The Organization for the Prohibition of Chemical Weapons (OPCW) defines a chemical warfare agent (CWA) as “any toxic chemical that can cause death, injury, temporary incapacitation or sensory irritation through its chemical action.”
The Chemical Weapons Convention (CWC) provides a broader definition to include toxic chemicals, their precursors, munitions and devices, and “any equipment that has been specifically designed for use in connection with such weapons.”
The Convention also applies to any chemical that might normally be used for peaceful or commercial purposes but that has been used as, or applied to, the creation of chemical weapons.
Chemicals may also be classed as CWAs if they are produced or stockpiled in quantities that exceed the prohibitions of the CWC.
CWA Treaties and Regulations
Recognition of the global threat of CWAs dates back many hundreds of years.
The first formal international agreement to control the use of chemical weapons was signed in Strasbourg in 1675 when France and Germany agreed to ban the use of poisoned bullets.
In 1874, the Brussels International Declaration on the Law and Customs of War prohibited the use of poison or poisoned weapons and the use of any arms, missiles or projectiles deemed to cause unnecessary suffering.
In 1899, a third agreement, ratified at an international peace conference held in the Hague, banned the use of projectiles filled with poison gas.
The 1993 Chemical Weapons Convention aims to eliminate an entire category of weapons of mass destruction (WMDs) by banning the development, production and stockpiling of CWAs.
The Convention rules that toxic chemicals are only to be developed and produced for purposes unrelated to chemical weapons. All States Parties agree to chemically disarm by destroying any stockpiles of chemical weapons and the facilities that produce them.
A unique feature of the Convention is the ability for any State Party to challenge the compliance of another through the request of a ‘challenge inspection.
What are the physical properties of CWAs
CWAs are stored as liquids but can be deployed as liquids, solids or gases.
They are highly toxic, often fast acting, mostly imperceptible to senses, persistent and non-persistent
Exposure to a CWA is normally one or more of three main routes - skin, eyes and/or respiratory tract, but can also be adsorbed via mucous membranes..
Liquids tend to be absorbed via skin through direct exposure to a contaminated surface while vapours pose greater risk for absorption via inhalation.
Vapours that are used outside can very easily be blown off course and away from their intended target. Similarly the weather can be used to maximise their effect.
The effects of CWAs are also markedly enhanced when they’re used in a confined space.
The effects of exposure to a CWA can be immediate or delayed depending upon:
Why are CWAs popular as a weapon?
What is the risk of exposure to CWAs?
Exposure to CWAs can be be accidental, in the process of casualty management, an industrial incident, military stockpiling or the discovery of leaking shells in old battlefields. Exposure has also occurred during ordinance disposal / demining when CWA markings have become unreadable or have been misinterpreted.
In recent time CWAs have also been used as a means of actual or attempted assassination, terrorist attack or act of war.
Categories of CWAs
CWAs can be broken down into several categories according to:
Nerve agents are part of a group of highly toxic and environmentally persistent organo-phosphorous (OP) compounds that affect the transmission of nerve impulses in the nervous system.
They are stable, easily dispersed, highly toxic and can have rapid effects via either skin absorption or respiration.
The first known nerve agent is Tabun, which was developed by German scientist Gerhard Schrader as part of his research into the creation of insecticides.
The only known wartime use of nerve agents is reported to have been during the Iran-Iraq war, 1980 - 1988.
Examples include: Sarin, Tabun, GF, VX, Soman, cyclosarin, Novichok
Blistering agents are primarily dispersed as liquids or vapours that can persist for days, if not longer and cause a delayed effect. Deaths account for only a small percentage of casualties.
Examples include: sulfur mustard (H,HD), nitrogen mustard (HN), lewisite (L) and phosgene oxime (CX)
Choking agents cause severe irritation or swelling of the respiratory tract (the lining of the nose, throat and lungs.)
In extreme cases the lungs become filled with fluid, causing a lack of oxygen which can lead to death. Choking agents were the first CW agents to be used extensively during WW1.
