Publication No. 21
DISPOSAL OF SMALL QUANTITIES OF BLASTING EXPLOSIVES IN THE FIELD
CONTENTS
INTRODUCTION
1.GENERAL INSTRUCTIONS
1.1Disposal by Detonation
1.2Disposal by Burning
2.SPECIAL INSTRUCTIONS
2.1Packing Materials
2.2Nitroglycerine Based Explosives
2.3TNT Based Explosives
2.4Water Based Explosives (Slurries and Emulsions)
2.5Ammonium Nitrate Fuel Oil Explosive
2.6Black Powder
2.7Igniter Cord
2.8Safety Fuse
2.9Detonating Cord
2.10Detonators and Devices
3.SECURITY
THE PROCEDURES OUTLINED IN THIS CODE OF GOOD PRACTICE COVER THE DESTRUCTION OF SMALL QUANTITIES ONLY, UP TO 25 KG OF EXPLOSIVE IN TOTAL OR 50 DETONATORS.
IF THE QUANTITY EXCEEDS THIS OR THE STOCK IS IN A DETERIORATED AND/OR DANGEROUS STATE THEN THE MANUFACTURER SHOULD BE CONSULTED REGARDING THE DISPOSAL.
SOME SPECIAL EXPLOSIVE DEVICES IN WHICH EXPLOSIVES ARE CONTAINED IN METAL CONTAINERS OR MACHINED METAL PARTS CONSTITUTE PARTICULAR HAZARDS WITH REGARD TO SHRAPNEL. EXAMPLES OF EXPLOSIVES IN THIS CATEGORY INCLUDE SOME SHAPED CHARGES, SOME WELL PERFORATING CHARGES, EXPLOSIVE BOLTS AND OTHER DEVICES IN WHICH THE EXPLOSIVE IS CONTAINED IN A MACHINED METAL CONTAINER. IN THESE CIRCUMSTANCES DESTRUCTION OF THE PRODUCTS SHOULD ONLY BE UNDERTAKEN AFTER CONSULTATION WITH THE MANUFACTURER.
INTRODUCTION
There are occasions when it will become necessary to dispose of explosives. These occasions arise when the explosive is deemed unfit for normal use and cannot be safely transported. Disposal may also become necessary when no storage or transport facilities for surplus explosives are available or loose explosive cannot be packed for transport according to regulations.
In these circumstances the Federation of European Explosive Manufacturers strongly advise that the action taken takes the following factors into consideration in the listed order of priority.
1.Safety of personnel
2.Safety of property
3.Environmental considerations.
When handling explosives, particularly unfit explosives, safety must be the principal consideration.
Consequently it is essential that anyone entrusted with the task of disposal be properly qualified and at least knowledgeable about the products to be disposed of and properly instructed in safe methods of disposal. This Code of Good Practice has been prepared in order to assist in the proper instruction of operators in this operation.
Burning small quantities in the open has been practised for many years. This method is safe provided the instructions, and particularly the precautions, are followed and the temptation to take shortcuts avoided.
There may be occasions, however, when there are objections to disposal by open burning in which case alternative methods of disposal must be sought whilst still maintaining the overriding need for that method to be safe.
On these occasions disposal by incorporating limited quantities of the explosives to be destroyed into a production blast is the safest method, again providing the limitation on quantities and safety precautions are strictly adhered to.
Provided the site is remote and sufficiently large, provided local conditions and regulations permit it,burningdetonating small quantities in the open on a specially designated area on the site can bea satisfactory method of disposal
UNDER NO CIRCUMSTANCES SHOULD WASTE EXPLOSIVES BE BURIED AS A METHOD OF DISPOSAL.
1. GENERAL INSTRUCTIONS
In today's environmentally conscious climate great care has to be taken to ensure that disposal is carried out safely and with the minimum disturbance to the environment.
There are two ways of safe disposal of small quantities in the field:
1.By detonation
2By burning.
In both cases the operation should only be carried out by a suitably qualified person.
1.1DESTRUCTION BY DETONATION
Whilst destruction of explosive by detonation is a relatively simple operationit can only be carried out safely where blasting operations are routinely performed. Destruction by detonation is particularly to be recommended for explosives which are filled into rigid cartridges and which could present a risk of detonation if burnt in their containers.
