907.1 General
Factory-built cremation furnaces and commercial direct-fed incinerators must be listed and labeled to UL 2790. Factory-built incinerators for domestic applications must be listed and labeled to UL 791. Every incinerator and cremation furnace is installed in accordance with the manufacturer’s instructions.
Two approval paths
Commercial direct-fed incinerator or factory-built cremation furnace → UL 2790.
Factory-built incinerator for a domestic application → UL 791.
A schedule tag that only says “incinerator” leaves the reviewer to guess which standard applies. Classify the equipment first, then verify the listing.
What the listing pulls in
The listing starts the review; it does not finish it. The manufacturer’s instructions set clearances, the chimney or vent connection, combustion air and the fuel supply, and those carry the design into IMC Chapters 3, 7 and 8 and the fuel-gas code. Emissions are outside the mechanical code: ask early whether an air-quality permit applies to the project.
Where to show it
As applicable: the equipment schedule with type, manufacturer, model and listing standard; equipment plans; sections and installation details; specifications; manufacturer product data; and the listing documentation.
Do
Identify the exact equipment type.
Verify the correct UL listing standard.
Name the manufacturer and model.
Coordinate the installation with the manufacturer’s instructions.
Make the listing path visible on the permit documents.
Do not
Treat every incinerator as governed by the same listing.
Specify the equipment generically without the approval path.
Assume the field installation can differ from the manufacturer’s instructions.
Leave the reviewer to decide whether UL 2790 or UL 791 applies.
Field tip
When versions of similar equipment use different listing standards, classify the equipment before reviewing the installation: equipment type → applicable listing → manufacturer instructions → coordinated permit details. That keeps the wrong approval standard out of design and submittal review. Next: #174 — IMC 908.1–908.4 Cooling Towers (1/3).
Code basis
2024 IMC 907.1 model-code education from the owner-provided Daily Code Talk; the two listing standards match the published 2024 IMC text. Confirm the adopted edition, the listing and the manufacturer’s instructions. Not an equipment selection.