Analysis of Some Accidents Involving Manufacture,

Transport and Storage of Base Emulsion

by Dr. Peter Moreton

SAFEX Topical Papers Series

Paper No. 06/2009

SAFEX International

SAFEX Topical Paper Series

The papers in SAFEX’s Topical Paper Series acknowledges the work done by the SAFEX

community in promoting better health, safety and

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its mission of exchanging relevant HS&E information among its members, SAFEX continually encourages

members of its community to submit such papers for

consideration as a Topical Paper.

An analysis of some accidents involving manufacture, transport and storage of base

emulsion

by

Dr Peter Allan Moreton, BA, MSc, PhD, MRSC MBTB Ltd,

SAFEX Topical Papers Series Paper no 06/2009 Published: April, 2010

A version of this paper appeared in the December 2009 edition of Explosives

Engineering, published by the Institute of Explosives Engineers

The information in this publication is based on the author’s experience and general industry practices at the time of publication. The views expressed are those of the author and do not necessarily represent the official position of SAFEX International. The publication should be read in conjunction with regulatory and statutory requirements as applicable. All recommendations contained in this publication are made without guarantee. The author and SAFEX International cannot accept any liability for consequences arising (whether directly or indirectly) from the use of such advice.

About the author Dr Peter Moreton is a chemist by training, having completed a PhD in analytical/environmental chemistry in 1984. His interest in explosives began while he was doing post-doctoral research at the Royal Military College of Science. At this time he became involved in the application of risk assessment techniques to ensure safe storage of explosives, particularly in situations where the standard quantity-distance prescriptions could not be met. He was a senior consultant with the UK Atomic Energy Authority from 1987 to 1999, developing and applying risk assessment techniques to a variety of hazardous activities, including the storage and transportation of explosives and ammunition. He was instrumental in developing the Explosives Incidents Database Advisory Service (EIDAS) in the early 1990s. This service was originally developed on behalf of the UK Health and Safety Executive (HSE) and the UK Ministry of Defence, and he has continued to maintain EIDAS on behalf of these organizations to the present day. Since 2000, Dr Moreton has worked as a freelance safety consultant, trading under the name of MBTB Ltd. His clients include the HSE, MoD, the Confederation of British Industry, as well as a number of explosives manufacturing companies based in the UK.

Contact details:

28 Hazelborough Close, Warrington, Cheshire, WA3 6UL ENGLAND Tel: 0044 1925 831175 Fax: 0044 1925 831175 email: petermoreton@msn.com

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CONTENTS

1. Introduction ................................................................ 2

2. Accidents during manufacture of base emulsion ..... 5

Kairuan, China ......................................................... 5

Yongan, China ......................................................... 6

Dongfong, China ...................................................... 7

Abest, Russia ........................................................... 7

Chongqing, China..................................................... 8

3. Accidents during storage of base emulsion ............. 9

Porgera, Papua New Guinea .................................... 9

4. Accidents during transport of base emulsion..........10

Usmanka, Russia ....................................................11

5. Accidents during pumping of base emulsion ..........11

Mount Wright, Canada.............................................11

Middelburg Mine, South Africa .................................12

6. Accidents during handling of waste materials.........14

Argyle, Australia ......................................................14

France.....................................................................15

7. Conclusion.................................................................16

8. References.................................................................18

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1. Introduction Emulsion explosives have now been in use for about 40 years. The safety record for their manufacture, transport, storage and use in the UK has so far been good. More widely, though, a number of accidents involving emulsions have resulted in multiple fatalities, and the perception of emulsions as “safe” has recently been critiqued [Reference 1]. Emulsions

1 can be produced in both packaged and bulk form,

the latter now accounting for most of the production in the UK. Bulk emulsion is generally regarded as an especially safe type of blasting product. In fact, non-sensitized bulk emulsion that meets the criteria for inclusion in UN 3375 is not classed as an explosive under the UN scheme for the classification of dangerous goods for transport, but rather a Division 5.1 Oxidizing Substance to which Special Provision 309 applies

2.