1.1.1Small quantities of explosive may be incorporated in a normal blast, loading them into the shothole as part of, but on top of the standard charge and fired with the rest of the round. The quantity in each shothole should be limited to ensure that its addition does not give rise to fly rocks or otherwise interfere with the blasting results5% of the designed charge per hole otherwise it may interfere with the blasting result.
1.1.2The loading of explosive materials into shotholes should only be carried out under the supervision of a qualified shotfirer with the approval of the responsible person in charge.
1.1.3The blast should be carried out in accordance with the recommendations made in the FEEM Code of Good Practice - "Blasting"
1.1.4Nitroglycerine Based and Water Based Explosives
These types of explosives may be destroyed by detonation in the open. However, it cannot be over-emphasised that there are two major hazards associated with open detonation. These are:
1.The possibility of airblast damaging property in the vicinity.
2.The danger of a missile effect from loose material such as stones etc. surrounding the charge.
Great care must be taken in order to minimise the hazard presented by either of the above conditions. The following rules are of a general type and in no way replace the expert judgement and experience of the operator involved nor his responsibility to ensure that no damage or hazards are created.
(a)It is emphasised that blasting in the open involves environmental factors of noise and overpressure which must be taken into consideration. The operator must assess the hazard and the consequences of firing in the open. taking into account local conditions.
(b)In the open on the ground a primer charge whose size should be at least 20% of the quantity of explosive to be destroyed and located centrally in the charge should be used.
(c)The total charge should be covered (capped) with an adequate layer of fine material (such as sand) sufficient to confine the charge and which should in no circumstances be less than 0.5m thick.
(d)Great care must be taken to ensure that there are no stones or other material which could have a missile effect.
Small quantities of permitted explosives can also be destroyed by controlled detonation by confining the charges into cardboard tubes or thin walled plastic cylinders.
A preferred procedure is to incorporate the explosives in a standard blast observing all the normal blasting procedures as detailed in the FEEM Code of Good Practice on" Blasting " .
(a)The explosive may be included with theadded to borehole explosive charges in proportions not exceeding about 5% of the total charge.
(b)Extra care must be taken to ensure transmission of detonation over the full charge length, e.g. by using multiple priming or downhole detonating cord.
1.1.5Explosives of Powder Consistency
(a)Explosives of powder consistency that have become wet may be detonated by overlaying them with the same quantity of good quality explosive and detonated with an appropriate detonator.
(b)Dry powder explosives may be destroyed by detonation as part of a borehole or chamber explosive charge in the same way as for nitroglycerine based explosives.
1.1.6Detonators and Delay Detonators
Great care must be taken in any attempts to destroy detonators to ensure that destruction is complete.
Instances exist where detonators have survived large blasts without themselves being detonated and being scattered considerable distances.
Detonators for destruction should be considered in two categories
(a)Those in good condition and
(b)Those which are judged to have deteriorated.
Detonators in any condition can be destroyed by insertion into a cap sensitivenitroglycerine based explosive Cartridge charge so that each detonator is completely immersed in the explosive. Up to 10 detonators may be destroyed in this way, the charge being initiated by an appropriate detonator and covered with a layer of fine material at least 0.5m deep to prevent flying debris.
Detonators in good condition may also be destroyed in groups of six with their bases in contact with each other and surrounding the firinga sound detonator. It is important to restrict the number to six items because this is the maximum number that can be arranged around a detonator without leaving a gap. The arrangement should be adequately covered in a layer of material at least 0.5m deep.
Another method for destroying detonators of doubtful quality is to wrap them with heavy duty detonating cord and initiate the assembly. Again, the assembly must be buried under a suitable depth of fine material.
It is essential to check if all detonators have been destroyed and accounted for.
1.1.7Shock Tube Detonators
Shock tube detonators can be destroyed by first cutting off the shock tube. Thereafter, the detonator can be destroyed by the above mentionnednormal methods. The shock tube can be destroyed by open burning in the same way as other explosive materials. It must always be remembered that the shock tubecontains pyrotechnic compositionsexplosive.
1.1.8Detonating Cords
Detonating cord can also be destroyed by detonation.
When the core of detonating cord becomes wet it may become insensitive to initiation by detonators. In this case it is preferable to destroy the cord material by incorporating it in a borehole during the blast with normal material. If this is not possible, then consideration should be given to burning it rather than attempting to detonate it.
