Understanding Canadian Pipe Marking Standards (CAN/CGSB-24.3-12) and Hazard Symbols

Proper pipe marking is an essential safety element in most workplaces, helping workers, contractors, and emergency responders quickly identify pipe content and associated hazards. In Canada, the CAN/CGSB-24.3-12 standard, developed by the Canadian General Standards Board (CGSB), outlines specific guidelines for labeling pipes. This standard covers the use of colors, text, flow direction, and, where applicable, WHMIS (Workplace Hazardous Materials Information System) pictograms for hazardous materials, as well as placement rules for various types of pipes.

In this blog, we will cover the key requirements of CAN/CGSB-24.3-12 standard, its color-coding system, placement guidelines, and how it intersects with mandatory WHMIS regulations to ensure comprehensive safety and compliance.

Requirements of CAN/CGSB-24.3-12 Standard

The CAN/CGSB-24.3-12 standard lays out specific requirements for the content, layout, size, color-coding, in some cases, pictograms, and placement of pipe markers. These requirements ensure that labels are both visible and informative in a variety of workplace settings.

Content and Layout

Let’s look at what the pipe label should contain and how this information should be presented and organized.

• Legend: The CAN/CGSB-24.3-12 standard requires pipe labels to clearly identify the contents of the pipe using text, such as Steam, or Electrical (for conduits), on a background colour that denotes the material category. The standard dictates the use of contrasting colours for text and background to ensure high visibility and legibility, meaning the text is typically white on dark backgrounds or black on light backgrounds.
• Standard Size: The Canadian pipe marking standard uses the diameter of the pipe to determine the minimum size of the letters and the overall label. The suggested minimum height of the legend is 13 mm, while the minimum specified length of the colour field is 200 mm. For the identification of small pipes (less than 19 mm in diameter), the use of tags or wall markings is recommended.
• Direction of Flow: An arrow must be included on the label to clearly indicate the direction in which the material is flowing within the pipe. The arrow should be the same colour as the legend text.
• Supplementary Information: Where applicable, additional information must be included in the pipe label. This can include temperature, pressure, or the words "Liquid" or "Gas".
• Standardized Pictograms: For controlled or hazardous materials, appropriate WHMIS pictograms or hazard symbols must be placed on the label. Multiple symbols may be used if a substance presents more than one hazard.

Color Coding Requirement

Like the ANSI/ASME standard, CAN/CGSB-24.3-12 also requires that pipe markers use specific background colors to indicate the general category of the pipe’s contents. These colors are based on the CGSB 1-GP-12 standard and help distinguish between hazardous materials, inherently low-hazard materials, and fire protection systems. For example:

• Black text on a yellow background for hazardous materials
• White text on a green background for inherently low-hazard materials
• White text on red background for fire protection systems

Color coding, combined with the legend and flow direction arrows, ensures clear identification of pipe contents and hazards, helping to improve safety and efficiency.

Placement and Spacing of Labels

Proper placement and spacing of pipe labels is as important for legibility as their size, colour, and content. Labels should be positioned so they are easily visible from the normal angle of approach. For example, overhead pipes should have labels placed below the centerline, while pipes below eye level should have labels above the centerline. Labels should be secured at both ends of the marker with black tape and applied at key locations, including:

• On straight pipe runs at intervals of approximately 6 meters
• Near all valves
• Where pipes pass through walls or floors
• At branches, fittings, or junction boxes
• Adjacent to all changes in direction
• At the beginning and end of each run, as well as at each piece of equipment

Correct label placement ensures that personnel can quickly identify pipe contents and flow direction, and promotes safety and efficient maintenance operations.

Pictograms Approved By CGSB and WHMIS

As mentioned earlier, the CAN/CGSB-24.3-12 requires the use of standardized pictograms for piping systems carrying controlled or hazardous materials. These symbols, approved under CGSB guidelines and required by WHMIS, complement the legend, color coding, and flow direction arrows. Let’s look at the ten pictograms approved under WHMIS:

Exclamation Mark: Acute toxicity, skin or eye irritation
Flame: Flammable materials
Flame Over Circle: Oxidizing materials
Gas Cylinder: Gases under pressure
Corrosion: Corrosive materials
Exploding Bomb: Explosives
Skull and Crossbones: Fatal toxicity
Health Hazard: Long-term health effects (e.g., carcinogens, respiratory sensitizers)
Biohazardous Infectious Materials: Biohazardous agents (unique round black border)
Environment: Aquatic toxicity (generally voluntary in workplace labeling)

Using these pictograms on pipe markers ensures quick hazard recognition, enhancing safety and compliance across facilities.

Clear and compliant pipe marking is essential for workplace safety, efficient operations, and ensuring compliance. Following CAN/CGSB-24.3-12 ensures pipe contents, flow direction, and hazards are instantly recognizable through consistent color coding, legends, and WHMIS pictograms.

Using high-quality pipe markers and labels not only helps meet regulatory requirements but also protects personnel and prevents costly mistakes. Invest in proper labeling materials and supplies to improve safety, simplify maintenance, and ensure your facility stays compliant