Examples include: chlorine (CL), phosgene (CG), diphosgene (DP)
Blood agents form part of a cyanide group of chemicals. They affect the body by preventing the utilization of oxygen within body tissue.
Blood agents typically enter the body via inhalation and cause the body to suffocate.
One such agent, hydrogen cyanide, was first discovered in 1872 by Swedish scientist Carl Wilhelm Scheele and was used as an industrial chemical before being employed by the French during the Battle of the Somme in 1916.
Examples include: hydrogen cyanide (AC), cyanogen chloride (CK), and arsine (SA).
Riot control agents
Riot control agents (RCAs) - also referred to as harassment agents - are liquid or solid chemical compounds that cause a temporary lack of function by irritating the eyes, mouth, throat lungs or skin.
RCAs fall into one of three categories:
Examples include: pepper spray (OC), CS gas (tear gas), adamsite, diphenylchlorarsine, dipenylcyanoarsine
Exposure is typically via ingestion but can also be through transdermal absorption, inhalation or injection.
Examples include: fentanyl, etorphine.
Psychomimetic agents are incapacitating agents that cause changes in perception, thought or mood.
When administered in low doses they can cause loss of feeling, paralysis or hallucinations.
Examples include: BZ, Agent 15.
Records of chemical warfare date as far back as 600BC when the Athenian military contaminated the water supply of the besieged city of Kirrha with highly toxic hellebore roots.
The mass production of CW agents became more prevalent in the 19th century following the development of industrial chemistry.
Within modern warfare, the first large-scale use of CWAs occurred during the First World War when the German military released 168 tons of chlorine gas in Ypres, Belgium, in April 1915, killing 5000 Allied troops.
Phosgene gas (a colourless irritant six times more deadly than chlorine gas) was also used by the Allies during the First World War. Phosgene is recorded to have been responsible for 85% of the conflict’s chemical weapons fatalities.
Mustard gas, a potent blistering agent, is reported to have caused the highest numbers of injuries during WW1, with the total number of casualties estimated at approx 120,000.
The Geneva Protocol is adopted by the League of Nations. It bans the use of chemical or biological agents in war but doesn’t prohibit their production, development or stockpiling
Mussolini drops mustard gas bombs on Ethiopia in the Italy-Ethiopia conflict
German chemist Gerhard Schrader completes synthesis and purification of the potent nerve poison Tabun
Poisonous gases are used by the German and Japanese armies in World War 2
British serviceman Ronald Maddison dies after being voluntarily exposed to the Sarin toxin at the UK’s Porton Down military facility
The Biological Weapons Convention bans the development, production and possession of biological weapons, but provides no means to ensure compliance
Iraq uses chemical weapons including Tabun against Iran and Iraq’s Kurdish minority in the attack on Halabja
The Chemical Weapons Convention is signed, in which all States Parties agree to chemically disarm and destroy any stockpiles of chemical weapons
1994 - 1995
Two Sarin attacks in Japan leave 19 dead and 5280 injured, the worst chemical event in modern Japanese history
The CWC disarmament agreement bans the development, production, stockpiling and use of chemical weapons
The use of a fentanyl derivative in Moscow against terrorists holding hostages results in 120 casualties due to asphyxiation
The Syrian military uses sarin gas against civilians during the Syrian civil war
A suspected sarin and chlorine gas attack in Douma is reported to have killed up to 150 civilians and injured hundreds more
Historically chemical warfare agent (CWA) training was confined to specialist training areas, generally on a military base.
Training typically involved the use of simulants which were dispersed manually using something like a plant sprayer or by pyrotechnic means.
Nowadays the primary reason for CWA training is for terrorist related threats. This in itself presents different training challenges. For example:
Live agent training (LAT) is a special opportunity for trainees to understand the characteristics of a live threat in a controlled manner. But what is important is that they get the very best out of that opportunity without wasting time struggling with learning how to use their detectors.
Historically CWA detection has tended to consist primarily of determining if Blister agent (H) or Nerve agent (G) was present.