1.1.9Detonating Devices and Assemblies
Explosives or detonating devices, especially those devices which incorporate metal or plastic containers, other than those enumerated above should be destroyed under the supervision of the manufacturer or supplier.
1.2DISPOSAL BY BURNING
It should be recognised that, although burning is a common method of destroying explosives, there is the danger of the process changing to detonation and precautions should be taken accordingly.
IT MUST BE EMPHASISED THAT WHEN EXPLOSIVES OR CONTAMINATED PACKING MATERIALS ARE BEING DESTROYED BY BURNING, ALL PERSONNEL MUST KEEP AWAY FROM THE BURNING SITE AND IN A SAFE SHELTERED POSITION IN CASE AN EXPLOSION OCCURS.
The following procedures are suggested: -
1.2.1The total quantity burned should be strictly limited to not more than 25 kg in total and no more than 2.5 kg per pile at any one time to minimise any environmental effect in the event of an explosion.It is essential to estimate the risk to third parties when deciding the actual weight of explosives in each pile
1.2.2Any burning site must be so located that a burning to detonation incident will not cause problems. The site must be specially prepared and should be screened or have some natural protection. In the absence of such protection, special attention must be paid to the safety distance. Hazard of grass fires must be minimised. This can be done by ensuring that the site is cleared of grass in the area of burning.
1.2.3The site should be free from loose stones, ashes from previous burnings, metallic and other debris and high grass. Burning sites should be kept in an orderly fashion and cleaned up at regular intervals.
1.2.4The burning site should be securedguarded to prevent unauthorised entry.
1.2.5Once a fire has been ignited it should NOT be approached again until it has COMPLETELYBURNEDOUT. A good safety margin should be allowed after all evidence of burning has ceased.
1.2.6All tools used for preparation and spreading the explosive should be non-sparking.
1.2.7DIFFERENT KINDS OF EXPLOSIVE MUST NOT BE BURNED ON THE SAME FIRE.
1.2.8Special care should be taken to ensure that no detonator is present with or in the explosive.
1.2.9The explosive should be spread out in small lots not exceeding 2,5 kg each, depending on site restrictions,and up to a total of 25 kg. Each lot should be limited to only one layer of cartridges with a thickness not exceeding 50mm. This layer must be placed on a bed of combustible materials such as paper or wood. Larger diameter cartridges should be cut to conform with this requirement.
1.2.10The lots should be connected by a train of combustible materials and the explosive and train well sprinkled with kerosene, diesel, or other combustible oil before ignition.
1.2.11Low flash point fuel (such as petrol/gasoline) should NOT be used in the train.
1.2.12 Each lot should be separated from its neighbour by a distance which will ensure that any accidental detonation will not propagate from pile to pile.
The following table indicates the minimum appropriate distance between separate piles:-
IndividualPile
kg / Distance
Pile/Pile
m
0,1 / 1
0,25 / 2
0,5 / 3
0,5 to 2 / 5
2,5 / 6
1.2.13The distance from the burning site to the nearest building, operation or place where other personnel are working without specific protection should be at least 300 metres.
1.2.14The burning ground must be free from hot spots from previous activities, if necessary dampened with water first.
1.2.15Great care should be taken if burning is carried out in windy or wet weather.
1.2.16All personnel should be withdrawn from the burning site and in a position of safety before any attempt is made to ignite the train.
1.2.17The train should always be ignited against the wind to ensure controlled burning.
1.2.18As soon as the train is ignited the operator must retire immediately to a safe sheltered position so that he is in no danger if a detonation should occur.
1.2.19Any explosive found remaining after the fire must be handled with EXTREME care, because the explosive may be in a more sensitive state than usual.
1.2.20Steps must be taken to ensure that all combustion has been extinguished
AND THE GROUND COOLED before a second fire is built. Where possible the area should be well watered after each fire.
1.2.21UNDER NO CIRCUMSTANCES SHOULD ANYTHING BE ADDED TO A FIRE ONCE IT IS BURNING.
1.2.22Ashes from the fire should be collected and subsequently buried.
1.2.23It should be noted that in the event of an explosive burning to detonation, peak overpressure may cause a problem, and this should be taken into account when the overall safety of the operation is being assessed.
2. SPECIAL INSTRUCTIONS
2.1PACKING MATERIAL
2.1.1Packing materials, linings any other material contaminated by explosives can be disposed of by burning. It can be conveniently used as a combustible base for other burning operations.
