Effective May 15, 2017

Standard Information
Standard Number:
UL 998 / CSA C22.2 No. 104
Standard Name:
Standard for Safety for Humidifiers
Standard Edition and Issue Date:
UL 998 5th Edition Dated April 25, 2011
CSA C22.2 No. 104 4th Edition Dated April 25, 2011
Date of Revision:
April 4, 2016
Date of Previous Revisions to Standard:
5th Edition Revised May 19, 2011
Effective Date of New/Revised Requirements

Effective Date (see Schedule below): May 15, 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requests in writing that current requirements be used along with their understanding that their listings will be withdrawn on Effective Date noted above, unless the product is found to comply with new/revised requirements.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: Revision to allow additional VW-1 rated insulating materials, Conductor size of internal wire, Revision to allow power input in amperes, watts, or kilowatts for input test, Addition of grounding symbol New supplement SA - smart enabled humidifiers. Updated references to UL Standards. 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:

  • September 15, 2016 = 8 Month Report Review – Intertek will review all Reports. Update if compliance is verified or issue Findings Letter/Quote for any re-evaluations needed
  • November 15, 2016 = 6 Month Quote Cut-off – Quotes returned for necessary re-evaluations
  • April 14, 2017 = 30 Day Warning – Client advised of all non-compliant Reports to be Suspended
  • May 15, 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
5.2.5InfoRevision to allow additional VW-1 rated insulating materials
25.5 Added clause

Except as specified in Clause 25.6 and 25.7, conductors shall have an ampacity acceptable for the particular application and in accordance with the following: a) For cord-connected equipment, not less than one-third of the required ampacity of the power supply cord; or b) For permanently connected equipment, not less than one-third of the required ampacity of the branch circuit conductors.

Note 1: This requirement does not apply to conductors that are 18 AWG or larger, not more than 1.2 m (4 ft) in length and provided with overcurrent protection in the equipment at the point where the smaller conductor receives its supply.
Note 2: This requirement does not apply to conductors that are connected between two fixed impedances that reduce the risk of a high fault current within the conductors (e.g., a conductor extending between a motor-running capacitor and the start-winding of a permanent split capacitor motor)
Note 3: This requirement does not apply to conductors that are a jumper lead between controls and are not longer than 76 mm (3 in), unless the conductor is located in a control panel.
56.1InfoRevision to allow power input in amperes, watts, or kilowatts for input test
31.2.2 Revised 31.2.2 addition(s) underlined below.
A pressure wire connector intended for connection of such a conductor shall be plainly identified by marking it ″G″, ″GR″, ″GND″, ″Ground″, ″Grounding″, the grounding symbol (from IEC 60417, Symbol 5019) as illustrated in Figure 8A, or the like, or by a marking on a wiring diagram provided on the product.

Addition of grounding symbol (Figure 8A)
 New supplement SA - smart enabled humidifiers
5.3.2InfoUpdated references to UL Standards

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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