Effective April 28, 2017

Standard Information
Standard Number:
UL 844
Standard Name:
Luminaires for Use in Hazardous (Classified) Locations
Standard Edition and Issue Date:
13th Edition Dated June 29, 2012
Date of Revision:
March 11, 2016
Date of Previous Revisions to Standard:
13th Edition Revised November 13, 2015
Effective Date of New/Revised Requirements

Effective Date (see Schedule below): April 28, 2017

Impact, Overview, Fees and Action Required

Impact Statement: A review of all Listing Reports is necessary to determine which products comply with new/revised requirements and which products will require re-evaluation. NOTE: Effective immediately, this revised standard will be exclusively used for evaluation of new products unless the Applicant requests in writing that current requirements be used along with their understanding that their listings will be withdrawn on Effective Date noted above, unless the product is found to comply with new/revised requirements.

Overview of Changes: UL 844 was revised to include minimum glass thickness requirements for Class I, Division 1 luminaires. Specific details of new/revised requirements are found in table below.

If the applicable requirements noted in the table are not described in your report(s), these requirements will need to be confirmed as met and added to your report(s) such as markings, instructions, test results, etc. (as required).

Schedule: So that shipping of products with Listing Marks will not be interrupted, an approximate schedule has been established to ensure Listing Reports are found compliant by Effective Date:

  • August 30, 2017 = 8 Month Report Review – Intertek will review all Reports. Update if compliance is verified or issue Findings Letter/Quote for any re-evaluations needed
  • October 31, 2017 = 6 Month Quote Cut-off – Quotes returned for necessary re-evaluations
  • April 28, 2017 = Effective Date – ATM Suspended for all non-compliant Reports

Fees: An initial review of Listing Report (s) will be covered by a direct billing project and will be invoiced at not more than $1000 per report.

Client Action Required:

Information – To assist our Engineer with review of your Listing Reports, please submit technical information in response to the new/revised paragraphs noted in the attached or explain why these new/revised requirements do not apply to your product (s).

Current Listings Not Active? – Please immediately identify any current Listing Reports or products that are no longer active and should be removed from our records. We will do this at no charge as long as Intertek is notified in writing prior to the review of your reports.

Description of New/Revised Technical Requirements
10InfoEnclosure Thickness
10.1InfoEnclosures for Class I locations New subsection added;

Glass The thickness of a flat panel of glass, smooth or otherwise, shall not be less than specified in Table 10.3. The thickness of a glass lens, glass that is curved or bent, and glass having other shapes shall also not be less than specified in Table 10.3. The minimum thickness of fluted, ribbed, or patterned glass is to be measured from a valley to the other side, or between valleys on opposite sides.

CUSTOMERS PLEASE NOTE: This Table and column "Verdict" can be used in determining how your current or future production is or will be in compliance with new/revised requirements.

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