Some detectors also had the capability of detecting a few additional agents. But, by and large, the relatively limited detection capability was dictated by the perceived threat at that time, which of course drove the market for detectors.
In many instances, users would only have one type of detector available, usually IMS (ion mobility spectrometry) or Flame Photometry.
The ability to specifically identify substance threats was generally restricted to “man portable“ or vehicle-mounted gas chromatograph / mass spectrometers (GC/MS).
The need to reduce uncertainty, as to whether a false positive or actual threat exists at the initial point of detection, has resulted in many agencies employing more than one detector technology - quite often a mix of IMS and Flame Photometry - each incorporated within different instruments.
While this approach will dramatically reduce the probability of a false positive being interpreted as a threat, GC/MS are still used by many agencies to specifically confirm the identification of the substance present.
IMS technology and the associated processing software has advanced to permit agent identification, however the ability to do so is achieved by limiting the detection capability to a relatively narrow range of substances.
Some manufacturers also offer detectors which are in fact comprised of hybrid technologies to both reduce false positives and enhance substance detection capability.
These advances in both detection requirement and detection technology require that the training experience accurately reflects the capability of the detection instruments to ensure your students understand why respective detection technology has been employed.
This can be achieved by employing a simulation detection technology that is configured to represent the specific capabilities and characteristics of the detection technology incorporated within the real instrument.
New generations of intelligent, computer-based simulation tools offer a real and workable alternative to conventional CWA training methods.
Electronic simulators accurately replicate how real devices react when confronted by a range of chemical agents, taking into account the volatility of the agents, the prevailing meteorological conditions and the tactics and techniques used to detect differing agents.
The key difference is that there is no use of chemicals of any kind. Instead, electronic simulation agents are used.
The main driver for using simulators is the ability to be able to detect and monitor an invisible or near-invisible hazard as it moves through the air or contaminates equipment, infrastructure or terrain.
The greatest challenge is ensuring that the hazard environment is accurately portrayed, so that no false lessons are learned.
To mitigate this problem, simulation manufacturers include a built-in after action review (AAR) capability which allows interrogation of the simulator after use to determine if it was operated correctly.
Using an electronic means to simulate chemical vapours enables instructors to create useful exercises that test their students’ abilities in the following core skills:
Substantially more can also be obtained from an exercise than a simple “reading on a detector.”
The simulation source can be readily hidden from view and can be configured to represent a number of different substances to enable both CW agent and toxic industrial chemical (TIC) scenarios to be produced within the same exercise.
The emission level can be varied by the instructor such that, at maximum strength, a simulator will detect at typically 30 metres (95 feet) from the simulation source in free space.
The simulation source can be easily hidden, and multiple devices can be deployed to represent different substances within the same scenario.
Instructors save valuable time as it takes only a couple of minutes to set the source to the desired substance and emission level before placing it.
The instructor retains complete control over the entire exercise scenario. They can set up an exercise early in the day, test the expected readings on the simulators, and guarantee that when it comes to exercise time everything will be as they left it, leaving them to concentrate on student evaluation.
When the exercise is complete it takes a matter of minutes to collect the sources and remediate the training facility.
Simulator detectors offer a variety of advantages for realistic CWA training:
There is no requirement for the administration associated with radioactive sources
Many IMS detectors use an ionizing radiation source which is subject to regulatory controls (such as movement and storage certification and costs), regular wipe testing with associated time, costs and administration.
No expensive consumables
Most IMS detectors have sieve packs which are consumable items that can add significantly to the cost of training over time.
No need for gas
Whilst flame photometry detectors do not suffer from either (1) or (2) above, the requirement for hydrogen gas is a relatively expensive ongoing training cost.
No wear and tear of real detectors
Students break detectors used during training. This is inevitable; however the cost of repair is often not trivial. Then there is the time it takes to get the detector repaired.
They safeguard against student misuse
From time to time, students will mishandle their detectors.
