Summary of Topics

This Seventh Edition of CAN/ULC 601 dated August 21, 2026 includes the following changes in requirements:

– Consideration for Tank Geometries Other Than Cylindrical or Rectangular: 1.10, 3.21, 4.4.5, 5.1.6, Table 5.2, Table 12.1, subsection 5.9, and Section 18– Rectangular Tank Thickness: 5.5.1.2– Updating the term “Class 3B” to “Class IIIB”: 1.6, 3.18, 3.20, and 16.1(c)– Revision to 1.1 to Improve Clarity– Correcting Cross References throughout the document– Correcting Class II to Class IIIB in 5.7.3– Revising 5.7.2 to align clause with 5.8.2– Adjusting 5.8.3 to reference Section 16 for special markings– Adding wording from 7.2.1 to 6.2.5.1 for improved clarity.– Updating reference to ULC-S663 to UL/ULC 2583– Relocating Specific Gravity Tanks and Static Head Tanks within ULC 601: Section 8 and Section 9– Revisions to 5.6.1.3 Venting– Alternative Joint Requirements: 4.3.1 (Note) and 4.3.4– Relocating 5.4.1, Tailing lugs and anchors, to 4.8, Lifting – Revising 10.6.1– Adding Alternative to Section 12, Production Leak Test: 12.4– Revise Marking Text for Tanks Where Factory-Installed E-Vent is not Present: 15.4(c)(2)– Revise 6.2.3.1 Regarding Secondary Containment Head Thickness: 6.2.3.1– Revisions to 4.6 (Venting) and addition of Annex F– Revisions to 7.2 Interstitial Space Inspection and Emergency Vents

1 Scope

1.1 This Standard sets forth minimum requirements for steel, non-pressure tanks that are used for the aboveground storage of flammable and combustible liquids compatible with the material of construction and with a specific gravity not greater than 1.0.

1.2 This Standard also sets forth minimum requirements for steel, non-pressure tanks that are used for the aboveground storage of flammable and combustible liquids compatible with the material of construction and with a specific gravity greater than 1.0, which are covered in Section 8, and static head tanks, which are covered in Section 9.

1.3 This Standard also sets forth traditional safety requirements for aboveground steel tanks that primarily evaluate structural integrity and mitigate environmental hazards from loss of liquid containment under expected normal conditions. Optional construction and/or performance requirements, and associated ratings intended to address more severe conditions associated with the effects of Climate Change are included in Annex D.

NOTE: These tanks may also be used for the storage of used oil. For tanks intended solely for the collection of used oil, refer to ULC 652, Standard for Tank Assemblies for the Collection, Storage and Removal of Used Oil.

1.4 This Standard covers tanks, which are fabricated, inspected and tested for leakage before shipment from the factory.

1.5 This Standard covers the construction of tanks for use in stationary installations. Tanks fabricated in accordance with this Standard are not intended for the transportation of flammable and combustible liquids nor are they intended to be transported while containing such liquids.

NOTE: Relocation of tanks other than utility tanks is subject to the requirements of the authority having jurisdiction.

1.4 The installation of such tanks shall be in accordance with, but not limited to, the following documents:

1. a) National Fire Code of Canada, Part 4;

2. b) CSA B139, Installation code for oil-burning equipment;

3. c) CCME Environmental Code of Practice for Aboveground and Underground Storage Tank Systems Containing Petroleum and Allied Petroleum Products; and

4. d) Regulations of the appropriate authority having jurisdiction.