Scaffold ___ Are the Workers Qualified To Design Scaffolds (Fill in the Blank)?
The missing word is "designers." Scaffold designers are the workers qualified to design scaffolds. Under OSHA 1926.451, a scaffold must be designed by a qualified person, and certain types (like outrigger scaffolds) require a registered professional engineer.
The answer
The sentence completes as: "Scaffold designers are the workers qualified to design scaffolds." The word that fills the blank is designers.
This comes straight from OSHA's scaffold standard, 29 CFR 1926.451(a)(6), which states that scaffolds and scaffold components must be designed by a qualified person and constructed and loaded in accordance with that design. So the specific role is a scaffold designer — but OSHA attaches a legal meaning to who is allowed to hold that role.
Qualified person vs. competent person
Students mix these two OSHA titles constantly, so here is the plain difference:
- Qualified person — someone who, by a recognized degree, certificate, professional standing, or extensive knowledge/training/experience, has demonstrated the ability to solve problems related to the work. The qualified person designs the scaffold and its loading.
- Competent person — someone capable of identifying existing and predictable hazards and who has authorization to take prompt corrective action. The competent person selects, supervises erection, trains, and inspects the scaffold — not designs it.
A memory hook: the qualified person figures out how it should be built (engineering/design judgment); the competent person watches whether it is safe right now (hazard authority on site). One person can hold both titles, but the roles are legally distinct.
Which scaffolds need a professional engineer
Most standard scaffolds only require a qualified person's design. But OSHA specifically requires a registered professional engineer (PE) to design several higher-risk configurations, including:
- Pole scaffolds over 60 feet in height (design by a registered PE).
- Tube-and-coupler scaffolds over 125 feet.
- Fabricated frame scaffolds over 125 feet.
- Outrigger scaffolds and the outrigger beams/counterweights.
- Bracket/masons' multi-point adjustable suspension and similar heavy or unusual systems.
So the correct chain of authority is: routine scaffold → qualified person designs it; tall or unusual scaffold → registered professional engineer designs it; on the job every day → competent person inspects it before each shift.
Why the other common blanks are wrong
If you were tempted to fill the blank with "erectors," "users," or "inspectors," those roles do not carry design authority. Erectors build to a design they are handed; users occupy the finished platform; inspectors (the competent person) check condition — none of them are, by title, the workers qualified to design. "Engineers" is close and correct only for the special PE cases above, but it is too narrow to be the general answer, because OSHA lets any qualified person design an ordinary scaffold without being a licensed engineer. That is why designers is the best fill-in-the-blank word here.
The practical takeaway for an exam: memorize that design = qualified person, inspection/hazard control = competent person, and tall/outrigger/unusual scaffolds = registered professional engineer.
- 1
Is this a routine scaffold within OSHA height limits?
If yes, a qualified person may design it. A qualified person has the training, credentials, or experience to solve scaffold-design problems.
- 2
Is it an outrigger scaffold, or over the height limits (e.g., pole >60 ft, frame/tube-and-coupler >125 ft)?
- 3
Who inspects it on site before each shift?
Frequently asked
What is a qualified person under OSHA scaffold rules?
A qualified person is someone who, by degree, certificate, professional standing, or extensive knowledge, training, and experience, has demonstrated the ability to solve problems related to scaffolding. Under 1926.451, this person designs the scaffold and its loading.
What is the difference between a competent and qualified person?
A qualified person designs the scaffold and solves engineering-type problems. A competent person identifies existing and predictable hazards on site and has authority to take prompt corrective action, including inspecting the scaffold before each work shift. The same individual can sometimes hold both roles.
Which scaffolds require a professional engineer?
OSHA requires a registered professional engineer to design pole scaffolds over 60 feet, tube-and-coupler and fabricated frame scaffolds over 125 feet, outrigger scaffolds and their beams/counterweights, and certain masons' multi-point adjustable suspension scaffolds.
Who must design scaffolds per OSHA?
Per 29 CFR 1926.451(a)(6), scaffolds and their components must be designed by a qualified person and built and loaded according to that design. Higher-risk or unusually tall scaffolds must be designed by a registered professional engineer.
What is OSHA standard 1926.451?
1926.451 is OSHA's general requirements standard for scaffolds in construction. It covers capacity, platform construction, criteria for supported and suspension scaffolds, access, fall protection, and the requirement that a qualified person design the scaffold.