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Document: Hazardous Substances - General

Print date: 03/29/2010 17:18


Hazardous Substances - General



The primary role of the fire service at Hazardous Substances incidents is one of containment and control of the substance, and rescue and recovery of any persons exposed.  Dealing with hazardous substances at incidents is now a daily occurrence for many fire brigades.

Such substances may be in various physical forms of solids, liquids, and gas, and may be explosive, flammable, toxic, radioactive, corrosive or a combination of these.

They may be encountered in situ at a number of locations, e.g. schools, hospitals, farms, laboratories, factories etc., being either in use or stored.  They are also encountered in transit by road, rail or air.

Though industries using, storing and transporting hazardous substances are well regulated, the potential for a vast range of incidents to occur is high.

Exposure to hazardous substances leading to inhalation, absorption or ingestion may result in injury ranging from minor irritants to instant death.  The health effects may be immediate or short term (acute), or more delayed and long term (chronic).  It is important to note that many damaging effects to health from exposure to certain substances will not be obvious at the time of exposure.

Such incidents are usually time consuming with significant resource implications, and usually demand a multi-agency approach.

High risk sites and premises where hazardous substances are in use or stored, should be subject to Section 1(1)(d) inspections for familiarisation purposes.  Periodic multi-agency exercises should be organised to confirm any pre-planned procedures or inter-service liaison, and to practice and test existing information retrieval systems.





Chemicals – Explosive, oxidisers, toxic, infectious, corrosive, flammable, irritant, allergenic, carcinogenic, asphyxiant, and radioactive.


Severe injury, acute/chronic illness, death – firefighters and others - from exposure.  Damage to the environment.


Indirectly as a result of chemical process or reaction - Fire, explosion, boil over/slop over, extreme pressures/temperatures, electrocution and radiation.


Severe injury, death – firefighters and others.




Pre-Determined First Attendance

2 Pump Rescue Ladders

1 Specialist Hazardous Substances Officer


Dynamic Risk Assessment (DRA)

At hazardous Substance incidents, the safety of the public, brigade and other personnel is of the utmost importance.  Extreme care must be exercised in the initial assessment of hazards and risks.

Appliances must approach cautiously from upwind – keep a safe distance initially in case of sudden escalation of risk.

The Incident Commander must include the following considerations in the initial dynamic risk assessment.


What or who is at immediate risk – people, property or the environment, and to what extent?  This is essential as the initial control measures applied rely on information gathering which considers the level of risk to people and the environment against the risk to fire service personnel.

Exposure to unknown chemicals must be prevented until sufficient information is available to suitably assess the hazardous properties of the substance.


Is immediate evacuation required based on initial observations, e.g. a gas or fume cloud may be obvious, persons/animals may be obviously incapacitated, chemical corrosion or destruction may be in progress.


Establish liaison from the outset where possible with appropriate occupiers and agencies, to identify the substance(s).  Consult on-site personnel, vehicle placards, container labels, transportation documents and TREM-cards.


Identify the extent of the particular hazard – and what the potential development is during the incident, i.e. flammable, corrosive, explosive etc., and the quantities involved.


Determine whether the incident is static or dynamic, i.e. is the hazard confined to one area or is it likely to affect a large area via water courses, smoke, seepage, gas cloud, etc.


What are the implications of the weather conditions – wind strength and direction, rain, temperature etc.?

Based on the results of the initial DRA, it may be necessary to request additional resources without delay.  It is imperative that a safe rendezvous point (and a safe approach route if considered necessary) is designated in the assistance message.


Primary Actions by First Attendance

First attendance crews must resist the urge to ‘rush in’ and take immediate action.  To do so could easily render firefighters as casualties, therefore any decision to effect immediate rescues where required must be weighed against the potential of the risk.

The following actions are likely to be required in the early stages of confirmed hazardous substance incidents and will be prioritised depending on the DRA and circumstances at the time.


Secure the scene from upwind – isolate the hazardous area and establish appropriate cordons/restricted area, and deploy safety officers.


Establish and assist with evacuation of persons at risk to a safe area.


Request appropriate agencies to attend with a view to formulating a long - term plan of action.  This would normally include site representatives, scientific advisors (on-site or external), police consultative officers and the environment agency.


Ascertain substance characteristics and confirm any existing information using Substance Identification Number (where possible).  Scientific Advisors must be requested to attend in the following circumstances:-


Decontamination procedures are required to be implemented.


The substance cannot be identified.


A mixture of substances are involved.


Use appropriate information retrieval sources, e.g. Chemdata, Emergency Response Guide, scientific advisor etc. – Keep Fire Control informed.


Establish appropriate levels of PPE for all persons required to enter, any risk areas – use intrinsically safe equipment where flammable/explosive atmospheres may exist.


Establish emergency decontamination facilities as a minimum, particularly on occasions when actions are initiated before the arrival of the hazardous substances unit.


Deploy appropriate firefighting/cooling/smothering mediums in readiness to establish control.


Isolate potential ignition sources where possible.


Isolate process equipment – confirm the advantages in liaison with occupiers.  Assess the implications of any air conditioning or ventilation systems and isolate where necessary.


