New Insensitive Munitions may pose lingering toxic threat

Hanna Homestead is the Director of the Climate and Militarism Program at the Center for International Policy.

In February, the Washington Post reported the story of Hind Rajab, a six year old Palestinian child who spent the last three hours of her life trapped in a car with seven dead members of her family, pleading for help. The family was following evacuation orders from the Israeli military when their car was targeted. An ambulance was then dispatched to rescue Hind with permission from Israeli authorities. Despite being clearly marked as a medical transport vehicle, radioing its location, and following the approved route provided by the Israeli military, the paramedics came under heavy fire. Further investigation by the Post found the destruction of the ambulance was “consistent with the use of a round fired by Israeli tanks, according to six munitions experts.” The fragment of a US-made 120mm tank-fired round was reportedly found near the charred vehicle, which had a visible foot-wide hole consistent with the exit of a tank projectile.

Given nearly two weeks had elapsed before it was safe to investigate the scene, experts could not definitively verify the fragment was directly involved in the strike. However, satellite imagery proved that Israeli tanks capable of firing 120mm rounds were in the area when the attack on the ambulance occurred. In December, the Biden Administration bypassed Congress – a highly controversial move – to approve the transfer of nearly 14,000 anti-tank 120mm MPAT rounds to Israel despite evidence of ongoing, indiscriminate, and systematic targeting of civilians.

The transfer of US-made explosive weapons, including 120mm MPAT rounds, 155mm artillery shells, and Mark-84 unguided bombs are playing a central role in the Israeli government’s genocidal efforts to “make Gaza uninhabitable,” resulting in Hind’s death as well as more than 30,000 civilians over the last six months. Even spent, the remains of the round poses a toxic risk. Explosive weapons contain chemicals and heavy metals that contaminate water and soil for generations, fueling displacement and food and economic insecurity that threatens regional and geopolitical stability. Both the detonation and production of explosive weapons contribute to severe and long-lasting-environmental contamination, resulting in direct deaths and civilian harm that continues long after the explosions occur. Recent Pentagon efforts to make munitions “safer” for military personnel not only downplay, but threaten to exacerbate these widespread toxic legacies.

Munitions, made in America

Within the US, the production of explosive weapons has resulted in massive amounts of pollution and ecological destruction. There are currently more than 40,000 military sites across US states and territories that are contaminated with toxic military waste and legacy explosives, creating significant and cascading public health challenges. The DoD has already spent more than $40 billion attempting to clean them up, and recent estimates by the Government Accountability Office found the DoD faces at least $91 billion in future environmental liability costs. Historically-marginalized populations are particularly at risk of harm from toxic contamination. Superfund sites are more likely to exist in low-income areas, and are correlated with lower life expectancy in the surrounding communities.

The US is currently in the process of ramping up explosive munitions production to continue arms transfers and to replenish depleted domestic weapons stockpiles after significant amounts of defense equipment were transferred to Ukraine and Israel over the last two years. Not only are production rates increasing significantly, but the DoD is transitioning from producing larger-caliber munitions containing legacy energetic materials (explosives, nominally TNT and RDX) to those made with “insensitive” high explosives (IHE), also referred to as insensitive munitions (IM). Insensitive munitions are designed to be less reactive to stimuli and therefore safer to transport and store, an understandable goal when stockpiling explosives. This function is perceived to be both necessary and advantageous by the DoD and members of Congress interested in producing a larger war reserve to avoid future stockpile depletion.

In December 2023, defense giant BAE Systems was awarded a DoD contract worth $8.8 billion to produce the insensitive high explosive IMX-101 to be used as a “safe and effective” replacement for TNT in new artillery rounds. IMX-101 is the main explosive fill used in new 155mm M795 projectile production – currently one of the most highly sought-after munitions – replacing the legacy 155mm M107 projectile. While the development of IMX-101 has been in the pipeline for decades, the increased demand for ammunition from Ukraine and Israel, as well as competition to modernize vis a vis China, has spurred Congress to “expedite” testing and oversight to hasten the production of weapons made with IHE.

