3.2 Job Hazard Analysis (JHA) & Risk Matrix Evaluation

Job Hazard Analysis (JHA)—also commonly referred to as Job Safety Analysis (JSA)—is a fundamental risk assessment tool used in construction safety management. A JHA focuses on the relationship between the worker, the task, the tools, and the work environment to integrate health and safety principles into specific operational procedures.

In accordance with DOLE Department Order No. 13-98 (DO 13-98), contractors must conduct task-specific risk assessments prior to initiating high-risk construction operations. JHA serves as the primary mechanism for breaking down complex construction jobs into manageable parts, identifying potential hazards associated with each step, and establishing effective control measures before work begins.

The 5-Step Job Hazard Analysis (JHA) Execution Process

Performing an effective JHA requires a structured, multi-step approach involving the Safety Officer, project engineers, site foremen, and experienced trade workers.

Step 1: Select the Job/Task to Analyze

While ideally every construction task should have a JHA, priority must be given to:

• Jobs with high historic accident or near-miss rates.
• High-risk operations (e.g., deep excavation, tower crane assembly, hot work, confined space entry).
• Non-routine or newly introduced construction tasks.
• Jobs involving multi-trade coordination or complex heavy machinery.

Step 2: Break the Job into Sequential Steps

List the basic steps of the job in chronological order from start to finish. Guidelines for step breakdown include:

• Maintain an optimal detail level: aim for 5 to 10 logical sequential steps per job.
• Avoid making steps too broad (e.g., "erect scaffold") as broad descriptions obscure specific hazards.
• Avoid making steps overly detailed (e.g., "lift left foot, step onto first rung") as excessive detail makes the document unreadable.

Step 3: Identify Hazards for Each Step

For every single step identified, critically examine what could go wrong by asking targeted diagnostic questions:

• Is the worker exposed to fall hazards, pinch points, or falling objects?
• Is there potential contact with live electrical lines or toxic chemical fumes?
• Can awkward body postures or excessive manual lifting cause musculoskeletal strain?

Step 4: Formulate Control Measures

Develop specific, actionable control measures for each identified hazard by applying the Hierarchy of Controls (Elimination, Substitution, Engineering Controls, Administrative Controls, and PPE). Avoid vague statements such as "be careful" or "use caution"; instead, prescribe exact actions (e.g., "Install double guardrails and anchor safety harness to tested lifeline").

Step 5: Review, Approve, and Communicate

Before executing the job:

• Review the completed JHA with site foremen and workers during the pre-shift Toolbox Talk.
• Obtain formal approval from the Safety Officer and Construction Project Manager.
• Revise the JHA immediately whenever site conditions, equipment, or work scopes change.

Quantitative Risk Assessment & The 5×5 Risk Matrix

Once hazards are identified through JHA, their risk levels must be quantified to prioritize corrective actions. In DOLE HIRAC methodology, Risk is mathematically defined as:

$\text{Risk Score} = \text{Severity (S)} \times \text{Likelihood (L)}$

Likelihood Rating Scale (1 to 5)

• 1 - Rare / Improbable: Highly unlikely to occur during the project lifecycle.
• 2 - Remote / Unlikely: Unlikely, but could occur under exceptional circumstances.
• 3 - Occasional / Possible: Might occur at some point during normal construction operations.
• 4 - Probable / Likely: Will probably occur in most construction environments.
• 5 - Frequent / Almost Certain: Expected to occur regularly or continuously.

Severity Rating Scale (1 to 5)

• 1 - Negligible: Minor first-aid injury; no lost work days; negligible material damage.
• 2 - Minor: Medical treatment injury; minor short-term disability; minor localized damage.
• 3 - Moderate: Lost-time injury; reversible severe impairment; moderate equipment damage.
• 4 - Major: Single fatality or permanent disabling injury; major structural damage.
• 5 - Catastrophic: Multiple fatalities; widespread structural collapse; catastrophic site failure.

Standard 5×5 Risk Evaluation Matrix Table

Risk Level Classification & Action Thresholds

• Low Risk (Score 1 – 4): Acceptable risk. Manage through routine standard operating procedures, standard site induction, and basic PPE.
• Medium Risk (Score 5 – 9): Tolerable risk. Requires specific controls documented in JHA; supervisory monitoring required; action must be taken within a specified timeframe.
• High Risk (Score 10 – 15): High priority hazard. Work must NOT proceed until detailed JHA is approved and enhanced engineering/administrative controls are implemented.
• Extreme Risk (Score 16 – 25): Unacceptable risk. Work must be stopped immediately. Operation cannot commence under any circumstances until risk score is reduced to Low or Medium level.

Prioritizing High-Risk Operations for Work Permits (PTW)

Tasks evaluated with High or Extreme risk scores mandate a formal Permit-to-Work (PTW) system. A PTW is a documented authorization protocol that ensures high-risk construction activities undergo physical verification of safety precautions before execution.

Mandatory PTW High-Risk Activities in Construction:

1. Hot Work Operations: Welding, oxy-fuel cutting, or grinding in areas containing combustible materials.
2. Confined Space Entry: Entering storage tanks, subterranean manholes, sewers, or unventilated shafts.
3. Work at Heights & Critical Lifts: Operations above 2 meters without standard platforms, or crane lifts exceeding 75% of rated load capacity.
4. Deep Excavation & Trenching: Excavations over 1 meter deep (Rule 1413) or adjacent to existing building foundations.
5. Energized Electrical Splicing & Lockout/Tagout (LOTO): Maintenance work performed on primary power systems.