Experience, however, shows that bulk emulsion can explode in the event of certain fault conditions arising in manufacture, transport and storage. It now seems timely to review the accident history for the manufacture, transport and storage of bulk emulsion. Such a review has recently been undertaken on behalf of the UK Health and Safety Executive, and this paper summarizes the results of that review. The information presented here is intended to help organizations identify potential accident scenarios that can arise during the above processes, and, most importantly, identify measures that might be implemented to reduce the risks inherent in these processes.

1 The type of emulsion that is the subject of this paper is bulk emulsion that

meets the criteria for inclusion in UN 3375 to which Special Provision 309 Part A of the UN Model Regulations applies. The paper does not discuss packaged emulsion or ammonium nitrate gels (the latter of which can also qualify as a UN 3375 product).

2 Current regulations (MSER) require that bulk emulsion produced in the UK

only be made on sites licensed by the Health and Safety Executive (HSE) for the manufacture of explosives, though bulk emulsion is not considered an explosive in the UK when it is transported and stored outside of the facility where it is made.

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It should be stressed that this paper is only concerned with incidents involving unsensitized bulk emulsion (incidents involving packaged emulsion are excluded). Some consideration is also given to incidents involving material that was ostensibly bulk emulsion but where, because of design, process or human error, the product was more sensitive than intended Accident information has been obtained from the SAFEX-EIDAS Database [Reference 2] and is reviewed under the following five headings:

1. Accidents during manufacture (emulsification) 2. Accidents during storage 3. Accidents during transport 4. Accidents during pumping operations

5. Accidents during handling of waste materials

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What are Emulsion Explosives?

Base emulsion consists of micro-droplets of super-saturated oxidizer solution within an oil matrix. The oxidizer comprises mostly ammonium nitrate, but sodium nitrate and calcium nitrate may also be added to the aqueous solution. The oil phase is a blend of mineral oil and liquid emulsifier. Oil and water normally do not mix, but when the appropriate emulsifier (surfactant) is present and enough mechanical energy is exerted, the two phases can be forced to blend together. The product so formed is an emulsion matrix in which the oil phase is continuous, i.e. each micro-droplet of the oxidizer is coated with an oily exterior. This intermediate product can be converted into an explosive by the addition of a sensitizer. Two types of sensitizers can be used: a physical sensitizer, comprising micro balloons; or a chemical sensitizer, comprising a gassing solution. Whichever method is used, the effect is to create microscopic gas bubbles that will adiabatically compress and produce hot spots within the bulk matrix following initiation of a booster – thus allowing the detonation wave to propagate throughout the bulk of the material. In terms of composition, base emulsions typically comprise:

60-85% ammonium nitrate; 5-30% water; 2-8% fuel; 0.5-4% emulsifier agent; 0-10% soluble flame suppressants; and trace additives. Other inorganic nitrate salts (usually sodium and calcium nitrate) may replace part of the ammonium nitrate.

To qualify for inclusion in UN 3375, a base emulsion must pass UN Test Series 8. This series comprises a thermal stability test [Test 8(a)], a gap test [Test 8(b)] and a burning tube test [Test 8(c)] [Reference 3].

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2. Accidents during manufacture of base emulsion

Details were obtained of five incidents involving the emulsification process, i.e. the process whereby the aqueous and non-aqueous components are forcibly blended together. All but one of these accidents occurred in China.

Kairuan, China Date: 26 May 1997 Casualties: 2 Killed, 2 Injured

Details of the incident An explosion occurred in a colloid mill that was used as an emulsifier. The explosion may have been caused by the presence of foreign matter or by friction between the rotor and stator.

Discussion of immediate and root causes Colloid mills operate at speeds of up to 2000rpm and produce emulsions that contain extremely small droplets of aqueous oxidizer [Reference 4]. The resulting product is likely to be sensitive and in the present case it is speculated that it was capable of being exploded by the frictional forces (or frictional heat) generated by a foreign object in the mill or between the rotor and stator. Although it is believed that the material produced was intended for use as a blasting intermediate, it would almost certainly not have passed the tests necessary for qualification as a UN 3375 product.