2.1.2All cases and other packing materials should be carefully inspected to ensure that there is no explosives remaining in the case before burning.
2.1.3If packing material is to be disposed of separately, the precautions laid down in paragraphs 1.2.16 to 1.2.23 should still be followed.
2.1.4In windy weather precautions should be taken to ensure that burning material is not blown about. If necessary, some form of brazier burning should be adopted.
2.2WATER BASED EXPLOSIVES (SLURRIES AND EMULSIONS)
The preferable method for destruction of water-based explosives is detonation but if this is not possible and burning is to be employed it must be remembered that, because these do not burn as readily as either of the above types, substantial quantities of a combustible base such as wood and kerosene will be essential to ensure complete destruction.
2.3AMMONIUM NITRATE/FUEL OIL - ANFO AND ALUMINOUS ANFO
2.3.1If prepared on site ANFO can be readily disposed of by detonation as part of a routine blast.
2.3.2ANFO is particularly easily destroyed by dissolving in copious quantities of water. The wash waters must, however, be regarded as chemically contaminated effluent and disposed of in an appropriate manner.
2.4BLACKPOWDER
Small quantities are best disposed of by burning.
2.4.1It must be remembered that unconfined Blackpowder is a burning composition which is very easily ignited and burns very quickly. Special care has therefore to be taken. Care should be taken to avoid the possibility of a fireball being produced.
2.4.2It is very important to ensure that the powder is not confined in any way as this can lead to rapid decomposition, approaching detonation. The powder should, therefore, be removed from any wrapper or container before burning.
2.4.3Disposal should be by burning in the open by placing the material in long "snakes" not exceeding 5 cm deep and so positioned that a train will not burn across and prematurely ignite other parts of the train.
2.4.4The train should be ignited from a safe distance, preferably by electric means.
2.4.5Care must be taken to ensure that the loose powder does not blow about. It is therefore advisable to choose a place well protected from the windthat a calm day is chosen andand to damp the loose powder should be well dampened with kerosene or other combustible oil.
2.5IGNITER CORD
Igniter cords are best disposed of by burning.
2.5.1Igniter cords burn with an intense flame and should be treated with the same care and attention as Blackpowder.
2.5.2Particular attention should be paid to the fact that they can produce a "fireball" effect not dissimilar to Blackpowder.
2.5.3Igniter cords should be prepared for burning by cutting into short lengths, e.g. not exceeding 1m, and using clean cutters.
Prepared lengths should be placed on a bed of paper or wood shavings, not exceeding 10 lengths of cord per pile.
Igniter Cord Fast compositions burn extremely rapidly and burning lengths may be ejected into areas surrounding the fire.
For this reason it is important to ensure that the surrounding area is free from any flammable materials such as dry grass etc.
Some igniter cords contain reinforcing wires made from copper, steel or aluminium. Care should be taken to ensure that these have cooled down before their disposal.
2.6SAFETY FUSE
2.6.1When there is a need to dispose of safety fuse it should be taken off the reel and burned in the usual way.
2.7DETONATING CORD
The most convenient method of destroying detonating cord is by loading it along with other explosives in a standard blast; and no attempt should be made to dispose of bulk quantities of detonating cord by burning.
Scrap ends of detonating cord may be destroyed by open burning but great care should be taken to ensure that metal caps are removed from any scrap ends being burned.
2.8DETONATORS AND DEVICES
.
The manufacturer should be contacted and arrangements made for destruction by or under specialist supervision.
ON NO ACCOUNT SHOULD ANY ATTEMPT BE MADE TO DISPOSE OF DETONATORS, SURPLUS EXPLOSIVES, OR DEVICES BY BURNING OTHER THAN THOSE DESCRIBED ABOVE
3. SECURITY
ALL DISPOSAL OPERATIONS SHOULD BE SUBJECT TO THE SAME CAREFUL ACCOUNTING AND RECORDING PROCEDURES AS ARE FOLLOWED FOR THE MAGAZINING AND ISSUING OF EXPLOSIVES FOR NORMAL USE. THE QUANTITIES AND TYPES DISPOSED OF SHOULD BE PROPERLY REGISTERED AND THE REGISTERS SIGNED BY THE PERSON RESPONSIBLE UNDER THE LICENCE OR AUTHORISATION.
If there is any doubt whatsoever about the correct method of disposal then the supplier or manufacturer should be contacted without delay for his guidance and assistance.