS zones UL and UH combined). 
3. High angle light, for luminaires of all heights:
   • No more than 2% of the luminaire’s total output shall be emitted between 80 and 90 degrees above nadir (LCS zones FVH and BVH combined).
   • No more than 35% of the luminaire’s total output shall be emitted between 60 and 80 degrees above nadir (i.e., LCS zones FH and BH combined).  
   • The vertical angle of maximum luminous intensity (candelas) shall be no higher than 68 degrees above nadir.
   • Luminaires must have enhanced shielding that is included in the product data sheet. This option is required for shielding the light source on the beach side of the luminaire.
4. Spectral content: The luminaire’s emitted spectral power shall be at wavelengths of 560 nm or longer.  The graph on the left displays an acceptable wavelength reading for a long-wavelength light source (i.e. amber lamp), with wavelength readings above 560 nm or higher.  The graph on the right displayed an unacceptable wavelength reading, with wavelength readings below the 560 nm cutoff. 

5. Dimming: The luminaire shall be dimmable to 10% or less of its full light output rating.

3.0 Submission process

3.1 Application and deliverables

A. Application

1. Applicants must apply for DarkSky approval by uploading all information requested in the online submission form, as well as the supplemental documents listed in Section 3.1.B Submission requirements. 

B. Submission requirements

1. Image file (e.g., JPG, GIF, PNG) of the product for use on the DarkSky website
2. Manufacturer product data sheet:
   1. Product families for which all models are compliant:  A data sheet is required for each family application being submitted.  The DarkSky Approved logo may be used on all pages of the product data sheet package.
   2. For product families available with non-compliant models and/or options:  The manufacturer must supply a dedicated ordering matrix with only DarkSky-compliant options on the product data sheet. The ordering matrix shall be limited to include only product codes that meet the DarkSky Approved Luminaire program requirements. The ordering matrix shall be labeled as DarkSky Approved and is required in order for the application to be approved. The DarkSky Approved logo may be used only on the pages of the product data sheet package that limit the product offering to DarkSky Approved product codes, except that it may also be used on the first page of the product data sheet with a reference to the page that includes the DarkSky Approved ordering matrix. It is preferred to have a dedicated spec sheet as described in section 3.1.B.2.a. 
   3. For pole mounted street, area, roadway, and parking lot luminaires: A pre- or post-installation shielding option must be available and included in the product data sheet (See Section 1.3.D). 

3. A photometric file (IES or LDT format) and original test lab report (pdf format) is required for each distribution type offered at the highest power level offered. Simulated photometry will not be accepted. Photometric files and reports must include vertical measurements from 0 to 180 degrees in increments of no more than 5 degrees for both front and back halves of the distribution. Photometric files and reports must include horizontal measurements from 0 to 360 degrees in increments of no more than 15 degrees. 
   • Only photometric reports by an ISO 17025 accredited test laboratory with a scope including goniophotometer testing to IES LM-79-2019, EN 13032-1 or EN 13032-4 will be accepted.  The accreditation body used must be displayed on the front page of all photometric test reports submitted.  A list of approved accreditation bodies can be referenced here.

4. Independent third-party electrical safety certificate from a nationally recognized testing laboratory. (Examples include UL, ETL, CSA, CE, TUV, ENEC.)
5. For Wildlife Tuned Luminaire submissions only: Spectral content data (pictorial, graphic, or tabular), to validate spectral characteristics (refer to Section 2.4 Wildlife tuned luminaires).
6. All documents submitted must include the product code/model number, or product family name as part of the filename.  

3.2 Fees

Fees are found here.

4.0 Approval terms and limitations

4.1 Terms

Process and schedule: 

1. Once the submission requirements and deposit fee (see Sections 3.1.B and 3.2, respectively) have been uploaded via the online submission form, the submitter will be contacted and provided the application fee total and any feedback related to the submission. 
2. Missing, unclear, or incorrect information may extend the review process beyond the standard turnaround time. 
3. Only submissions made through the online submission form will be considered for review and approval. 
4. Once all of the correct information and documents have been received, the review process has a typical turnaround time of five to ten business days. 
5. DarkSky Approval Certificates are typically sent via email three to five business days after receipt of final payment. At this time, the approved products will also be displayed on the DarkSky Approved Luminaires webpage.

4.2 Limitations

Compliance: DarkSky Approval is given only for products for which full compliance with the lighting criteria described in this document (see Section 2 Lighting Criteria) has been demonstrated and all supporting documentation and payment has been received. 

APPENDIX A – BACKGROUND

DarkSky International is the authoritative voice on light pollution. DarkSky International educates lighting designers, manufacturers, technical committees, and the public about controlling light pollution. We recognize that the best way to accomplish our goal of protecting and restoring our natural nighttime environment is through the promotion of quality outdoor lighting. To achieve this, we developed the DarkSky Approved Luminaires program (formerly, Fixture Seal of Approval program) to provide objective, third-party review of exterior luminaire lighting performance to ensure it meets our criteria for reducing obtrusive light, light trespass, and sky glow.

Contact

To learn more, contact the DarkSky Lighting Program Manager.