The above incident serves to illustrate the importance of good initial design of the production process. In the UK, colloid mills are not used for the purpose of producing base emulsion. The type of emulsifying equipment used varies from site to site, but it is considered that all this equipment produces base emulsion that is inherently less sensitive than that made in colloid mills. Nonetheless, the routine testing of products to ensure that they are within specification should be viewed as an important safety measure.

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Yongan, China Date: 7 May 1991 Casualties: 7 Killed 17 Injured

Details of the incident An explosion of base emulsion in the emulsifying kettle destroyed the production line and left a crater of radius 3.3m and 2.8m depth. The matrix was made by emulsifying the aqueous and oil phases under unusually strong agitation. The mixer paddle rotated at a speed of 851 rpm, whereas the original design speed was 450 rpm (a high agitation speed was required to achieve emulsification because of the choice of emulsifier – butane diaminimide). The ignition source in this incident was not clearly defined. Severe extrusion and friction due to the extraordinary agitation conditions may have resulted in local overheating, and this may have served as the initiation source. It is noteworthy that the operating conditions in this production line were abnormal because a new composition with much higher viscosity was being produced. This high viscosity composition was clearly unsuitable for mixing by the emulsifying equipment that was in use. The inner diameter of the emulsifying kettle was 600 mm and was operated at a temperature of 85-100 ºC; the system was thus well above the critical conditions for detonation propagation. Discussion of immediate and root causes It is postulated that the high agitation speed of the mixer resulted in a refined emulsion (small droplet size of aqueous and oil phases) and also possible air entrainment into the base emulsion. That the base emulsion was sensitized was subsequently verified by tests conducted by the investigation team. Under room temperature, cartridges of the emulsion (100 mm in diameter and 3 kg in weight)

were completely detonated by a single No. 8 detonator 3.

3 However, regular sized cartridges (32 mm in diameter) did not detonate

completely when initiated by a single No. 8 detonator as the critical charge diameter for this emulsion was well above 32 mm at room temperature. Experiments also showed that this critical diameter decreases significantly with increase of temperature.

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This above incident illustrates the potential for abnormally sensitive material to be produced when manufacture proceeds outside of the design parameters for the process. In general, excursion of operating parameters may result from human error or failure of automated process control systems. General accident experience has shown the potential for controls to fail during processing operations, though redundant systems can reduce the likelihood of overall failure to a low level. Further research might indicate to what extent abnormally sensitive material might be susceptible to initiation by impact or friction.

Dongfong, China Date: 5 January 1988 Casualties: None

Details of the incident A workshop and equipment were damaged by an explosion of base emulsion. The cause of the incident was attributed to: (1) the presence of residue in the emulsifier from a previous run; and (2) failure to cut off steam heating.

Discussion of immediate and root causes Failure to cut the steam supply probably led to the formation of a detonable product from the drying/crystallizing of the residue remaining in the bowl. It seems this residue was initiated (possibly as a result of impact or friction) during a subsequent production run, though it is not clear whether base emulsion was present in the emulsifier at the time of the incident, and, if so, whether it was effectively boostered by the detonable residue. In the absence of any details on the composition of the base emulsion, it is not possible to determine whether it would have met the criteria for inclusion in UN 3375.

Abest, Russia Date: 1 November 1990 Casualties: 6 Killed, 22 Injured

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Details of the incident An explosion occurred in a building in which components for emulsion explosives were mixed. The production unit and the pump truck were destroyed and a crater of 20m in diameter and 4.5m in depth was formed. The ferocity of the explosion is attested by the fact that the construction elements of the building were thrown about in the radius of 150-200m. Several adjacent buildings were damaged to various extents. Window panes fractured in the radius from 2.5-3.0km.

It is thought that the accident was the result of addition of dry sodium nitrite through the sampling hatch into the Poremit emulsion

4.