Initiate containment, dilution, absorption or dispersal procedures as agreed through liaison with the key agencies.


Command and Control

It is imperative that Incident Commanders initiate and maintain strict command and control over all personnel at hazardous substance incidents.


Initial operations must be limited until the hazards are confirmed and adequate resources are available.


Establish a safe Rendezvous Point for oncoming appliances - nominate a marshalling officer to facilitate the safe disposal of appliances and personnel via the Incident Commander.


Brief all service and non -service personnel frequently, and confirm understanding of instructions.


Establish close liaison between scientific advisors, hazardous substance officers and decontamination teams.


Fire Control must be informed of all developments and actions taken at the scene.


Restrict numbers of personnel working in the risk area to the minimum required to achieve the objectives.  All other personnel must be at a safe distance and upwind of the risk area.


Further Priority Considerations


Consult any contingency plans that may be available – on or off-site.


Establish adequate decontamination facility.


Limit the exposure time of personnel working in the risk area.


Prohibit eating, drinking, chewing and smoking in and around the risk area. Rest and refreshment areas at protracted incidents must be remote from the risk area, and washing facilities should be provided.

Provision of refreshments must be from outside the risk area to eliminate the risk of contamination.


Request Environmental Unit for specialist equipment likely to be required for containment, absorption etc.


Request attendance of a press officer to deal with any media coverage, and to facilitate public address if required, e.g. notification of large smoke plumes, gas clouds, large scale evacuation etc.


Establish liaison with the meteorological office via Fire Control for weather information, when an incident is large scale and likely to be protracted, and when the weather system has potential to increase the risks.  Wind direction in particular should be assessed frequently, to ensure that existing control measures will not be compromised.


Efforts must be made to contain or re-direct firefighting water run-off, in liaison with Environment Agency representatives.


Specialist materials such as neutralising agents must only be used and applied on the advice of scientific advisors.  When unavailable on site, requests for such materials must be via Fire Control.


Records of exposure must be completed for personnel that have worked in risk areas.


General Safety


Adequate safety officers must be nominated and frequently briefed on their specific tasks and development of the incident.


Ensure in the hours of darkness, that the site is adequately illuminated – and that egress routes from high – risk areas are kept clear.


All non-service personnel in risk areas must have adequate PPE, be aware of the evacuation signal and be accompanied by Fire Service personnel.


Personnel should not work inside a bund wall area.  Where this is absolutely unavoidable, a safety officer for watching brief must be nominated, and egress routes and points maintained.


Personnel should not be allowed to work on tank roofs unless absolutely necessary, and, if so, should work from aerial appliances where possible, and be equipped with fall arrest safety equipment.


At protracted incidents, an ambulance should be requested to standby in case of unexpected injury to personnel occurring.

Personnel must not work on top of tanks that are pressurised, on fire, or have been affected by fire.


When large chemical plants or pressurised systems and components are involved in fire, then firefighting should take place from behind adequate cover, using monitors and fixed installations.


Where fixed installations do not exist, and conditions may become extreme, branches should be lashed in position, and personnel kept at a safe distance.


Incident Conclusion

The police have ultimate responsibility for hazardous substance incidents where there is no potential for a fire situation to occur, though the Fire Service are equipped and trained to bring the incident under control.

It is imperative, therefore, that at all hazardous substance incidents, inter-service liaison is established and maintained throughout the incident.

Once the dynamic emergency stages of an incident have been successfully brought under control, the Incident Commander may hand the Duty of Care to the responsible person/authority.

The responsible persons or authorities can normally be ascertained via the Police, but for general information purposes, broad responsibilities are as follows:

Local Authority (Environmental Services)

School premises/playing fields, public premises, public open spaces, etc.


Their own private land.

Highways Agency

Motorways and major trunk roads.

County, metropolitan or Unitary Authority

Roads not covered by Highways Agency

The name of the responsible person/authority to which the Duty of Care has been passed must be forwarded to Fire Control by the Incident Commander for inclusion in the incident log.

It is inevitable that some delays may be encountered in the attendance of the responsible authority for removal of hazardous substances, e.g cylinders, containers etc.  On such occasions, an adequate attendance of fire service equipment and personnel must remain in attendance until the duty of care is transferred to the responsible authority.

Advice and guidance must be sought from a specialist hazardous substances officer where any doubts exist.

Fire service appliances must not under any circumstances be used to transport any type of hazardous substance, e.g. LPG cylinders, chemical containers, etc., for disposal on return to station.

Fire Service PPE and other equipment that is contaminated at an incident must be suitably decontaminated and appropriately sealed at the incident site, under the guidance of a specialist Hazardous Substances Officer, before being transported back to the relevant fire station(s).



The following technical information should be brought to the attention of operational personnel with a view to scheduled further training regarding this subject.

Home Office GRA 5.3 – Chemical Incidents

2000 Emergency Response Guide book

Manual of Firemanship Book 12

WMFS Hazardous Substances Portfolio (Sections to be promulgated)

Existing WMFS Operations and Training Note 22 – Section 3 Decontamination.