Welding & Hot Work Activity Hazard Analysis
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Welding and hot work operations on USACE and DoD construction projects carry some of the highest risk profiles of any Definable Feature of Work. The combination of open flame, molten metal, toxic fumes, and electrical energy creates overlapping hazard zones that demand rigorous pre-task planning. EM 385-1-1 Section 10.B establishes specific requirements for welding, cutting, and brazing that go beyond OSHA general industry and construction standards.
This Activity Hazard Analysis addresses the full scope of welding and hot work as a DFOW under USACE contract requirements. It includes the Risk Assessment Code (RAC) matrix evaluation, identifies competent person designations required by EM 385-1-1, and breaks each operational step into hazards with corresponding controls. The initial RAC of High (2) reflects the critical severity and likely probability of injury without controls. With full implementation of engineering controls, administrative procedures, and PPE, the residual RAC drops to Low (5).
Contractors must submit this AHA to the Contracting Officer Representative (COR) or Safety Office for acceptance prior to commencing welding or hot work operations. All workers involved in the DFOW must review and sign the AHA before work begins each shift. Update the AHA whenever conditions change, new hazards are identified, or after any incident or near-miss.
Disclaimer
This content is provided for general informational and educational purposes only. It is not a substitute for a site-specific Job Safety Analysis conducted by a qualified safety professional familiar with your workplace conditions, equipment, and personnel. OSHA citations, BLS statistics, and hazard controls referenced here may not reflect the most current standards or apply to your specific situation. Always consult current OSHA regulations, manufacturer guidelines, and a competent person before beginning work. Health & Safety Systems LLC assumes no liability for actions taken based on this content.
Definable Feature of Work (DFOW)
Welding, Cutting & Brazing Operations
All arc welding (SMAW, GMAW, GTAW, FCAW), oxy-fuel cutting and brazing, plasma cutting, and associated fire watch activities performed on structural steel, piping, mechanical equipment, and miscellaneous metals. Includes setup, execution, post-weld inspection, and fire watch duration.
Typical Duration: 1-4 weeks depending on scope; individual hot work sessions typically 2-8 hours per shift
EM 385-1-1 References
Section 10.B: Welding and Cutting
Primary section governing all welding, cutting, and brazing operations on USACE projects. Requires hot work permits, fire watch, proper ventilation, equipment inspection, and competent person oversight.
Section 10.B.01: General Welding Requirements
Welding equipment shall be installed, operated, and maintained per manufacturer instructions and NFPA 51B. Only qualified welders shall perform welding operations.
Section 10.B.02: Hot Work Permits
A hot work permit is required for all welding, cutting, and brazing operations performed outside designated permanent welding areas. Permits must be issued by an authorized individual and posted at the work site.
Section 10.B.03: Fire Prevention and Protection
Combustible materials must be relocated at least 35 feet from hot work or protected with fire-resistant covers. A fire watch with appropriate extinguishing equipment must be maintained during and after operations.
Section 06.A: Personal Protective Equipment
PPE selection based on hazard assessment. Welding operations require eye/face protection, flame-resistant clothing, respiratory protection when ventilation is inadequate, and hearing protection when noise exceeds 85 dBA.
Section 09.A: Fire Prevention and Protection Program
Contractor must establish a fire prevention program that includes hot work controls, fire extinguisher placement, and fire watch training requirements.
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Start Free TrialRisk Assessment Code (RAC)
The RAC matrix combines hazard severity and probability to assign a risk level before and after controls are applied. This AHA demonstrates risk reduction from initial to residual conditions.
