High-Risk Works and Specific Procedures

7.1 Hot Work (Welding and Cutting)

“Hot work” refers to any operation that generates flames, sparks, or sufficient heat to initiate combustion.

• Physical Risks: UV/IR radiation (eye damage), burns, and electric shocks.
• Chemical Risks: Welding fumes (suspended metal particles).

Critical Measures:

• The 15-Meter Rule: Remove all flammable material within this radius or cover it with fire-retardant blankets.
• Fire Watch: A person must monitor the area during the task and for 30–60 minutes after completion.
• Ventilation: Use local exhaust ventilation (LEV) to capture fumes at the source.

7.2 Excavations and Underground Work

The most serious danger in an excavation is not just a cave-in, but interference with hidden utilities.

• KLIC Protocol: Before breaking ground, consult maps for underground pipes and cables.
• Wall Stability: For depths exceeding 1 meter, shoring (bracing) or battering (sloping) is mandatory to prevent burial.
• Material Stockpiling: Excavated soil and machinery must be kept at least 1 meter away from the edge.

7.3 Confined Spaces

A confined space is not designed for continuous human occupancy and has limited entry/exit openings.

• Atmospheric Testing: Before entry, measure O₂ (19.5%–23.5%), flammable gases (LEL), and toxic gases (H₂S, CO).
• Safety Watch (Standby Person): Stationed outside, maintaining constant communication. Never enters for rescue without proper equipment.
• Rescue Plan: Availability of a rescue tripod, harness, and self-contained breathing apparatus (SCBA).

7.4 Working at Heights and Floor Openings

• Collective Protection (Priority): Guardrails (handrail at 1m, intermediate rail, and toe board) and safety nets.
• Individual Protection: Fall arrest harness connected to a certified anchor point.
• Floor Openings: Must be covered with materials that support at least twice the intended weight, secured against accidental movement, and clearly marked.

7.5 Demolition and Hazardous Substances

• Demolition Order: Always from top to bottom and in the reverse order of the building’s construction.
• Asbestos: If asbestos is suspected, work must stop immediately. Only certified companies with decontamination equipment are permitted to handle it.

Comparative Table of Control Measures