When this happens, the detector then typically saturates and goes into “wait” mode, meaning that valuable teaching time is then taken up rectifying the problem.
A well designed electronic simulator will tolerate student misuse and, when it occurs, it will simply monitor the actions, generate a report and reset back to its original state.
No need for regular maintenance
Detectors can require ongoing preventative maintenance, and in some cases regular calibration, in order to work correctly.
A well designed simulator, on the other hand, requires no preventative maintenance, or regular calibration and uses no consumables other than disposable batteries.
In cases when a real detector has user-replaceable consumables - such as a hydrogen cylinder (Proengin AP2C, AP4C) or sieve packs (Smiths Detection LCD series detector including JCAD, NEXUS and GID-M, Bruker RAID) - the simulator is able to replicate these consumables so the student can practice the replacement procedure.
They avoid damage from wrong consumable replacement
Incorrect replacement of consumables (or turning the detector on without a sieve pack fitted) can result in a very expensive repair or in some cases a ruined detector.
Clever use of technology means you can still simulate the effects of contamination without the need to use a substance. Your decontaminant can be as simple as soapy water.
The instructor can then determine if the instrument response to the simulation source should reduce partially (to demonstrate that decontamination drills were poorly executed) or reduce fully (to simulate a job well done).
There are cost advantages
But aren’t simulators more expensive to buy than real detectors?
In general, the answer to this question is yes.
But this is not always the case - and certainly not when whole-of-life costs are considered.
The true cost of using a real detector is a combination of many factors (regulatory compliance, land remediation, replacement of consumables, maintenance etc).
And when those costs are spread over the typical lifetime of a detector (say 10 years), they can be dramatically higher than the initial capital cost of a simulator divided over the same period of time.
When training with simulators, the only ongoing cost (aside from batteries) is repair. Although the administration related to repair of simulator detectors is easier and less costly as there is no chemical source and no requirement for cleanliness certification.
The technology employed within a simulator is also purely electronic, rather than scientific instrumentation which removes the need for specialist repair facilities, such as clean rooms.
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In this section we explore twelve types of electronic simulator detector that can be used in a wide range of CWA exercises to create realistic training experiences.
The devices can be used anywhere, including within public buildings and most scenarios can be set up in as little as 10 minutes.
A high-fidelity detector simulator that replicates the Smiths Detection LCD3.2e and is compatible with PlumeSIM.
The LCD3.2e-SIM simulates:
A dedicated simulation instrument for training in the correct use of the Bruker RAID M / RAID M100 in virtually any scenario and environment.
Enables simulation of:
A high fidelity simulator for the Smiths Detection M4 JCAD.
A high fidelity simulator for the Smiths Detection LCD3.3 and LCD3.3FR.
Enables simulation of:
A chemical hazard simulation training system that allows safe and comprehensive training in the correct use of the Smiths Detection GID-3, without external simulants or other consumables.
Key features of the GID-3 SIM:
ACADASIM enables training in the use of Smiths Detection’s M22 ACADA detector and remote alarm.
Multiple simulators can be remotely controlled in real time using a single PDA, allowing an instructor to monitor that students are correctly following a detector’s set-up procedure, and that they are able to perform simple fault diagnosis and remedial action in response to simulated faults.
Key features of the ACADASIM:
The ChemPro 100/100i system enables the training of first responders and CBRN troops in the use of the ChemPro100 and the correct action under a chemical attack.
Simulated alarms can be created to appear on the display of the ChemPro 100/100i Simulators and user actions monitored by means of an optional powerful instructor remote.
Simulated alarms can also be initiated by a point source or long range vapour simulator.
Enables simulation of:
The CAMSIM CAM simulator for the Smiths Detection Chemical Agent Monitor (CAM) detector.
Different versions representing all versions of CAM are available that can simulate:
*As applicable to the version of CAM simulated including ECAM and ICAM.
A simulation training system for the Proengin AP4C.
Enables simulation of:
A simulation training system for the Proengin AP2C.
