What Is a Dynamic Risk Assessment (DRA)?
How to identify risks in real time and keep your construction site safe
A Dynamic Risk Assessment is a real-time evaluation of hazards carried out on the spot, usually by site workers, supervisors, and subcontractors. Unlike a standard written risk assessment completed before work begins, a DRA helps workers respond to unexpected hazards, changing site conditions, and evolving risks during the job.
In the construction sector—where environments shift daily, and multiple trades work in close proximity Dynamic Risk Assessment is essential for preventing accidents, delays, and costly safety breaches.
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Why Dynamic Risk Assessments Are Important in Construction
1. Construction Sites Change Constantly
Weather, plant movement, deliveries, ground conditions and access routes can change in minutes. A DRA ensures risks are reassessed when conditions shift.
2. Workers Face Unplanned Hazards
Unexpected hazards include:
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New excavations
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Temporary power cables
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Materials stored incorrectly
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MEWPs or forklifts operating nearby
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Slips, trips and uneven ground
A written risk assessment won’t always cover these, but a DRA will.
3. Compliance With UK Legislation
The Health and Safety at Work Act 1974 and Management of Health and Safety at Work Regulations 1999 require employers to manage risk as it arises. DRAs support these legal duties.
4. Reduces Accidents and Delays
By empowering workers to pause, think, and react, DRAs significantly reduce the chance of injury, project delays, insurance claims and HSE notices.
Who Should Carry Out a Dynamic Risk Assessment on Site?
A DRA can be performed by:
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Site managers
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Supervisors
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Tradespeople
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Plant operators
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Subcontractors
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Anyone who encounters a change in conditions
It’s important that every worker is trained to recognise hazards and understands they have the authority to stop work immediately if they believe new risks have emerged.
How to Carry Out a Dynamic Risk Assessment
Step 1: Stop and Observe the Task
Pause before starting the activity. Look at the area, equipment, and people nearby.
Step 2: Identify New or Unexpected Hazards
Common construction examples:
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Unstable loads
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Missing edge protection
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Live services exposed
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Unsafe weather conditions (wind, rain, heat)
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New contractors working overhead
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Confined space risks
Step 3: Evaluate the Risk Level
Ask:
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How likely is an accident?
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What is the potential severity?
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Who could be harmed?
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Do control measures already exist?
Step 4: Implement Controls Immediately
Typical controls include:
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Changing the access route
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Stopping plant movements
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Using a banksman
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Wearing additional PPE
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Delaying the task
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Getting a supervisor’s approval
Step 5: Continue or Stop the Task
If risks cannot be controlled safely: STOP WORK.
Report to a supervisor and update the formal RAMS if necessary.
Dynamic Risk Assessment vs. Standard Risk Assessment
| Standard (Written) Risk Assessment | Dynamic Risk Assessment (On-the-Spot) |
| Completed before work starts | Completed during the task |
| Based on planned hazards | Based on real-time hazards |
| Required by law | Supports legal compliance |
| Usually done by managers | Done by anyone on site |
| Good for predictable risks | Essential for unexpected risks |
Both are needed. A DRA does not replace RAMS—it strengthens them.
Best Practices for Dynamic Risk Assessment in Construction
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Train all workers in hazard awareness
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Encourage a “Stop Work Authority” culture
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Keep RAMS up to date
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Hold daily briefings or toolbox talks
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Use simple DRA checklists
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Ensure supervisors support DRAs, not rush them
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Use technology (apps, mobile checklists, AI-based risk monitoring)
Dynamic Risk Assessment Checklist
Before starting a task, ask:
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Are conditions the same as planned?
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Has anything changed since the RAMS briefing?
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Are other trades affecting the area?
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Is my equipment safe and suitable?
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Are weather or ground conditions safe?
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Do I need extra PPE or controls?
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Should I stop and report before continuing?
Frequently Asked Questions (FAQs)
Is a Dynamic Risk Assessment a legal requirement?
Not specifically—but the law requires employers to manage risks as they arise, making DRAs essential for compliance.
Do DRAs replace RAMS?
No. DRAs support RAMS by covering unexpected hazards.
Who can perform a DRA?
Anyone on site—workers, operators, supervisors, and contractors.
Should DRAs be documented?
Yes, when practical. Apps and mobile forms make this simple.
Conclusion: Why Your Construction Business Needs Dynamic Risk Assessment
Dynamic Risk Assessments keep your workers safe, your projects compliant, and your business protected. In a fast-changing environment like construction, they are a vital line of defence against accidents.
Combined with AI tools, DRAs help you:
✔ reduce incidents
✔ improve productivity
✔ meet UK safety standards
✔ protect your workforce
✔ strengthen your RAMS
