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The threatened use of chemical, biological, radiological, and nuclear (CBRN) materials has not significantly abated in recent years.

One of the reasons such weapons are considered taboo in international law is that many CBRN weapons cause short- or long-term contamination, which must often be addressed through time-consuming and resource-intensive contamination efforts. Last year (ESD 2018-5) this magazine discussed many of the issues particular to military decontamination.

Military Decontamination

Military requirements for removal and/or neutralisation of CBRN hazards broadly declined in Europe after the end of the cold war, but have never gone away entirely. There is a continued existence of CBRN threats, despite the general overall success of arms control treaties. Various UN, NATO, and EU operations keep European militaries, ground forces in particular, in areas where CBRN threats may occur. Gradually, new life has been breathed into the CBRN decontamination arena in the European defence industrial base.
A relatively narrow group of companies dominate the European landscape in military decontamination. Kärcher Futuretech (Germany), Cristanini (Italy), and OWR (Germany) all are significant players in military decontamination. All three provide a full spectrum of decontamination products, systems, and technologies. That two of the three are German firms is a strong reflection of the Bundeswehr having decades of experience taking the CBRN threat seriously, and both had a strong history of supplying German military requirements.

OWR, based in Elztal-Rittersbach in southern Germany, provides a variety of systems for military (and civilian) decontamination roles. A pillar of their product line is the truck-based MPD 100 heavy decontamination system, which can be configured for any major decontamination task. It can support personnel decontamination up to 120 persons per hour, or it can support vehicle and heavy equipment decontamination. An improved version, the MPD 100i can do up to 240 persons an hour. Decontamination systems are often used to apply generic products, such as bleach or soapy water. But manufacturers put great effort into development of specialty solutions for CBRN decontamination. OWR’s own proprietary decontamination solution is GD-6, which is a replacement and improvement on their older GD-5 product. (GD-5 apparently is still on the market in some areas.) GD-6 is notable in that it is meant to be used without water, whereas some rival products are concentrates that are meant to be diluted in water. Since it is useable without water, it is less damaging to sensitive items of equipment. GD-6 was, notably, adopted by the Canadian military as a standard decontaminant and it is now in service with a number of NATO militaries. As a solution for decontaminating chemical and biological threats, GD-6 has proven highly effective in a number of trials and tests. VOP-026, the noted Czech CBRN laboratory has produced a report on use of GD-6 with actual warfare agents and the results, widely available online, are impressive.

Civil versus Military Requirements

The main uses of CBRN weapons in recent years have been in civilian or partly civilian environments. These have included brazen air and rocket attacks against civilians in Syria, an assassination in an airport in Malaysia, and the use of “Novichok” agents in the UK. Also, historically, the anthrax terrorism in 2001 in the USA is of significance. All of these show that CBRN terrorism is not just a military problem, but one for civil authorities as well.

As with every other aspect of defence and security, decontamination is not an area where every military product and technology can be converted to civilian use with a coat of green paint, although some vendors have attempted this tactic in the past. Some of the difference is due to the great variety of things that might need decontamination in an urban setting and the need to reduce property damage from use of harsh decontaminating agents. Something useful for decontaminating nerve agent on the side of a tank may be too dangerous to use in residential settings.

Many products designed for personnel decontamination are meant to go onto human skin. However, such products are effectively regulated as medical products if they are going to be used in a civilian environment. The regulatory hurdles are non-trivial and take much time and money for a manufacturer to surmount. For decades there have been products in military service which can be used by soldiers which were simply illegal for use on a civilian terrorism victim. For example, the US Army had a powder-based sorbent skin decontamination kit called the M291, which was legal for military use but of questionable regulatory status on civilians. However, some positive developments have begun to occur. Emergent BioSolutions (USA) received US Food and Drug Administration approval for their Reactive Skin Decontamination Lotion for civil use.