Initial Risk (Before Controls)
High (2)
Severity: Critical | Probability: Likely
Residual Risk (After Controls)
Low (5)
Severity: Marginal | Probability: Seldom
Step-by-Step AHA Breakdown
Step 1: Review hot work permit and AHA with crew
Hazards
- Workers unaware of site-specific fire hazards or atmospheric conditions
- Failure to identify hidden combustibles in walls, floors, or adjacent spaces
- Inadequate communication with adjacent trades working in the exposure zone
Controls
- Obtain signed hot work permit from authorized permit issuer before any ignition source is introduced
- Conduct AHA review with all crew members and obtain signatures; verify each worker understands their role
- Walk down the work area to identify combustibles, flammable storage, and adjacent operations
- Notify all adjacent trades and post hot work warning signs at access points
Step 2: Inspect welding equipment and compressed gas cylinders
Hazards
- Electrical shock from damaged cable insulation or loose connections
- Uncontrolled gas release from damaged regulators or leaking fittings
- Cylinder tip-over causing valve shear and uncontrolled propulsion
- Flash-back or reverse flow in oxy-fuel systems
Controls
- Inspect all cables, electrode holders, ground clamps, and connections; remove damaged equipment from service
- Verify cylinders are secured upright in a cart or chained to a fixed structure
- Check regulators, hoses, and fittings for leaks using approved leak detection solution
- Confirm flash-back arrestors are installed on both oxygen and fuel gas lines
- Verify welding machine is properly grounded and GFCI protection is functional on auxiliary power
Step 3: Establish fire prevention controls and ventilation
Hazards
- Fire ignition from spatter contacting combustible materials
- Explosion from welding in or near flammable atmospheres
- Accumulation of welding fumes in enclosed or poorly ventilated areas
Controls
- Relocate combustibles 35 feet from hot work or cover with fire-resistant blankets
- Seal floor openings, wall penetrations, and gaps where spatter could travel to concealed spaces
- Position local exhaust ventilation within 12-18 inches of the arc point
- Monitor atmosphere with calibrated 4-gas meter in enclosed or semi-enclosed areas before and during welding
- Stage minimum one 20-lb ABC fire extinguisher within 25 feet of hot work location
Step 4: Don required personal protective equipment
Hazards
- Arc eye (photokeratitis) from UV radiation exposure
- Skin burns from spatter, slag, and radiant heat
- Respiratory illness from inhalation of welding fumes containing hexavalent chromium, manganese, or zinc oxide
- Hearing damage from sustained noise exposure above 85 dBA
Controls
- Wear auto-darkening welding helmet with appropriate shade lens (10-13 for SMAW, 8-12 for GMAW/GTAW)
- Wear safety glasses with side shields under the welding helmet at all times
- Don flame-resistant jacket or coveralls covering all exposed skin; leather gauntlet gloves
- Select respiratory protection based on base metal and filler composition per exposure assessment
- Wear hearing protection when noise monitoring indicates levels above 85 dBA TWA
- Wear steel-toe leather boots; no synthetic materials that can melt
Step 5: Position and secure work piece
Hazards
- Musculoskeletal injury from lifting or positioning heavy steel members
- Crush injuries from unsecured work pieces shifting during handling
- Pinch points when clamping, fixturing, or tacking components
Controls
- Use mechanical lifting aids (crane, forklift, chain hoist) for materials exceeding 50 pounds
- Secure work piece with clamps, fixtures, or tack welds before full welding begins
- Verify stability of the assembly; do not weld on an unsupported or cantilevered piece
- Keep hands clear of pinch points when operating clamps; wear leather gloves during handling
Step 6: Perform welding or cutting operations
Hazards
- Electric shock from contact with energized electrode or work circuit
- UV and infrared radiation exposure to welder and bystanders
- Toxic fume generation (manganese, hexavalent chromium, zinc oxide, cadmium)
- Burns from molten metal, slag, and spatter
- Fire from spatter reaching combustibles beyond the controlled zone
Controls
- Never touch electrode or metal parts of holder with bare skin or wet gloves
- Erect welding screens or curtains on all open sides to protect bystanders from arc flash
- Maintain local exhaust ventilation throughout welding operations; reposition as work progresses
- Maintain dry, insulated footing; use rubber mats when working on steel decking or wet surfaces
- Fire watch continuously monitors for spatter migration and smoldering materials
- Follow approved Welding Procedure Specification (WPS) for all parameters
Step 7: Conduct fire watch during and after operations
Hazards
- Delayed fire ignition from embedded spatter or residual heat in concealed spaces
- Smoldering combustibles below or behind the work area undetected
Controls
- Designated fire watch remains on station during all hot work and for minimum 60 minutes after completion
- Fire watch maintains charged extinguisher and communication device at all times
- Fire watch inspects all adjacent areas, above and below the work zone, for smoke or hot spots
- Document fire watch start and end times on the hot work permit
- Fire watch authority to stop work immediately if fire conditions are detected
Step 8: Perform post-weld inspection and cleanup
Hazards
- Contact burns from handling hot work pieces or slag
- Eye injury from chipping slag without face protection
- Inhalation of grinding dust during weld cleanup
- Trip hazards from cables, hoses, and equipment left in walkways
Controls
- Mark hot metal with "HOT" tags or soapstone markings; use pliers or tongs for handling
- Wear face shield and safety glasses when chipping slag or grinding welds
- Maintain ventilation during all grinding and cleanup operations
- De-energize welding machine and disconnect from power when work is complete
- Coil and store cables; secure cylinders with caps and chain; return equipment to designated storage
- Dispose of electrode stubs and grinding debris in metal waste containers
- Close out hot work permit after fire watch period is complete
Competent & Qualified Persons
EM 385-1-1 requires designated competent and qualified persons for specific activities. These individuals must have the training, experience, and authority to identify hazards and take corrective action.
Hot Work Supervisor
Must be designated in writing by the contractor. Responsible for authorizing hot work permits, verifying fire prevention controls, ensuring fire watch is posted, and confirming atmospheric monitoring in enclosed spaces. Must have training in fire prevention, hot work procedures, and emergency response.
EM 385-1-1 Reference: Section EM 385-1-1 Section 10.B.02
Fire Watch
Trained in fire extinguisher use and fire watch duties. Must maintain continuous visual observation of the hot work area. Must know how to activate the fire alarm and emergency notification system. Cannot perform other duties while on fire watch.
