The IAPMO Standards Council on Nov. 4 issued a tentative interim amendment (TIA) to the 2024 edition of the Uniform Mechanical Code (UMC).

UMC TIA 003-24 revises UMC Chapter 11, Table 1102.3 (Refrigerant Groups, Properties, and Allowable Quantities), to update the permissible refrigerant quantities pertaining to refrigerant concentration limits (RCLs) and lower flammability limits (LFLs).

The TIA was balloted through the Mechanical Technical Committee in accordance with the Regulations Governing Committee Projects to determine if there was the necessary three-fourths majority support, based on technical merit and emergency nature, to establish the recommendation for issuance.

In determining whether to issue a TIA, the Standards Council looks to the Technical Committee letter ballot for a recommendation of support. Upon a full review and consideration of all the information available to it, the Council concluded that a clear and substantial basis exists to issue UMC TIA 003-24.

To examine this TIA in its entirety, please view: https://www.iapmo.org/media/n0edywdo/2024-umc-tia-003-issued.pdf

TIAs are proposals based on the determination of an emergency nature requiring prompt action to amend code that contains an error or omission that was overlooked during the regular code development process, contains a conflict within the document or with another IAPMO document, or to correct a hazard, promote an advancement in safeguarding the public or provide an opportunity to correct an adverse impact on a product or method of installation.