Dynamic risk assessment
A dynamic risk assessment is the continuous, on-the-spot check of hazards as conditions change during a job. It is how a competent worker reacts when the site is not as planned. It does not replace the written risk assessment; it fills the gap between the paperwork and reality.
Written vs dynamic
| Written (RAMS) | Dynamic | |
|---|---|---|
| When | Before the job | During the job, whenever something changes |
| Who | Supervisor or business owner | Everyone on site |
| Covers | Foreseeable hazards of the planned work | New or changed hazards: weather, other trades, unexpected services, members of the public |
| Record | Always for 5+ employees; expected by clients | Not always written, but significant changes should be recorded |
Examples on site
- Wind picks up while you are on a roof: stop handling sheet materials.
- You uncover a cable that is not on the drawings: stop, isolate the area, treat it as live.
- The client's children are playing near the skip: set up a barrier before carrying on.
- Another trade starts grinding next to you: agree a sequence or move.
- You find suspected asbestos: stop work in that area and get it tested.
A simple 5-step method
- Stop and look at what has changed.
- Think: who could be hurt and how?
- Control: can you remove the hazard, or do you need to change the method?
- Communicate: tell your supervisor and anyone affected.
- Record any significant change and update the RAMS before the next shift.
Keep the written part up to date. When a dynamic assessment changes the method, edit the RAMS in RAMS Maker and re-issue the PDF in a couple of minutes. Pro saves every version in your library.
Make RAMS See ProQuestions
Is a dynamic risk assessment a legal requirement?
The law requires suitable and sufficient risk assessment and a safe system of work. Reacting to changing conditions is part of that, but there is no separate legal form called a dynamic risk assessment.
Where does the term come from?
It was developed by fire and rescue services for emergency incidents and is now used widely in construction, care and maintenance work.
Can a dynamic risk assessment replace RAMS for small jobs?
No. Planned work still needs a risk assessment, and clients will still ask for RAMS.
Checked against HSE guidance on risk assessment (INDG163), October 2026. Related: What are RAMS? · hierarchy of control.