New Horizons

In the 1980s and 1990s, there were years when the only tangible improvements in CBRN decontamination were, literally, improved plumbing and better water tanks. Much of this had to do with simple economics. CBRN decontamination has long been a field where cheap generic materials still have some dominance. Specialty products cost far more than generic decontaminants like bleach, soap, water, or the mineral Fuller’s Earth. The fact that specialty products were orders of magnitude more expensive than soap and water, but often were only twenty percent more effective at dealing with some contaminants, has been an intractable philosophical problem in CBRN decontamination for decades. The 21st century, so far, has seen number of new products. All of the major manufacturers produce decontamination solutions (e.g. Kärcher’s GDS 2000, Cristanini’s BX-24, OWR’s GD-6, and the US “Sandia Foam” now made under licence) that are indeed superior to soap and water in many ways. The struggle now, however, is one of economy. Water, bleach, and soap are not any less effective than they were before, and are far cheaper than specialty powders and liquids. Actual CBRN warfare or widespread terrorism will consume a lot of decontamination products, and none of the specialty products are known for being cheap. The next challenge will be to make the same level of effectiveness more affordable to allow acquisition of large stockpiles.

Fumigation and Large Volume Decontamination

One new horizon is improved fumigation. Fumigation is an old technique for dealing with vermin, such as rodents and insects. As such, it can easily be considered a form of biological decontamination. Fumigating agents, such as ethylene oxide have a long history of such uses in industrial settings. In 2001 and 2002, the gas chlorine dioxide saw much use in the decontamination of contaminated offices and mail-handling facilities. However, older fumigating agents pose serious issues. Chlorine dioxide can be dangerous to property while ethylene oxide is a fire and explosion hazard. Neither are particularly good for sensitive items like electronics. Damage to property is a valid concern in building decontamination after a terrorist event. In at least one instance after the anthrax terrorism in the USA in 2001, decontamination forced abandonment as the costs would have exceeded the value of the building.

STERIS (USA), known more for its products in the mainstream medical care market, has entered the CBRN marketplace with various systems that use hydrogen peroxide as a fumigating agent. This has shown great promise as vaporised hydrogen peroxide is a reasonably effective chemical and biological decontaminant. Of great note, this method is less destructive of materials, and can decontaminate sensitive items like aircraft electronics or medical equipment. The virtue of STERIS’ approach is that it is scalable. Systems could be made as small as a cabinet for small items, and as large as a hangar to decontaminate a tank or a fighter jet. STERIS is not the only player in this segment. Bioquell (UK) pursues hydrogen peroxide-based decontamination as well. It should be noted that this particular market segment is more driven by hospital sterilisation requirements and that the defence market is a small subset of the overall business of these companies. This is not a detriment to the technical quality.

Vehicle decontamination with foam solutions from DEW (Photo: DEW)

Cristanini (Italy) has similarly pursued decontamination by fumigation. However, they have not pursued hydrogen peroxide. They have fielded a product called LVD-X. This system uses a fine mist of hydroxyl radicals. One or more of their spray systems can be used to fog an enclosed space, such as a room or a compartment on an aircraft. The properties of the hydroxyl radicals are such that sensitive electronics are unharmed by this fumigation process. The product offering is less extensive than STERIS, but is eminently affordable and is scalable simply by using multiple units. Testing on actual chemical warfare agents occurred at the Czech laboratory VOP-026 and this technology clearly does work to reduce contamination on a variety of surfaces.

Enzymes and Catalysts

Chemical warfare agents are generally degraded by contact with water in a chemical process known as hydrolysis. If time and water supply were no impediment, water is not a bad decontaminant in itself. However, various tricks can be used to speed up hydrolysis. Some of the older techniques involve raising or lowering the pH of the water with acids or bases. However, this can be quite physically destructive to whatever surface has been contaminated. One way to approach the problem is to find chemical substances that work as “catalysts” which improve the efficiency and effectiveness of hydrolysis or other mechanisms by which chemical warfare agents can be degraded. Many, but by no means all, of these catalysts are enzymes. “Enzymatic decontamination” has been an area of legitimate inquiry since at least the early 1990s.

One commercially available product in this category is DEFENZ, produced by Genencor (USA), a branch of DuPont. The DEFENZ VX-G product works against nerve agents and DEFENZ B-HD is designed to work against Mustard agent. Both can be dissolved into water or foam. The US EPA evaluated these products in 2013 and have published the test results online. Based on reading the 2013 report, it can be fairly stated that these products are good, but still show room for improvement.

There are legitimate criticisms to be made in enzymatic and catalytic decontamination. First, these substances are never cheap. Generally, these substances are highly specific to specific threats. For example, there are specific enzymes that work only on the nerve agent Sarin. If you have some other nerve agent, they won’t work. Some substances in this family are somewhat more broad-spectrum than others. But if you do not know what exact substance you are dealing with, you might need to throw an entire cocktail of chemicals at the contamination, and end up wasting the enzymes that are not applicable to the problem at hand. In the heat of battle, very costly goods could end up being washed down the drain. Likewise, a decontamination effort that used the wrong cocktail would only be as good as the water in which the expensive enzymes were dissolved.

