Home / Technology / Energy & Propulsion / Green Energetic Materials and Munitions technologies with enhanced environmental and occupational safety

Green Energetic Materials and Munitions technologies with enhanced environmental and occupational safety

Energetic materials and munitions are used across DoD in mission critical applications such as rockets, missiles, ammunition, and pyrotechnic devices. In these applications, energetic materials and munitions must perform as designed to ensure success in both training and combat operations.


In these applications, energetic materials and munitions must perform as designed to ensure success in both training and combat operations. Every time a gun fires, lead leaches into the air. A past study found that people who have been shooting a lot could have elevated lead levels. But so far, the use of lead in explosives has been inevitable. A scientific advancement could provide a comparable replacement for lead-based explosive materials found in ammunition, protecting soldiers and the environment from potential toxic effects.


There are, however, potential environmental, occupational safety and health risks associated with these materials. Munitions generate significant air emissions when they are used or demilitarized. The amounts and composition of these emissions must be determined to enable military installation managers to comply with environmental regulations and obtain permits to continue mission-critical activities. Projects aim to quantify the emissions created when munitions are used in normal operation or when they are demilitarized using techniques such as open burning and open detonation.


Life cycle perspective

Most of the munitions are not used in war scenarios but are either used in training or disposed of,  hence whole life cycle thinking is required including the  production of munitions, the use phase and the disposal of munitions


When looking at the environmental impact of the whole life of munitions, the overwhelming largest part of the impact comes from the manufacturing process. Apart from the manufacturing phase the end of life is the second most environmentally important phase. In most cases the end of life has only a small environmental impact due to diligent handling of the end of life. Beside these two stages the storage and transportation phases need to be considered even though their contributions are small in this context


Mitigating these risks throughout the life-cycle of these materials is costly and time-consuming. However, China since 2011 has been building weapons with CL-20, an energetic material invented in the United States 35 years ago that produces less visible exhaust, but that we ourselves have not used operationally because of production and environmental challenges.


We need to think about where the materials we use comes from, are they abundant, do they demand a large amount of energy etc. Other relevant questions are how the materials are produced, how they are used in the munitions, how the munitions are going to be used and the end of life phase.


Choices of materials and designs, in the beginning, can have very large impacts in later stages. The design of the munitions is crucial for how well and safely it can be disassembled. Disassembly is critical for the recycling, recovery, and reuse of the different constituent materials.


Another issue that also needs to be addressed in the life cycle perspective is that munitions should not cause any environmental problems after use. This applies both in terms of safety, considering the problem of locating unexploded ordnance (UXO), as well as from an environmental toxicology standpoint.


Today, most of the materials used in munitions can be reused, recycled or destroyed at the end of munitions’ life. These processes should be performed in a way that the impact on health and
the environment should be minimized.


NATO by STANAG-4518.

The need for the application of design for disposal principles during the munitions development phase to obtain greener construction is obvious. These principles are standardized in NATO by STANAG-4518.

These principles were grouped under the name of “Design Safety Principles”:
a. Select materials that are not inherently toxic and can either be reused, recycled, or destroyed with minimum impact on health and the environment at the end of munitions’ life.
b. Select materials and design features that will minimize the adverse impact of credible service-life of environments and aging on demilitarization and disposal processes and by-products.
c. Select materials and design features that allow old operable stocks to be consumed in training.
d. Configure munitions for safe disassembling and ease of useful material recovery.
e. Configure munitions for ease of component and package reuse or recycling.
f. Design munitions to maximize service life.
g. Design munitions to permit significant life extension modifications and, consequently, reduce the need for demilitarisation and disposal.
h. Design for ease of alternative munitions applications with limited remanufacturing.


STANAG-4518 also gives information about demilitarisation and disposal process and disposal assessment process to be followed. The STANAG-4518 recommends the agreed countries to prepare a demilitarisation and disposal plan in the munitions development program which includes all necessary information related with demilitarisation and disposal of the munitions under development.


New Explosive Materials To Bring Nontoxic Ammunition

The toxicology level of the munitions components need to be examined and dangerous ones should be eliminated or reduced in quantity as much as possible. e. However this is not an easy task, the fact is that a substantial number of the munitions components are toxic, and replacements of most of the components do not exist. The number of poisonous components should be reduced in time by advances in science and technology.


When a gun trigger is pulled, a metal firing pin strikes a cup containing a primary explosive. The force from the firing pin deforms the cup, crushing the primary explosive and causing it to detonate. This explosion sets off a secondary explosive that burns and helps complete the rest of the firing sequence, accelerating the bullet out of the gun.