Discussion of immediate and root causes Under acidic conditions, the addition of sodium nitrite to the base emulsion would lead to the formation of nitrogen bubbles in the mix and subsequent sensitization. An energetic stimulus might then have detonated the sensitized product. However, an external stimulus would not even have been necessary to cause the explosion had sodium nitrite been added to the matrix in sufficient quantity. In this case the resultant exothermic reaction would gradually have speeded up and eventually triggered a runaway reaction. It is also possible that the addition sodium nitrite could have resulted in the formation of ammonium nitrite, which may then have subsequently decomposed explosively. In the absence of any details on the composition of the base emulsion, it is not known whether it would have met the criteria for inclusion in UN 3375.

Chongqing, China Date: 21 April 2005 Casualties: 12 Killed

Details of the incident At least 12 people were reported killed in an explosion at an emulsification workshop of Dongxi Chemical Plant. According to one report, the incident happened when lightning struck the building.

4 It is believed that a massive explosion which occurred at an emulsion

production facility in Zambia on 20th April 2005, and which resulted in the

deaths of over 40 people, may also have been caused by the inadvertent addition of dry sodium nitrite to base emulsion matrix. This suggestion, however, remains speculative.

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Discussion of immediate and root causes Only very scant details are available for this incident and the exact sequence of events leading to the explosion is a matter of conjecture. It is possible that the lightning strike started a fire (fuel fire perhaps) that then engulfed base emulsion in production equipment or storage vessels. The incident would then have unfolded in a sequence of events similar to that which occurred at Porgera (see below). It is stressed, however, that this is mere speculation.

3. Accidents during storage of base emulsion One record was found of an incident in which bulk base emulsion (believed to meet the criteria for inclusion in UN 3375) exploded after being exposed to prolonged heating in a tank. This incident has been discussed in a previous article published in Explosives Engineering [Reference 5].

Porgera, Papua New Guinea Date: 2 August 1995 Casualties: 11 Killed, 2 Injured

Details of the incident Mining operations at the Porgera gold mine were suspended following two large explosions at the explosives assembly area. The first explosion may have occurred in a mono pump during cartridging of Emulite (a cap-sensitive packaged emulsion explosive). The second explosion occurred about 75 minutes later and involved a bulk emulsion (which probably would have qualified as a UN 3375 product) stored in two metal silos (one of capacity 55,000 litres and the other of capacity 30,000 litres). It is believed this second explosion came about as a result of the first explosion rupturing an overhead fuel pipe and causing a fuel fire to develop in the bund below the base emulsion tank; the heat from this fire eventually caused the base emulsion to detonate.

Discussion of immediate and root causes In this case the heat from the fuel fire drove off the water content of the base emulsion, leaving a residue that comprised an intimate mixture of molten ammonium nitrate and fuel oil (in essence an ANFO-type composition). This began to decompose and on further

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heating the residue detonated. This end result occurred after the bulk base emulsion had been exposed to intense heat for a prolonged period (in excess of an hour); but in general the timing of such an outcome could depend on many factors, including type of composition, degree of confinement, type of heat source and rate of heating.

In addition to this incident, a paper recently published by SAFEX

[2]

refers to an incident in which a base emulsion transfer line exploded after a welder had set fire to vegetation underneath the line. The explosion did not propagate to bulk base emulsion contained in a 20 tonne silo. It has not been possible to obtain any further details for this incident; but it may be speculated that, as in the Porgera incident, fire degraded the base emulsion to produce a sensitive residue which then exploded on further heating. That the explosion failed to propagate suggests that the diameter of the pipe was below the critical charge diameter for the base emulsion, or possibly the pressure of the bulk emulsion was below the minimum burning pressure necessary for propagation to occur following initiation by a localized heat source.

Physical measures can be implemented that would practically eliminate the chance of fire developing around a storage tank. Furthermore, the tank could be constructed so that even if a severe fire did develop around it the contents would be released harmlessly and no explosion would occur. The feasibility of such a measure has been demonstrated by field trials undertaken in Sweden, which have shown that base emulsion contained in aluminium tanks can be released without violent reaction in the event of being engulfed by fire [Reference 6]. In such cases pressure relief is achieved as a consequence of the low tensile strength of aluminium at elevated temperatures – the tank material softens and opens non-violently,

allowing material to spill out and burn away.5

4. Accidents during transport of base emulsion Only one record was found of an explosive event occurring during transport of bulk emulsion.

