Working with Explosives Material
An Explosives Material, also called an explosive, is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound and pressure. An explosive charge is a measured quantity of explosive material. We can categorize into the following categories:-
Gunpowder, Fireworks, cordite.
Industrial Explosives Material
Industrial Explosives are of two types:-
- Detonator sensitive or primary explosives: Can be initiated by the standard detonator for example: Dynamite, blasting gelatin, Anzomex, packaged emulsion.
- Blasting agents: Individual ingredients non- explosive cannot initiated by the detonator primary Explosive charge required. E.g. ANFO (ammonium nitrate -fuel oil) emulsion, slurry.
These are used by the military E.g. TNT (trinitrotoluene), PETN (Pentaerythritol tetranitrate), HMX, and Semtex.
Characteristics of Explosives Material
The standard qualities a compound or mixture must possess to qualify as an explosive include:-
- Rapid expansion of gases.
- Generation of heat due to the exothermic reaction
- When ignited, explosives can be controlled in terms of rapidity and initiation of the reaction.
- Explosives must have limited amount of toxicity.
Industrial Explosives Material and Its Uses
ANAL (Ammonium Nitrate and Aluminum powder)
- Ingredients:- AN , AL powder and Fuel oil
- Sensitivity:- Sensitive to heat but not shock and frication.
- Uses:- Certain commercial blasting explosive and especially water – based slurry explosive.
ANFO (Ammonium Nitrate and Fuel Oil)
- Sensitivity:- Relatively incentive to heat, shock and frication.
- Uses:- It uses in primarily in mining and quarrying operations
- Precautions:- Due to ANFO’s insensitivity and because mixing AN and fuel oil is relatively safe, special precautions are not required when handling
- Alternative names:- Gun powder or grain powder.
- Appearance:- Color ranges from coal black to cocoa brown, granularity vary from fine to coarse.
- Sensitivity:- Extremely sensitive to heat, shock and friction.
- Uses:- it uses in the core of military and commercial safety fuses and also used in the fireworks, model rocket engines, and ammunition propellant.
- Appearance:- Light brown to reddish-tan; texture is loose, moist, and oily.
- Sensitivity:- All dynamite is sensitive to heat, shock, and friction.
- Uses:- Commercial dynamite is used for construction, demolition, road building, and mining.
- Alternative names:- 1,2,3- Propanetriol trinitrate, glycerol trinitrate, nitro glycerol, NG, trinitro glycerol, NTG, trinitrin, blasting oil, and trinitro glycerin
- Appearance:- Colorless oily liquid when pure, but turns a yellowish-brown when impure and Sweet burning smell.
- Sensitivity:- Extremely sensitive to heat, shock, and friction.
- Uses:- Can be used with nitrocellulose in some propellants, especially for rockets and missiles
- Appearance:- Small grains or pellets, not powder and Shapes can include cylinders, flakes, disks, balls, flattened balls, agglomerates, and strip shapes
- Sensitivity:- Sensitive to heat, shock, and friction.
- Uses:- Used in mortar shells, artillery shells up to 280 mm, and as the propellant charge in naval artillery.
- Appearance:- Pale yellow solid compound in its basic state; odorless.
- Sensitivity:- Moderately sensitive to heat; relatively insensitive to shock and friction.
- Uses:- Primarily mines and demolition explosives and Also used in booster explosives and missile and rocket propellants.
- Alternative name:- Acidogen nitrate
- Appearance:- Colorless crystals or white powder with strong ammonia or urine-like odor.
- Sensitivity:- Not sensitive to heat, shock, or friction
- Uses:- Used and manufactured for agricultural fertilizers, chemical de-ices, plastics manufacturing, and military bombs.
Basic Explosives Material Hazards
There are two main hazards from an explosion, heat and blast.
- Heat:- Which is created by the chemical reaction. Heat precedes the blast effects. Heat may produce thermal burns.
- Blast:- A rapid generation of high pressure from the released gas can create a shock wave which is commonly called blast.
Safety rules when working with the Explosive Material
We must follow the following steps:-
Step 1:- Identify the fire and explosion hazards and hazards from similar energetic events
The supplier’s Material Safety Data Sheet should provide key information on the properties and hazards of the dangerous substance to assist you in this task. It should also provide information on the safe methods for the storage, use and handling of the dangerous substance, or make reference to where this may be found.
Step 2:- Decide who might be harmed and how
Identify the people at risk from the, explosion hazards or similar energetic event involving the dangerous substance. Based on your consideration of the anticipated effects of the incident, determine who might be potentially harmed by it. This includes members of the public who might be put at risk by the work activity.
Step 3:- Evaluate the risks and decide on precautions
This should take account of such things as:
- The possible substitution of the dangerous substance by one that is non-hazardous, or one that is less hazardous.
- The control measures to prevent a fire, explosion or similar energetic incident from occurring.
- The mitigation measures to limit the scale and magnitude of the incident should it occur.
Step 4:- Record your findings and implement control measures.
The risk assessment should also help you decide on:-
- The information, instruction and training you give to your employees. This should be sufficient for them to safeguard themselves and others from the risks presented by the dangerous substances.
- The arrangements to deal with accidents, incidents and emergencies, including involvement of the emergency services.
Step 5:- Review your risk assessment and update if necessary
If you introduce significant changes to your workplace, such as changing the dangerous substances present or their quantities, or changing the work equipment or processes, you should review your risk assessment.
You should carry out a risk assessment regardless of the quantity of dangerous substance present, as it will enable you to decide whether existing measures are sufficient or whether any additional controls or precautions are necessary.
- Priorities your control measures as follows:
- Reduce the quantity of dangerous substances to a minimum;
- Avoid or minimize releases of dangerous substances;
- Control releases of dangerous substances at source;
- Prevent the formation of an explosive atmosphere, including by ventilation;
- Collect, contain and remove any releases to a safe place;
- Avoid ignition sources;
- Avoid adverse conditions (such as exceeding pressure/temperature limits) that could lead to danger;
- Keep incompatible substances apart.