Experimental test shows the ability of silver salts to detonate just as well as commonly-used primary explosives. Because primary explosives are found in the cartridge of just about anything that fires a bullet, the Army has been searching for solutions for many years to develop lead-free versions of these explosives that satisfy environmental regulations associated with lead contamination. “The development of these materials provides a potential pathway toward lead-free technology,” said Jesse Sabatini, an Army researcher who led the project’s investigation of which molecules to use for these new materials.


What enables the materials to be lead-free is a chemical structure that has not been used in primary explosives before. One material is made of silver salts while the other material contains no metal at all – just the basic ingredients for an explosive. These ingredients include carbon, hydrogen, nitrogen and oxygen. “Toxicity-wise, silver is an improvement over lead, but it’s still a little toxic. So we also made a nonmetal material that does not have heavy metal toxicity associated with it. Metal is dead weight, energetically speaking, and doesn’t contribute much to an actual explosion,” Piercey said.


The chemical structure used in these materials makes them very dense, meaning that only a small amount of either material would be needed to create an explosion. Researchers at the Army Research Laboratory modeled these materials to get a sense of how explosive they would be. Piercey’s lab at the Purdue Energetics Research Center (PERC) made the materials and conducted experimental tests demonstrating that they work as primary explosives. According to the researchers’ calculations, the materials they created have a detonation performance similar to or higher than commonly-used primary explosives.


The CCDC-Armaments Center at Picatinny Arsenal, New Jersey, is interested in exploring these compounds for primary explosive-based applications for bullets and gun propellants. Purdue and Army researchers will continue to gather the data needed for determining which lead-based weapons systems these materials can replace. “At PERC, our theme is ‘molecules to munitions.’ Our labs can do everything from designing and testing molecules to formulating and manufacturing those molecules into a useful compound,” said Steve Beaudoin, director of PERC and a Purdue professor of chemical engineering. “Our partners can then take that useful compound and put it into a warhead, missile, rocket or whatever it needs to be.” A provisional patent has been filed for this technology (track code 2020-PIER-69143) through the Purdue Research Foundation Office of Technology Commercialization.


There are, however, potential environmental, occupational safety and health risks associated with these materials. Mitigating these risks throughout the life-cycle of these materials is costly and time-consuming. SERDP and ESTCP are the Department of Defense’s environmental research programs, harnessing the latest science and technology to improve DoD’s environmental performance, reduce costs, and enhance and sustain mission capabilities. The Programs respond to environmental technology requirements that are common to all of the military Services, complementing the Services’ research programs. SERDP and ESTCP promote partnerships and collaboration among academia, industry, the military Services, and other Federal agencies. They are independent programs managed from a joint office to coordinate the full spectrum of efforts, from basic and applied research to field demonstration and validation.


SERDP and ESTCP are investing in the development and demonstration of alternative materials and synthesis processes to reduce the environmental and occupational safety and health impacts of energetic materials and munitions while maintaining critical performance criteria.


US Army seeks environmentally friendlier ammunition

In a peer-reviewed paper published by Chemistry – A European Journal, researchers from the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory and Purdue University describe the synthesis of new environmentally friendly primary explosive materials. These green replacements could find application in small, medium and large caliber bullet and gun propellant ammunition.


What makes this research ground-breaking is that two unique backbones, known as heterocycles, that form the basis of energetic materials, were combined in a way never achieved before. Researchers said the result is very high energy, high-nitrogen content with a high gas generating ability, all desirable attributes for an explosive.


The Army has been searching for solutions for many years to develop lead-free primary explosives that satisfy environmental regulations associated with lead contamination.


Explosives are used not just for blowing stuff up. Inside of a bullet casing there is a small amount of primary explosive which is used to ignite the powder inside the cartridge. One of the materials that’s used in there right now is lead styphnate.

“Right now, whenever you are shooting, you’re going to be spreading lead into the air around you,” Piercey said. “Any use of lead is going to end up polluting the environment in small amounts. The more lead that you remove, the better it is for the environment.”
Piercey pointed to a study that found that people who had been shooting a lot had elevated lead levels.

The joint effort between the Army and Purdue highlights the laboratory’s Open Campus business model, which allows for collaboration between Army researchers, academia, industry and small business, both nationally and globally.


References and Resources also include:



About Rajesh Uppal

Check Also

Unlocking Sustainable Energy: AI Supercharges the Future of Energy Storage Systems

Introduction: In the ever-evolving landscape of technology, artificial intelligence (AI) has emerged as a catalyst …

error: Content is protected !!