5 Whilst failure of the aluminium tank does remove confinement, no studies

have yet been carried out to assess the potential hazard of molten aluminium reacting with the bulk matrix.

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Usmanka, Russia Date: 14 June 2004 Casualties: None

Details of the incident A truck carrying base emulsion exploded on the highway following spread of heat from a tyre fire on the vehicle. According to the Russian authorities, the tank on the truck had not been properly cleaned between runs and this had allowed crystallized residue to form on the bottom of the tank. This residue detonated when heated.

Discussion of immediate and root causes Loss of water from the emulsion would have produced a residue that contained an intimate mixture of solid nitrate and oil (akin to ANFO). This crust resulted in poor heat conduction and local overheating and decomposition of the residue. Had the tank not been crusted, the matrix would have boiled and convective currents would have distributed the heat more evenly throughout the bulk of the matrix.

In the absence of compositional details, it is not possible to determine whether the base emulsion would have met the criteria for inclusion in UN 3375. Nonetheless, this incident does suggest that such products may be much more susceptible to accidental explosion when contaminated with crystallized residue. Experience would suggest that all bulk emulsions are susceptible to explosion under prolonged heating, but the time to explosion could be influenced by many factors, such as composition, degree of confinement, heat source and rate of heating.

5. Accidents during pumping of base emulsion Records were found for two incidents in which bulk emulsion (believed to meet the criteria for inclusion in UN 3375) exploded following exposure to prolonged heating in pumps.

Mount Wright, Canada Date: 18 April 1990 Casualties: None

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Details of incident About 5-15 minutes following the transfer of base emulsion from one bulk truck to another, an explosion occurred in the barrel of a Netzsch progressive cavity pump that had been used in the transfer operation. The operative was uninjured as he had left the vehicle after completion of the transfer.

Subsequent investigations showed that the pump had run dry for several minutes prior to the operative leaving the truck and evidence was found that that the pump continued to operate after the operative had left. Several pieces of the rotor of the pump were recovered and confirm an internal event.

Discussion of immediate and root causes The material involved in this incident was a standard bulk base emulsion, i.e. a UN 3375 product. The welding on the hollow rotor failed allowing product into the cavity. Dry running of the pump caused progressive heating of the emulsion in the cavity and over a period this decomposed. Eventually the residue exploded thermally, but the event was relieved by the soft bend at the pump exit. The product pump was provided with two safety measures – a 5-minute timer and a decounter – but both measures were bypassed since the pump was being used as a transfer pump and resetting was annoying to the operatives. Hollow rotor pumps were subsequently banned.

Middelburg Mine, South Africa Date: 5 November 2002 Casualties: 1 Injured

Details of incident During the process of transferring bulk base emulsion from a truck to a storage silo, the progressive cavity pump used in the transfer operation exploded. The operative was alone when the incident happened and was severely injured in the explosion (wounds to his face, abdomen, right leg, right eye and both hands). Shrapnel pieces from the pump were recovered as far as 200 meters from the site. Two reports of this incident give slightly different accounts of the exact sequence of events.

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According to one report the transport operative fell asleep in the cab of the vehicle during the transfer operation (he had been on duty for almost 24 hours). This resulted in the pump running dry for a period of at least one hour. The elevated temperatures and pressures generated in the pump led to the concentration and subsequent decomposition of the emulsion in the casing. Once started, this auto catalyzing decomposition ultimately led to the detonation of the residue in the pump casing (estimated to be about 2kg).