Enables simulation of:
A training simulator that looks and functions just like the Proengin S4PE surface sampler and confidence tester when used with AP2C and AP4C detectors.
Key features of the S4PE-SIM:
Enables simulation of:
A high fidelity simulator for the Smiths Detection M4A1 JCAD.
Enables simulation of:
PlumeSIM enables training of multiple personnel over areas up to 15 square kilometers.
It allows instructors to select the parameters for the activation of simulation instruments - including the type of threat, release/delivery of single and multiple sources and a full range of environmental conditions.
Instructors can also record the actions of trainees from a single location.
Features of PlumeSIM:
PlumeSIM-SMART enables an instructor to select the threat substance, release type, timing and duration of single or multiple virtual radiation or chemical plumes.
It also allows for the configuration of meteorological conditions and for modifications in wind direction and velocity to affect plume dispersion throughout the exercise.
Powerful App based simulation instruments respond in real time according to the evolving simulated threat environment and characteristics / configuration of the simulated detector.
Students manoeuvre throughout the exercise area either by means of a virtual gamepad or GPS tracked physical movement.
Instructors can rapidly deploy scenarios involving toxic substance releases, industrial / petrochemical facilities, nuclear reactors and radiological sources / devices, which can be saved as libraries for future use and shared with other users.
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The Proengin AP2C detector uses Flame Photometry and primarily detects the presence of sulphur and phosphorus.
A lookalike simulation detector can indicate a reading as a result of a simulation stimulus that represents a substance containing either sulphur of phosphorus.
If you also implement a training simulator that represents an IMS based detector such as the Smiths Detection CAM or LCD / JCAD series detector, you can configure this to provide an indication in either the G or H mode whenever an appropriate simulation stimulus is received.
Similarly you can configure a simulation source to represent a TIC or Blood / Choking agent.
An electronic simulation vapour generator can be set to represent a specific substance, for example the nerve agent Sarin.
The AP2C simulator provides an indication in the P channel which would indicate that a nerve agent might be present.
A CAM / LCD (M4-JCAD in the USA) simulator would provide an indication in the G channel, which would also indicate that a nerve agent may be present.
The same principle can be applied to the Blister agent detection channels, with the simulation source representing a blister agent and the appropriate reading being obtained on the AP2C simulator S channel and CAM / LCD simulator H channel.
There is of course a danger here as you don’t want a student to fall into the trap of assuming that if a CAM / LCD obtains a reading in H mode, but an AP2C does not obtain a reading in the S channel, then the CAM / LCD is surely responding to a false positive.
By making use of programmable vapour simulators you can easily set out a scenario in which, in one area, a student obtains a reading on just the H mode of the CAM / LCD simulator and nothing on the AP2C simulator whilst at a different location they receive readings on both the G mode on the CAM / LCD simulator and P channel on the AP2C simulator.
You would not be surprised if your student interpreted the scenario as having G agent with a false positive H in a separate location, even though your scenario incorporated both Nitrogen Mustard and Sarin.
(It’s important to note of course that an AP4C simulator would provide an indication in the appropriate channel).
The introduction of a simulator representing a detector capable of detecting or identifying specific substances would reveal all and bring home a useful lesson.
Using a RAID-M100 or LCD 3.3 (M4A1 JCAD) simulator in these scenarios would produce useful agent identification details.
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Opportunities to develop CWA scenarios are limited only by your imagination.
But to get you started, here are twelve examples of scenarios that can be applied in any chemical / HAZMAT exercise where simulators are used.
One or more detection simulators can also be employed as is appropriate.
Scenario 1 - Suspect package
The simulation source can be hidden in cartons, luggage cases, holdalls, rucksacks or an item that might be used to smuggle something.
You can also set the source to provide a reading only when the student gets very close to the item in question.
The suspect package could be placed among other packages; in an office or room; within a vehicle; within a means of public transport such as a train, aircraft or bus.
Scenario 2 - Suspect vehicle 1
The source can be placed within the luggage storage compartment of a vehicle.
