S A F E T Y M O D E L S TAG E 3 — C O N T rO L L I N G H A Z A r D S : S A F E WO r K P r AC T I C E S
A crew of 7 workers was painting a 33-foot sign at a shopping mall. The crew used tubular welded frame scaffolding that was 31 feet tall and made up of several tiers. The sign was p a r t i a l l y p a i n t e d w h e n t h e c r e w w a s i n s t r u c t e d t o m o v e t h e s c a f f o l d i n g s o t h a t c o n c r e t e c o u l d b e poured for an access road. The crew moved the scaffolding 30 feet without disassembling it. An overhead powerline was located about 10 feet away from the scaffolding. After the concrete hardened, the workers lifted the scaffolding to move it back to the sign. The top tier came loose, fell, and contacted the powerline. All seven workers were knocked away from the scaffolding. Two died; five were hospitalized.
You must take certain precautions when working with scaffolding.
Scaffolding should not be moved until all potential safety hazards are identified and controlled. In this case, the scaffolding should have been taken apart before it was moved.
Locking pins must be used to secure tiers to one another.
Always make sure you have enough time to complete your assignment safely. If you are rushed, you may be more likely to take deadly short-cuts (such as failing to dismantle scaffolding before moving it).
Employers must have a written safety program that includes safe work procedures and hazard recognition.
❑ Do not do any tasks that you are not trained to do or that you do not feel comfortable doing!
A company was contracted to install wiring and fixtures in a new office complex. The third floor was being prepared in a hurry for a new tenant, and daily changes to the electrical system blueprints were arriving by fax. The light fixtures in the office were mounted in a metal grid that was fastened to the ceiling and properly grounded.
A 23-year-old male apprentice electrician was working on a light fixture when he contacted an energized conductor. He came down from the fiberglass ladder and collapsed. Apparentl , he had contacted the “hot” conductor while also in contact with the metal grid. Current passed through his body and into the grounded grid. Current always takes a path to ground. In this case, the worker was part of that path.
He was dead on arrival at a nearby hospital. Late , an investigation showed that the victim had cross- wired the conductors in the fixture by mistake. This incorrect wiring allowed electricity to flow from a live circuit on the completed section of the building to the circuit on which the victim was working.
Below are some safety procedures that should have been followed in this case. Because they were ignored, the job ended in death.
Before work begins, all circuits in the immediate work area must be shut off, locked out, and tagged out—then tested to confirm that they are de-energized.
Wiring done by apprentice electricians should be checked by a journeyman.
A supervisor should always review changes to an original blueprint in order to identify any new hazards that the changes might create.