According to another report the transport operative fell asleep in the cab of the vehicle for several hours. When he awoke he noticed that the transfer operation had completed and so then moved the transfer pipe to the other emulsion tank on the vehicle. Within a few minutes of restarting the pump, a detonation occurred which blew up the pump and part of the discharge pipe. It is estimated that about 2kg of explosive detonated. This account of the incident suggests that the pump had run dry for a considerable period of time (3 hours) after the contents of the first tank had been discharged and that the temperature of the pump had risen in this time to a high level. The explosion occurred when fresh emulsion entered the hot pump. A rapid increase in temperature of the emulsion confined within the pump resulted in a sudden increase in pressure, which led to the product detonating. Discussion of immediate and root causes It is clear that this incident was caused by heating of emulsion in a pump that had run dry. It is probable that the heat caused part of the bulk emulsion to degrade, leading to the formation of a sensitive residue that then started to decompose and which ultimately detonated. In any event, the pump overheated as a result of operative error and there were no automatic safeguards (high-temperature or high-pressure trips) to prevent an explosion occurring

A report of the incident by AEL makes a number of salient points about the hazards posed by bulk emulsion:

“Emulsion matrix is classed as non-explosive in its manufactured state. The safety systems in transporting the product and storing it were built around this property. The current state of the product, when changed, can make it an explosive under extreme conditions. The incident indicated that mechanisms do exist in the handling operations to transform the base emulsion into a sensitive explosive given the right conditions. These conditions include high

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temperatures and pressures which are aggravated in a no-flow-of-product situation when the product is pumped”.

Such incidents can be prevented by the installation of protective measures to prevent dry-running and dead-heading of pumps. Such measures include:

• Installation of thermal trips on pumps

• Installation of pressure trips on pumps • Installation of flow sensors on pumps

• Installation of thermal and pressure high/low audible alarms

• Installation of batch pumping systems (timer and level cut outs)

It is noteworthy that in both the Mount Wright and Middelburg incidents, the explosion did not propagate from the pump to bulk explosives in trucks or storage silos. It may be that in both these incidents the diameter of the discharge pipe was less than the critical charge diameter for the base emulsion.

6. Accidents during handling of waste materials Records were found for two explosives events occurring during disposal of what is believed to have been waste base emulsion.

Argyle, Australia Casualties: 2 Injured Date: 25 May 1995

Details of the incident Two employees were injured, one seriously, when a container of waste products exploded. Investigations revealed the cause to be the mixing of sweepings of emulsion (believed to be base emulsion) and also ammonium nitrate and rags with a highly concentrated solution of sodium nitrite. This inadvertent mixing came about in the following way:

Prior to the incident an empty container was required for sweepings

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of base emulsion and ammonium nitrate. An employee on viewing the containers in the area mistakenly believed that one holding a solution of sodium nitrite contained ammonium nitrate solution and, therefore, there would be no problem in adding the sweepings to it. Two hours after the mixing of the products, smoke was observed coming from the container and whilst approaching the area with extinguishers two employees were exposed to the explosion.

Discussion of immediate and root causes The cause of this incident is very similar to that described for the Abest incident. The sodium nitrite reacted exothermically with the ammonium nitrate, the speed of the reaction gradually building as the temperature increased, and eventually led to a runaway reaction and explosion.

This incident also highlights the importance of training in waste disposal procedures and the need for correct action to be taken in emergency situations: persons should be immediately evacuated from the vicinity of fuming or smoking chemicals – “flight not fight”. The incident also illustrates the need to ensure that sodium nitrite is stored remotely from emulsion and ammonium nitrate.

France Date: 12 March 2001 Casualties: None

Details of the incident When emptying waste bins in a production unit, an operative inadvertently mixed waste thermite composition (reported as consisting of aluminium, alum and copper oxide) with “mother emulsion” (assumed to be base emulsion). A deflagration followed.

Discussion of immediate and root causes The report indicates that the “mother emulsion” had crystallized, in which case the material might have been more like ANFO. Copper in the thermite composition may have reacted with ammonium nitrate to form the tetramine complex, Cu(NH3)4(NO3)2, which can decompose explosively when strongly heated. In the absence of compositional details, it is not possible to determine whether the base emulsion would have met the criteria for inclusion in UN 3375.