Detection Helps

Decontamination, both in military and civil settings, works best when it is intelligently combined with detection instruments. A “decontaminate everything everywhere” strategy is illogical and not logistically sustainable. Military commanders and civil authorities will be burdened with decisions. Someone needs to decide what actual vehicles, items of equipment, personnel, and areas need to be decontaminated. Detection instrumentation, which has been discussed several times in this publication in past issues, is particularly relevant to this decision-making process.

The area of CBRN detection is one that has historically been full of both inadequacies and many changes to products and technologies. It changes more quickly than the decontamination market segment. However, one of the areas of the detection segment that is most mature is monitoring of surface contamination for chemical or radiological hazards. Surveying surfaces (such as on an armoured vehicle) for contamination, both prior to decontamination and as a quality control measure after decontamination, is one of the older missions for detection instruments. Many of the current detection instruments stem from technologies originally crafted for contamination monitoring.

A DSVP 10 C Rapid Response System in action (Photo: Kärcher Futuretech)

One of these technologies is flame ionisation detection (FID). An FID device takes a sample and ionises it using a hydrogen flame. As it turns out, this technique is highly useful for detection of persistent chemical warfare agents on surfaces. Decades of testing with chemical warfare agents shows that FID detection works very well on phosphorus compounds, which includes nerve agents, and sulphur compounds, which includes so-called “Mustard Gas.” The only real player in the chemical warfare FID market is Proengin (France). For decades, their AP2C was the industry standard FID device, and it is still marketed by Proengin. It has been supplanted by the AP4C, which is a superior instrument to the AP2C with a broader library of chemical agents that it can detect. Some will make criticisms about these instruments in other applications beyond their original design scope. However, in the detection of specific chemical warfare agents on surfaces, such as required by decontamination operations, these instruments give excellent performance.
By far the oldest surface contamination detection technique is not actually an area of instrumentation, as it predates handheld electronic detection instruments. One can use colorimetric detection paper to detect the major categories of chemical warfare agents on surfaces. Absorbent strips of paper are treated with specific reagents than change colour when exposed to various categories of chemical warfare agents. Such techniques go back many decades, but are firmly established as highly economic yet low-tech solutions to the problem of locating contamination. This is an area where the specialty Czech firm Oritest has a well-defined market position. Their CALID-3 chemical warfare detection paper sets the standard in this niche.

How Clean is Clean Enough?

A perennial problem in decontamination is one of knowing when to stop. How clean is clean enough? Ideally, the standard would be zero presence of hazard. However desirable this might notional standard might be, it is utopian and is completely unrealistic for a variety of reasons. Every type of detection and measurement instrument has a threshold of detection below which it cannot accurately function. This means that, in any particular scenario, there will be levels of contamination left after decontamination that cannot be measured. A standard of zero contaminant is therefore technically unrealistic.

Decontamination works best when it is intelligently supported by detection instruments. Shown here is an AP2C-V chemical agent detector from Proengin mounted on a NBC reconnaissance vehicle of the Japan Ground Self-Defence Force. (Photo: Wikimedia Commons)

Since the theoretical level of zero contamination cannot be adequately measured, there needs to be serious discussions of what level of hazard is, therefore, acceptable. This sort of discussion is often difficult, because it involves substances that are inherently dangerous. A rational risk assessment involving military troops and military equipment can easily occur and lead to a reasonable standard for use in military operations. However, such a standard may not be acceptable in civilian settings. Public health considerations and practical politics will likely drive a lower level of acceptable contamination. Further, new threats such as so-called “Novichok” agents have poorly understood human toxicology and there is not the body of knowledge available to allow for a full assessment of what small levels of Novichok contamination might be permissible to remain after decontamination. The problem of “how clean is clean enough” is going to be a philosophical problem in CBRN decontamination for some time to come.


CBRN decontamination has long been considered one of the more difficult subsegments of the CBRN industry in terms of economics and profitability. When one’s competing technology is essentially free (water), it can be hard to make a good business case that a particular product or system is worthy of investment. However, new and interesting technologies and products continue to emerge in this segment.

Dan Kaszeta is Managing Director at Strongpoint Security Ltd. and a regular contributor to ESD.