While offering functional advantages, the full impact of insensitive munitions on human and ecological health is not yet known, and what data is available raises concerns. Experts infer that some of the chemical compositions of IHE are likely to differ considerably from legacy explosives in their properties, and “therefore, also in their effect and behavior in the environment.” Yet, the DoD maintains there is limited information in the literature regarding human toxicity and adverse health effects due to exposure to insensitive explosives, including IMX-101. It is also unclear how environmental assessments and data on IHE that do exist are evaluated or incorporated into ongoing IM manufacturing, training, and operational planning. While IM weapons have been described as a way the military can “have [its] cake and eat it, too,” a closer look at the development of the 155mm M795 projectile made with IMX-101 raises a number of concerns.

IMX-101 appeared on the scene in 2010, after being named one of “The 50 Best Inventions of 2010” by TIME Magazine for its promise to replace TNT as a “less dangerous explosive.” Early testing of IMX-101 weapons was fast-tracked from what’s typically a five-year test period to two, and did not include comprehensive assessments of the ecological toxicology of the compound or its residues resulting from its production or operational use. Qualification testing of 155mm projectiles made with IMX-101 generally focused on the weapon’s performance, showcasing how IM projectiles can withstand various catalysts while maintaining lethality when deployed as intended. The results were published along with DoD assurances that “IMX-101 and its ingredients were found to be less toxic than RDX and the IMX-101 detonation products were calculated to be benign.” However, research conducted at the DoD’s Picatinny Arsenal used to certify the low-risk profile of IMX-101 shells has since been retracted due to inaccuracies and inconsistencies in the data. The original DoD 2009 study (no longer publicly available) indicated over 99.99% of all energetic material was destroyed during detonation, signifying the munition did not pose a contamination risk.

Eight years later, subsequent field experiments funded by the DoD Environmental Restoration Program demonstrated that in fact, over 30% of some energetic compounds remain after detonation – meaning the IM shell poses a significantly higher risk of environmental contamination than originally reported. Further DoD research has shown IM munitions deposit more residues than legacy explosives. These residues can persist in the environment for long periods of time following detonation, as research has indicated “the half-life of munition particles was estimated to range between 66 and 228 years for IMX-101.” A revised 2019 toxicology assessment of IMX-101 released by the US Army Public Health Center also points to a number of primary adverse health and reproductive effects on animal and plant life following exposure to IMX-101 compounds and recommends further testing, noting the DoD’s lack of comprehensive and long-term studies on IMX’s human and ecological toxicity. Numerous researchers have since published findings on the toxic effects of IMX-101 and its degraded residues – including their potential to have greater contamination risks than TNT or RDX.

Additionally, while research shows the “dud” rates for IM munitions do not differ significantly from legacy explosives, the DoD’s Defense Systems Analysis Center has indicated the disposal of unexploded ordnance (UXO) made with IHE, like IMX-101, may require up to 400% more explosives than legacy munitions given their “insensitive” characteristic. This carries significant implications for post-conflict remediation of unexploded ordnance and pollution of military testing sites. UXO must be removed and detonated, otherwise they degrade and leak poison indefinitely, irreversibly contaminating soil and groundwater.

The challenge of UXO removal is of particular concern in Gaza due Israel’s excessive bombing in urban settings, where munitions experts say there is a higher rate of failed detonation. The use of IMX-101 munitions, including the thousands of 155mm M795 projectiles the US is currently supplying to Israel, has the potential to significantly increase the cost of environmental remediation which is already expected to require tens of billions of dollars and take many years to complete. Environmental justice, including the remediation of ecological damage caused by Israel’s heavy bombardment and ongoing siege, will be critical to the safe return of displaced Palestinians to Gaza and to lasting regional peace.

Despite mounting evidence of the need for greater oversight over insensitive munitions modernization, Congress has continued to loosen the reins. The FY 2024 NDAA passed in December established a new Joint Energetics Transition Office within the DoD to “expedite testing, evaluation, and acquisition” of “new” energetic materials. Military personnel in charge of procurement report they have “a lot of freedom to maneuver now” due to the new programs Congress has authorized.

