OSHA 10 Domain Review: Construction Safety Essentials

Why OSHA 10 Matters on the Job

The OSHA 10-Hour Construction Outreach course teaches workers to recognize, avoid, and control the most common construction hazards. Completing the course earns you a wallet card issued through the U.S. Department of Labor's Outreach Training Program. Many contractors require it before workers set foot on a jobsite. The credential shows that you understand your rights and the employer's duties under the Occupational Safety and Health Act of 1970.

The Leading Cause: Falls

Falls are the single largest cause of construction fatalities. OSHA's fall protection standard (Subpart M of 29 CFR Part 1926) requires protection when workers are at or above six feet on a construction site. The three accepted methods are guardrail systems, safety net systems, and personal fall arrest systems (PFAS). A PFAS includes a full-body harness, a lanyard or self-retracting lifeline, and an anchor point rated to withstand the fall force. Workers must inspect harnesses before each use and remove any harness that shows cuts, fraying, or deformed hardware.

Apply the hierarchy of controls to falls: eliminate the fall hazard by doing work at ground level when possible; substitute with a safer method; engineer in guardrails; use administrative controls such as warning-line systems for low-slope roofs; and finally rely on PPE (personal fall arrest) as the last line of defense.

Scaffolding Safety

Scaffolding accidents injure thousands of workers each year. OSHA's scaffolding standard (Subpart Q) requires that supported scaffolds be capable of supporting their own weight plus at least four times the maximum intended load. Platforms must be fully planked, and guardrails are required on all open sides and ends when the scaffold is ten feet or more above a lower level. A competent person must inspect the scaffold before each work shift and after any event that could affect its structural integrity.

Electrical Safety

Electrical hazards include shock, arc flash, and electrocution. OSHA's electrical standards (Subpart K) require ground-fault circuit interrupter (GFCI) protection for all 120-volt, single-phase, 15- and 20-ampere receptacle outlets on construction sites. Overhead power line safety requires maintaining safe clearance distances; when working near energized lines, always contact the utility owner before beginning work. Lockout/tagout (LOTO) procedures must be followed whenever servicing or maintaining electrical equipment: de-energize the source, lock it out, tag it, and verify it is de-energized before touching any part of the system.

The Fatal Four: Struck-By and Caught-In/Between

OSHA groups the top construction killers as the Fatal Four: falls, struck-by, caught-in/between, and electrocution. Together they account for the majority of construction fatalities each year.

Struck-by hazards occur when a flying, falling, swinging, or rolling object hits a worker. Hard hats protect against falling objects; high-visibility vests protect workers near vehicle traffic. Workers should never stand in the swing radius of heavy equipment.

Caught-in/between hazards occur when a worker is caught, compressed, or crushed between objects. Trenching is a classic example: cave-ins can bury a worker in seconds. OSHA requires protective systems—sloping, shoring, or trench boxes—for excavations five feet or deeper (and for any depth when the competent person judges the soil is unstable).

Personal Protective Equipment (PPE)

PPE is the last line of defense in the hierarchy of controls. Employers must assess the workplace for hazards, select appropriate PPE, and train workers in its use and limitations. Common construction PPE includes hard hats (ANSI Class E for electrical work areas), safety glasses or goggles, gloves, steel-toed footwear, high-visibility vests, hearing protection, and respiratory protection. PPE must fit properly and be inspected before each use.

Hazard Communication (HazCom)

OSHA's Hazard Communication Standard (HCS), aligned with the Globally Harmonized System (GHS), requires that workers who use hazardous chemicals have access to Safety Data Sheets (SDS) for each product. SDSs must be readily accessible during the work shift. Labels on containers must display a signal word (DANGER or WARNING), pictograms, and hazard statements. Employers must train workers on the SDS format and how to read labels before exposing them to hazardous chemicals.

Worker Rights

The OSH Act gives workers three fundamental rights: the right to a safe workplace; the right to receive information and training about hazards; and the right to report unsafe conditions to OSHA without fear of retaliation. Workers may request an OSHA inspection, and OSHA will keep their identity confidential if asked. Employers may not discharge or discriminate against workers for exercising their OSHA rights. Workers can file a complaint with OSHA if they believe they have been retaliated against.

Preparing for the Quiz

The OSHA 10 outreach format uses multiple-choice questions tied to these focus areas. As you work through practice questions, always ask: What is the hazard type? Which standard category applies? What is the correct control, in order from the hierarchy? Log every missed question by focus area so you know exactly where to focus your review. A score of 70% or higher on the practice quiz means you have the foundational knowledge needed for the real course completion assessment.