From 123 to 123+

HART decontamination officer

A new initial operational response (IOR) to a CBRN (chemical, biological, radiological and nuclear) incident has been created, following developments in scientific understanding and lessons identified from exercises and real incidents. The current step 123 protocol for assessing the likelihood of hazardous materials at an incident has been amended and an aide memoire will be attached to your payslips this month. 

Step 123 is a way of identifying potential chemical incidents by the number of patients incapacitated with no obvious reasons;

One person – approach using standard protocols
Two people – approach with caution
Three people in close proximity – use caution and now follow the plus protocol

The new guidance is for call handlers and responders who are first on scene and is now known as step 123 plus. In a CBRN incident all emergency services will now follow these principles: 

  • Evacuation

From a distance, you should encourage walking casualties to move away from the scene of contamination; this should be carried out as a priority. Casualties should be moved to an area upwind and ideally uphill of the incident. 

  • Communication and advice

It is important to clearly and continually communicate to casualties throughout the incident, including what you know about the incident, what you are doing to help affected people, and how they can help themselves. 

  • Disrobe

Instructing a casualty to disrobe/undress is a critical step in the decontamination process. This is highly effective at reducing exposure to CBRN materials. Consideration should be given to ensuring the welfare and dignity of casualties as far as possible. 

  • Decontamination

Improvised decontamination on all disrobed casualties is a priority and this should be carried out by the casualties themselves with instruction from the responder, who must remain at a safe distance. Dry decontamination, which should be considered the default process, is the use of dry absorbent material such as paper tissue or cloths to blot and rub the exposed skin. Wet decontamination, only to be used if signs and symptoms of caustic substance, is the use of water from any available source such as taps, showers, hose-reels, sprinklers, etc. 

As always, the first responders must not put themselves in danger and these steps are to be carried out by the casualties themselves while responders stay a safe distance away.

By evacuating, effective disrobing and decontaminating the casualties, ideally within 15 minutes of exposure, the vast majority of the skin contaminant will be removed. 

The aide memoire is also available as a digital version; you can also complete the e-learning package and a video about the protocol will be available on East24 very soon. This work has been carried out by JESIP (Joint Emergency Services Interoperability Programme) and our colleagues in the other emergency services, and acute trusts will be following the same protocol. 

If you have any questions or want more information, please email

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