Vehicles of different quality have different quality of seals, but by experimentation you can determine the best setting and location for the source in order to obtain the readings you want your student to experience when they check the suspect vehicle.
Set the simulation source to a high level, hiding it perhaps under a wheel arch.
The student will receive readings from a sufficient enough distance (representing cross contamination) that, if other vehicles are parked close by, it will not be obvious which vehicle is involved.
Set the simulation source to a low level and you can really challenge the operator’s search capability and methodology.
Scenario 3 - Suspect vehicle 2
Place the simulation source either within a package on the rear seat of the vehicle or underneath the seat of the vehicle.
Leave the side window of the vehicle slightly open.
Set the simulation source such that readings are obtained just at the window opening. This is especially realistic for CW / suspect device search training.
Scenario 4 - Contaminated vehicle
Place a simulation source under the wheel arch of a vehicle. Set the instructor controller to partial decontamination and check a low reading (representing residual CW agent) can be obtained.
Set the instructor controller to a high response level. The student will now need to search for contamination.
When decontamination begins, the instructor observes the process. If the instructor is not happy, the partial decontamination control is set. When the student returns a residual reading will be obtained, provided the student searches thoroughly enough. If they do not, the instructor can demonstrate where the residue can be found.
Scenario 5 - Survey / Reconnaissance
Place simulation sources as required in open ground to be checked. A student will obtain readings as the area is approached.
To simulate non persistent agent use instructor control to reduce reading after required period of time.
Scenario 6 - Search false positive
Set a simulation source to represent a false positive.
Place it in a location that would most likely cause a false positive on a real detector, such as where fuel is stored or where cleaning chemicals are located in a building.
Scenario 7 - Personal decontamination
Place an electromagnetic simulation source within a person’s clothing. Set the instructor controller to ‘partial decontamination’ and check a low reading (representing residual CW agent) can be obtained.
Set the instructor controller to a high response level. The student will now need to search for contamination.
When decontamination commences, the instructor observes the process.
If the instructor isn’t satisfied then they can set the partial decontamination control. Then, when the student returns, a residual reading will be obtained, provided they’ve searched thoroughly enough. If not, the instructor can demonstrate where residue can be located.
Scenario 8 - Simulated CW weapon
Hide the simulation source within a weapon housing. The student will obtain a reading as they approach.
If the weapon is “wrapped” to prevent vapour emission, the simulation source emission will be reduced and the detector reading will reduce. If the weapon is wrapped adequately the emission will reduce completely.
Plaster of Paris is an especially effective wrapping tool, as it eliminates vapour emission while the plaster is wet and, as it dries out a reduced reading will be obtained. Additional plaster can then be added - resulting in a zero reading.
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Scenario 9 - Simulated Improvised Explosive Device (IED)
Place the simulation source in the required location and set the instructor control to prevent the simulator from responding to the simulation source.
At the time you wish to simulate the release of substance, select ‘full response’ for rapid release or ‘partial response’ (followed later by ‘full response’) for slower release.
Scenario 10 - Room breach training
Set the simulation source so that the CW / HAZMAT reading is obtained when the door of the room is carefully checked (at the edges where the door meets the doorframe.)
When the door is breached, the reading will rise without the students having to enter the room.
Scenario 11 - Building search training (pre entry)
Install a simulation source within the building such that an emission is just detectable through an open window when the detector sensor is placed through that window.
This scenario is an ideal way to teach external assessment of a building prior to entry.
Scenario 12 - Search training
Use a standard locker room with a bank of multiple locker cupboards. Place a simulation source within one of the lockers such that a reading is only obtained when the student is very close.
Video record the search and play it back to your class to see how methodical the search technique was. For example the student may have started methodically but later relaxed or monitored in a random fashion, which meant they missed the simulation source.
Once you develop a catalogue of your own scenario ideas, you will be amazed at how quickly you can set up your exercises.
Not only that, but you can be certain the students will experience exactly what you want them to as they carry out the exercise you have planned to ensure they have understood the classroom lectures.