Effective July 29, 2016

Standard Information
Standard Number:
UL 2034
Standard Name:
Single and Multiple Station Carbon Monoxide Alarms
Standard Edition and Issue Date:
3rd Edition Dated February 28, 2008
Date of Revision:
March 26, 2015
Date of Previous Revisions to Standard:
3rd Edition Dated February 20, 2009
Effective Date of New/Revised Requirements

Effective Date (see Schedule below): July 29, 2016

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requests in writing that current requirements be used along with their understanding that their listings will be withdrawn on Effective Date noted above, unless the product is found to comply with new/revised requirements.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: The changes with respect to the previous revision include additional testing requirements. Specific details of new/revised requirements are found in table below.

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:

  • November 27, 2015 = 8 Month Report Review – Intertek will review all Reports. Update if compliance is verified or issue Findings Letter/Quote for any re-evaluations needed
  • January 29, 2016 = 6 Month Quote Cut-off – Quotes returned for necessary re-evaluations
  • June 27, 2016 = 30 Day Warning – Client advised of all non-compliant Reports to be Suspended
  • July 29, 2016 = 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 – Please immediately identify any current Listing Reports or products that are no longer active and should be removed from our records.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
36InfoNormal Operation Test

Additions to existing requirements are underlined below.

Any indicator of CO concentration shall be accurate to within plus or minus 30% of the indicated amount and display the gas concentration for all Sensitivity tests specified in Table 39.1 and pre/post Sensitivity tests within this standard. No indication shall be given for CO concentrations less than 30 ppm. The indicator shall comply with the in-service reliability requirements of 78.1.2. Testing shall be performed at 70, 150, and 400 ppm and the test data shall be part of the in-service reliability measurement program. For the purposes of these requirements, an indicator of CO concentration shall be either an integral component of a CO alarm or a remote indication provided at an external device, such as a remote receiver or a mobile device, i.e. smart phone.

Rational: If provided, visual displays are required to perform over the life of the product and operate within the parameters defined within this standard. Although it is not the primary alarm feature, if the alarm signal is initiated and the display is not active, the user could interpret this misinformation as a malfunctioning CO alarm.
49InfoTransient Tests

Additions to existing requirements are underlined and deletions are shown lined out below.

Different alarms are to be used for each of the four tests in 49.1.1. The alarms shall not false alarm for more than 1 second. Alarms using a primary battery as a power supply are to be subjected to the extraneous transients test only. If an alarm is intended for multiple-station connection, the transient tests are to be conducted with the maximum number of alarms intended to be connected. When a CO alarm is intended for multiple-station connection, the transient tests are to be first conducted with an individual CO alarm, and secondly with two interconnected CO alarms. The interconnecting wiring shall not exceed 12 in (300 mm).

New sections added;

Surge Immunity Test (Combination Wave)
Surge Current Test

Rational: To maintain consistency among the UL smoke and detector standards, UL is proposing to include surge immunity and surge current test requirements for UL 2034. These tests are identical to those incorporated in UL 217.
83InfoMarking (General)
83.1 (d) 

Additions to existing requirements are underlined below.

An alarm shall be permanently marked on a Class IIIC marking material with the following information unless specifically indicated that it appears on the installation wiring diagram. The marking shall be in a contrasting color, finish, or equivalent. Unless the letter height is specified, all markings shall be at least 3/64 inch (1.2 mm) high.       

d) Correct mounting position if a unit is intended to be mounted in a definite position. Carbon monoxide alarms that comply with shall include marking information that clearly indicates that the product is only intended for installation on the ceiling, or on the wall no more than 12 inches from the ceiling. As an alternative, the correct mounting position shall appear in the installation instructions.

Items (a)-(c) and (e)-(u) remain as is 
84InfoInstructions (General)
84.1 (t) 

Additions to existing requirements are underlined below.

Each single and multiple station carbon monoxide alarm shall be provided with installation instructions which shall include the following information:

t) Products that comply with and are not subjected to the Impact Test, 62.5, shall include information clearly indicating that the user shall actuate the test and/or alarm reset/silence feature remotely (via an electronic signal or aerosol test gas), or by use of a person’s finger or thumb, and that the use of any other instrument(s) is strictly prohibited.

Items (a)-(s) remain as is

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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