Cutting High-Density Polyethylene and Reinforced Concrete Pipe with handheld cut-off saws

Overview

There have been recent reports of several serious incidents involving cutting High-Density Polyethylene (HDPE) and Reinforced Concrete Pipe (RCP) pipe with handheld saws in Manitoba.

Why cutting HDPE with abrasive blades is a concern:

• Material properties: HDPE is a heat-sensitive thermoplastic with a melting point of 120–180°C.
• Blade temperatures: Segmented diamond blades often reach 250–700°C, creating a high risk of overheating. Excessive heat can melt HDPE, causing material to fuse to the blade. This can lead to:
  • Blade binding and seizure.
  • Increased risk of kickback.
  • Further melting if additional force is applied.

Additional risks when cutting RCP

• Asbestos hazard: Some reinforced concrete pipes contain asbestos, a known carcinogen linked to:
  • Asbestosis
  • Lung cancer
  • Mesothelioma
• Exposure risk: Cutting RCP can release asbestos fibres, which can be inhaled by workers.
• Employer responsibilities:
  • Maintain an asbestos inventory.
  • Ensure testing by a competent person.
  • Implement a control plan with safe work procedures for asbestos remediation.

Prevention measures

Employers must:

• Comply with regulations:
  • Use tools and equipment only for their intended purpose (Part 16.4(1) & 16.4(3), Workplace Safety and Health Regulation).
  • Ensure workers are trained and competent in safe saw operation (Part 16.2(1)).
• Prohibit abrasive blades for HDPE:
  • Use fine-tooth carbide blades with lubricant for heat control.
• Safe cutting practices:
  • Make multiple cuts for large-diameter HDPE/RCP.
  • Support pipes to prevent movement.
  • Use wedges to maintain gaps.
  • Follow manufacturer specifications.

If you have questions about this topic, contact the SAFE Work Manitoba division.