Aftermathematics

The expedited approval and production of new insensitive munitions without adequate understanding, transparency, or planning in regard to their toxicity or long-term contamination risks comes as research is revealing the extensive impact of legacy RDX and TNT contamination on human health and the environment. For decades, the DoD fought against environmental oversight, claiming “environmental cleanups would come at the expense of the safety of U.S. forces in Iraq and Afghanistan.”

According to ProPublica reporting, when the US went to war in Iraq in 2003, top Pentagon officials led by Defense Secretary Donald Rumsfeld attempted to shield the DoD from nearly all environmental oversight measures to preserve “readiness.” Though these efforts failed, throughout the following years the Pentagon sought to undermine accountability for pollution caused by weapons production, including funding and publishing studies downplaying the health and ecological risks of producing legacy explosives. Today’s focus on weapon’s modernization at the expense of adequate environmental testing sounds eerily familiar. In addition to expediting IMX-101 production, the FY2024 NDAA included authorization for the Pentagon to test warheads and propellants using the insensitive energetic material CL20, despite a 2007 DoD study indicating CL-20 residues likely pose a significant toxic ecological risk.

Efforts to clean up contamination caused by legacy weapon’s production and testing are currently underway within the United States, thanks to the persistent organizing of frontline communities. The Environmental Protection Agency (EPA) recently announced an additional $1 billion in new Superfund program funding, which includes military sites. Other types of military-related pollution such as radiation exposure due to nuclear weapons development and testing and PFAS contamination are also being recognized as serious public health concerns. Veterans who were exposed to toxic substances from burn pits, which include UXO disposal, are finally being provided with health benefits after decades of denied claims. While much more still needs to be done domestically, there are currently no legal requirements to address toxic legacies of war abroad caused by US weapons that are deployed directly by US troops or transferred abroad. Americans rarely have insights into the devastating and destabilizing long-term effects these weapons have on foreign populations.

The DoD procurement decisions being made today will have long-term, global impacts. Congress must realistically assess the risks of IM procurement and deployment in order to make an accurate judgment on if the marginal tactical advantages outweigh the human, moral, geopolitical, and financial costs of ecological destruction. Further, Congress should take proactive steps to ensure the comprehensive health effects are accurately assessed and publicly disclosed. The production of IM munitions must not continue the destructive history of legacy explosive contaminants – which will impact affected communities in the US and internationally for decades, and potentially permanently. Congressional oversight is especially important now as the Supreme Court is likely to overturn Chevron deference this year, limiting the EPA’s ability to regulate and mitigate pollution harms.

The US also has a terrible track record in regard to remediating environmental war contamination.

Given that available data show that insensitive munitions may be more difficult, expensive, and environmentally harmful to dispose of (potentially requiring 400% more explosives to detonate), Congress should ensure this information is incorporated and budgeted for in post-conflict remediation planning. Considering the US Army’s poor history with UXO disposal via burn pits in the past, Congress should ensure that the Pentagon plans for IMX UXOs before deployment and adopts principles for assisting victims of toxic remnants of war into their operating policies. This matters immediately, from the first responders making perilous rescue runs the moment the guns are silenced. And it matters long term, as bomb disposal crews clean up and people return to make a life out of the rubble.

For too long, the true human and ecological costs of war have been excluded from foreign policy discourse. Weapons are ultimately made for one purpose: to kill. “Insensitive” munitions are no different; their use inevitably contributes to the destruction of each other’s children, our communities, and the biodiversity of our earth on which all life depends. The toxic ecological effects of these weapons must not be regarded as externalities or secondary to their battlefield functionality; environmental contamination negatively impacts conditions for long-term peace and global security and should be included in a realistic accounting of the costs of war. Ultimately, the best way to avoid these horrors – from mass death to environmental degradation to unexploded ordnance – is for policymakers to abide by and uphold human rights, and commit to resolving political disputes through diplomatic means.