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7. Conclusion The past accident review uncovered details of 11 incidents in which base emulsion exploded after being excessively heated or mixed with incompatible materials. Although some of these incidents involved base emulsion that would not have met the criteria for inclusion in UN 3375, the details of these incidents nonetheless pinpoint a number of ways in which blasting intermediates may accidentally explode in the manufacturing, transport and storage environments. The accident record also suggests that bulk emulsion, when properly manufactured and tested to UN 3375, is not prone to initiation by mechanical forces, inasmuch as no record has been found of an explosion caused by the exposure of bulk emulsion to either impact or short exposure to friction and nipping. Of the 11 incidents examined, eight occurred on manufacturing sites, two occurred in storage/end-user sites and one occurred in transport. The review thus suggests that the greatest potential for inadvertent initiation lies in manufacture. The potential causes of accidental explosion in manufacture identified in the review are as follows (not in order of importance):

1. Bad design of manufacturing process leading to production of abnormally sensitive material

2. Production outside of design parameters leading to manufacture of abnormally sensitive material

3. Poor housekeeping leading to formation of sensitive residues consisting of dried/crystallized base emulsion

4. Fire engulfment and prolonged heating of base emulsion in metal silos/tanks

5. Localized heating of base emulsion in dead-heading and dry-running pumps

6

6. Contamination of base emulsion with incompatible materials

6

Although the two pumping incidents examined in this past accident review

occurred on end-user/storage sites, there is also a potential for such incidents to occur on manufacturing sites.

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There are many controls that can be implemented to reduce the likelihood of accidents arising from these causes. Guidance on general explosives safety is given in the Approved Code of Practice to the Manufacture and Storage of Explosives Regulations and the MoD Explosives Regulations (JSP 482: Ministry of Defence Explosives Regulations). Measures for reducing the risks of emulsion manufacture have been reviewed in a recent SAFEX publication [Reference 1].

Implementation of appropriate controls can help reduce risks to a low level and constitute an important component of safety management. However, experience suggests that even with the best controls in place, manufacturing operations will always present a residual risk – due to the potential for human error and equipment/instrumentation failure. The question is whether the residual risk has been reduced as low as reasonably practicable.

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8. References

1. Begg A H, Hazards in Emulsion Explosives Manufacture and Handling, SAFEX Topical Papers Series, Paper No 05/2008, August 2008

2. Moreton P A, Lang G L and Sexstone P A, The Explosives Incidents Database Advisory Service (EIDAS), Minutes of the Twenty-seventh Explosives Safety Seminar, Las Vegas, Nevada, US Department of Defense Explosives Safety Board, 1996.

3. United Nations, Recommendations on the Transport of Dangerous Goods, Model Regulations (Fifteenth revised edition), New York and Geneva, 2007

4. Halliday P (AEL), personal communication to Moreton P A (MBTB Ltd), 2008

5. Sen G C and Downs G, Strategic training to avoid explosives-related accidents in mining, Explosives Engineering, September 2008.

6. Karlström R et al, Full-scale Fire Test of ANE Matrix in Aluminium and Stainless Steel Tanks, Paper presented to 16

th SAFEX Congress, Madrid, 2008

About SAFEX International

SAFEX International is a global organisation with the fundamental objective of improving the safety of

operations and their impact on people and the

environment. Operations cover the development, manufacture, storage, and transport of commercial

explosives, military explosives and pyrotechnic

products throughout the world. The term “explosives” includes initiating devices, propellants,

industrial and military powders as well as the raw

and intermediate materials associated with the explosives industry.

Current membership of SAFEX is over 100

companies from all the continents in the world and operating in more than 40 different countries.

SAFEX is a non-profit making association of

manufacturers of explosives and was founded in

1954 with the aim of exchanging experiences within the explosives industry. The way SAFEX works is to

exchange health, safety, and environmental (HS&E) information about major accidents, serious incidents,

and near-hits. The objective is to avoid other

manufacturers experiencing the same or similar events. In this way SAFEX contributes to improving

the health and safety of operations within the

explosives business as well as the well-being and standing of the explosives industry. As a voluntary

organisation, SAFEX is not organised for the

pecuniary gain of any of its members.

SAFEX International is registered in Switzerland as an international association operating not for profit

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