Job Hazard Analysis: Ductwork installation

A general example for this task. Your JHA should reflect your crew, equipment and site — review it with a competent person before work starts.

Steps, hazards and controls

1. 1. Unload and stage duct sections, fittings, and insulation rolls in the work area.

   • Cuts from sharp sheet metal edges.Medium
     • Carry duct by the seams or with the edges facing away from your body.
     • Stack duct on dunnage or a cart, not loose on the floor.
     • Wear cut-resistant gloves when handling sheet metal.
   • Back strain from lifting long or bulky duct and boxed fittings.Medium
     • Use a dolly or cart for heavy boxes and long runs.
     • Use a two-person carry for sections over 10 ft or over 50 lb.
     • Lift with your legs and keep the load close to your body.
   • Tripping over material stacked in walkways.Low
     • Stage material out of walkways and exit paths.
     • Keep stacks low and stable.

2. 2. Set up access: 6-ft or 8-ft fiberglass stepladder, rolling scaffold, or scissor lift.

   • Falls from ladders, scaffolds, or lifts.High
     • Use a scissor lift or rolling scaffold with guardrails instead of a ladder for long overhead runs.
     • Inspect ladders before use; tag out and remove any with cracked rails, bent braces, or missing feet.
     • Open stepladders fully with spreaders locked; never stand on the top cap or top step.
     • On rolling scaffolds, lock all casters, install full guardrails, and never ride it while it moves.
   • Scissor lift or scaffold tipping on uneven floors, holes, or ramps.High
     • Walk the floor first; cover or barricade floor openings and remove debris.
     • Do the pre-use inspection on the lift and test the controls before going up.
     • Stay within the lift's rated load and do not drive it elevated near edges or slopes.

3. 3. Lay out and install hangers: drill anchors or attach to joists, then hang threaded rod or strap.

   • Silica dust from drilling into concrete deck or block.High
     • Use a rotary hammer with a built-in dust shroud or hollow bit connected to a HEPA vacuum.
     • Follow the company silica exposure control plan; keep other workers out of the dust area.
     • Clean dust with the HEPA vacuum; never dry sweep or blow it with compressed air.
   • Debris and dust falling into eyes when drilling overhead.Medium
     • Position yourself to the side of the hole, not directly under it.
     • Wear safety goggles or glasses with side shields when drilling overhead.
   • Drilling into hidden electrical conduit, cable, or piping.Medium
     • Check plans and look for conduit, cable, and pipe before drilling.
     • Use double-insulated or grounded tools with a GFCI on the cord.
   • Tools, anchors, and rod falling on workers below.Medium
     • Barricade or cone off the area under overhead work.
     • Keep anchors and fasteners in a pouch or bucket, not loose on the platform.
     • Wear a hard hat in the work area.

4. 4. Cut and fit duct on site with snips, a nibbler, or a reciprocating saw; drill and screw seams.

   • Lacerations from cut sheet metal and burrs.High
     • Clamp the duct or set it on a bench before cutting; do not hold it on your knee.
     • Deburr or fold sharp edges right after cutting.
     • Wear cut-resistant gloves and long sleeves.
   • Injury from power tools: kickback, missing guards, damaged cords.Medium
     • Inspect tools and cords before use; remove damaged tools from service.
     • Keep guards in place and unplug or remove the battery before changing blades or bits.
   • Flying metal chips and noise from cutting.Medium
     • Cut in a designated area away from others.
     • Wear safety glasses at all times and earplugs when using saws or nibblers.

5. 5. Lift duct sections into place and secure them to hangers.

   • Falling while reaching or lifting duct from a ladder or lift.High
     • Move the ladder or lift instead of overreaching; keep your belt buckle between the rails.
     • Keep both feet on the lift platform floor; never climb the guardrails.
     • Use a duct lift or a second worker to raise long sections; do not carry duct up a ladder.
   • Duct section dropping or swinging and striking workers.Medium
     • Support the section on temporary straps until all hangers are tight.
     • Keep the area below barricaded and call out before lifting.
   • Pinched fingers between duct sections or at hangers.Low
     • Keep hands on the outside of joints while sliding sections together.
     • Wear work gloves.

6. 6. Seal joints with mastic or foil tape and wrap duct with fiberglass insulation, including work in attics.

   • Heat illness in hot attics or ceiling spaces.High
     • Schedule attic work for early morning when possible.
     • Use a portable fan to move air into the attic.
     • Drink water every 15 minutes, take breaks in the shade, and watch each other for dizziness or confusion.
   • Skin, eye, and throat irritation from fiberglass insulation.Medium
     • Cut insulation with a sharp knife on a board instead of tearing it.
     • Wear long sleeves, gloves, safety glasses, and an N95 dust mask.
   • Chemical exposure from duct mastic and sealants.Low
     • Read the SDS and container label before use.
     • Use water-based mastic when available and ventilate enclosed spaces.
     • Wear nitrile gloves and wash hands before eating.
   • Stepping through attic drywall between joists.High
     • Lay plywood or walk boards across joists and stay on them.
     • Use a work light so you can see the joists.

7. 7. Clean up scrap metal, screws, insulation, and dust; take down ladders and lifts.

   • Cuts and punctures from sheet metal scrap and loose screws.Medium
     • Put scrap in a dedicated scrap bin throughout the day, not at the end.
     • Use a magnetic sweeper for screws and wear cut-resistant gloves.
   • Slips and trips on debris and cords.Low
     • Coil cords and clear walkways before leaving the area.
     • HEPA vacuum dust; do not dry sweep concrete dust.