Hazard Identification and the Hierarchy of Controls

What Is Hazard Identification?

Before any work begins on a construction site, someone must look at the work area with a trained eye and ask: What here could hurt someone? That structured look is called a pre-task hazard assessment (also called a job hazard analysis, or JHA). It is not optional — OSHA's General Duty Clause requires employers to provide a workplace free from recognized hazards that are causing or likely to cause death or serious physical harm. A hazard log is the written record of that assessment.

Hazards on construction sites generally fall into a few broad categories:

• Physical hazards – trip and fall risks, falling objects, unguarded edges, noise, heat
• Chemical hazards – unlabeled containers, solvents, dust, paint fumes
• Electrical hazards – unguarded extension cords, missing ground-fault protection, proximity to overhead lines
• Ergonomic hazards – repetitive lifting, awkward postures, vibration
• Struck-by / caught-in hazards – moving equipment, pinch points, collapsing materials

Recognizing a hazard is only the first step. You must also decide what to do about it, and do so in the right order.

The Hierarchy of Controls

The hierarchy of controls is a ranked list of strategies for reducing risk. Controls at the top of the list are most effective because they remove the hazard or reduce exposure without relying on worker behavior. Controls at the bottom are least effective because they depend on the worker to act correctly every time. OSHA and NIOSH both endorse this hierarchy.

1. Elimination – Physically remove the hazard from the workplace. Example: if lumber with protruding nails is scattered on a walking path, remove it entirely. This is the most effective control.

2. Substitution – Replace the hazardous material or process with something less dangerous. Example: use water-based paint instead of solvent-based paint to reduce vapor exposure.

3. Engineering Controls – Use physical means to isolate workers from the hazard without removing the hazard itself. Example: install a guardrail system on an open-sided platform; add a ground-fault circuit interrupter (GFCI) to an electrical circuit. Engineering controls do not rely on worker behavior.

4. Administrative Controls – Change the way work is done through policies, procedures, schedules, or training. Example: limit the time workers spend in high-noise areas; require a permit-to-work system before entering a confined space; post warning signs around a hazardous area. These controls are only as good as the people who follow them.

5. Personal Protective Equipment (PPE) – Provide workers with devices that protect the body when exposure cannot be eliminated by other means. Example: hard hats, safety glasses, hi-vis vests, gloves, hearing protection. PPE is always the last resort, not the first. It does nothing to reduce the hazard — it only reduces injury if it fits correctly, is worn consistently, and is maintained properly.

Why Cost and Effort Rise as You Move Down

It may seem backward, but the most effective controls — elimination and substitution — are often the cheapest in the long run because they prevent the hazard from existing. Engineering controls require upfront capital (guardrails, ventilation systems, GFCIs) but run with little ongoing cost. Administrative controls require continuous training and supervision. PPE must be purchased, fitted, inspected, and replaced repeatedly, and if a worker forgets to wear it, protection disappears instantly. A competent person always tries to apply the highest feasible level of control first.

Conducting a Pre-Task Hazard Assessment

A systematic walkthrough follows these steps:

1. Put on your own PPE first. Before entering any work area, don required PPE — at minimum a hard hat, safety glasses, and hi-vis vest for a general construction area.

2. Walk the entire area slowly. Look up (overhead hazards), at eye level (struck-by, chemical), and down (trip hazards, floor openings).

3. Record every hazard you observe on the hazard log form — describe it precisely (location, nature, affected task).

4. Categorize each hazard (physical, chemical, electrical, etc.).

5. Assign a control from the hierarchy. Ask: can this hazard be eliminated? If not, can it be substituted? Work down the list until you find the highest feasible level.

6. Assign responsibility and a timeline for correcting each hazard.

7. Review findings with the crew before work starts.

Safety Points for the Walkthrough Activity

• Never bypass PPE requirements even in a training environment. If the mock site requires a hard hat, wear it — building the habit matters.
• Lockout/tagout (LOTO): if you ever observe energy-isolation needs during a real assessment, the area must be made safe before anyone enters. In today's simulated walk, treat all planted hazards as real.
• Report immediately: if you spot a hazard during the walk that was not planted (a real hazard), stop and notify the instructor before proceeding.
• Do not touch unlabeled containers — treat them as unknown chemicals until verified.

Using Your Hazard Log on the Job

The hazard log you complete today is the same type of document used daily on NCCER- and CMAA-recognized projects. Project managers rely on these records to demonstrate due diligence, meet contract safety requirements, and support OSHA recordkeeping. A well-maintained hazard log protects workers and protects the company.