EM 385-1-1 Reference: Section EM 385-1-1 Section 10.B.03
Qualified Welder
Must hold current welding certifications for the specific process and position being performed (per AWS D1.1 or applicable code). Must be trained in the hazards of welding fumes, electrical safety, and fire prevention.
EM 385-1-1 Reference: Section EM 385-1-1 Section 10.B.01
Equipment, Training & Inspection Requirements
Required Equipment
Training Requirements
- OSHA 30-Hour Construction Safety (required for supervisors on USACE projects)
- Site-specific safety orientation per EM 385-1-1 Section 01.A.13
- Hot work and fire prevention training per NFPA 51B
- Welding safety training including fume hazards, electrical safety, and PPE use
- Fire extinguisher training (hands-on with live fire or approved simulator)
- Respiratory protection training and fit testing per 29 CFR 1910.134
- Hazard Communication training for welding consumables and compressed gases
- Confined space entry training if welding will occur in permit-required confined spaces
- Fall protection training if welding at heights above 6 feet
Inspection Requirements
- Daily inspection of all welding equipment, cables, connections, and ground clamps before first use each shift
- Pre-use inspection of compressed gas cylinders, regulators, hoses, and flash-back arrestors
- Atmospheric monitoring before and during welding in enclosed or semi-enclosed areas
- Fire extinguisher monthly inspection per NFPA 10; documented on inspection tags
- Welding machine grounding verification and GFCI testing
- Weekly documented safety inspection of hot work operations by site safety representative
- Verification of welder certification currency for process and position being performed
- Post-fire-watch area inspection documented on hot work permit
Applicable OSHA Standards
29 CFR 1926.351
Arc Welding and Cutting
Construction-specific requirements for manual and semi-automatic arc welding equipment, grounding, electrode holders, cable splicing, and equipment maintenance.
29 CFR 1926.352
Fire Prevention (Welding and Cutting)
Requires fire watchers when welding near combustibles that cannot be relocated. Specifies combustible clearance distances and fire watch duration requirements.
29 CFR 1926.353
Ventilation and Protection in Welding, Cutting, and Heating
Mechanical ventilation requirements for welding in confined spaces and enclosed areas. Specifies minimum air flow rates and conditions requiring respiratory protection.
29 CFR 1910.252
General Requirements for Welding, Cutting, and Brazing
General industry standard covering fire prevention, personnel protection, health hazards, ventilation requirements, and special applications.
29 CFR 1926.354
Welding, Cutting, and Heating in Way of Preservative Coatings
Requirements for hot work on surfaces coated with toxic preservatives. Requires stripping of coatings, ventilation, and respiratory protection.
Required Personal Protective Equipment
Frequently Asked Questions
What is the difference between a welding AHA and a welding JSA?
An AHA is the USACE/DoD-specific format required under EM 385-1-1 for government construction contracts. It includes Risk Assessment Codes (RAC), Definable Features of Work (DFOW) identification, EM 385-1-1 section references, competent person designations, and equipment/training/inspection requirements. A JSA is the more common commercial format that focuses on step-by-step hazard identification and controls. The AHA is a more comprehensive document that incorporates the JSA approach within a broader safety management framework.
How long must fire watch continue after welding on a USACE project?
EM 385-1-1 requires fire watch for a minimum of 30 minutes after hot work is completed, consistent with NFPA 51B. However, many USACE districts and contracting officers require 60 minutes, and this extended duration is considered best practice. The specific requirement should be documented in the Accident Prevention Plan (APP) and each hot work permit. The fire watch person must remain at the location with extinguishing equipment and cannot perform other duties during the watch period.
Who is the competent person for hot work under EM 385-1-1?
EM 385-1-1 requires a designated competent person who is responsible for authorizing hot work permits and ensuring all fire prevention controls are in place. This person must be designated in writing by the contractor and must have the training, knowledge, and authority to identify and correct hot work hazards. The hot work supervisor, fire watch, and qualified welder are distinct roles, though one person may hold multiple designations if qualified.
What atmospheric monitoring is required before welding in enclosed areas?
Before welding in any enclosed or semi-enclosed area, atmospheric monitoring must confirm oxygen levels between 19.5% and 23.5%, flammable gas concentrations below 10% of the Lower Explosive Limit (LEL), and the absence of toxic gases above permissible exposure limits. A calibrated 4-gas monitor (O2, LEL, CO, H2S) is the minimum instrument. Continuous monitoring is required throughout the welding operation. If the space meets the OSHA definition of a permit-required confined space, full confined space entry procedures apply.
What RAC rating should welding operations receive?
The initial uncontrolled RAC for welding and hot work typically rates as High (2), based on Critical severity (potential for permanent disability from burns, electrical shock, or fume exposure) and Likely probability (these hazards are consistently present during welding). With full implementation of engineering controls, administrative procedures, fire prevention measures, and PPE, the residual RAC should reduce to Low (4-5). If the residual RAC cannot be reduced to Medium (3) or below, additional controls or engineering alternatives to hot work should be evaluated.