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By Jack Maxwell
Jan 02, 2025
The members of the general public owe an enormous debt of gratitude to the dedicated individuals who work in fields like law enforcement, fire fighting, and highway maintenance. Their careers routinely place them in difficult, sometimes even dangerous, situations, yet they show up every day and do the job.
Members of ASTM International’s , including those who serve on the subcommittees on public safety equipment (E54.04) and response robots (E54.09), exhibit the same degree of dedication, albeit in a different form. Their focus is on developing test methods, product specifications, and other standards that help ensure the equipment public safety professionals rely on meets their operational requirements and provides a level of protection appropriate to the task at hand.
That equipment takes many forms. Whether it’s ballistic-resistant shields used by law enforcement personnel; protective headgear worn by roadway workers as cars speed by; or robots that operate in environments too hazardous for humans, the performance of these products can in some cases mean the difference between life and death. Here we examine some recently updated and approved standards that are intended to assist in the design, and facilitate the evaluation of, such products.
The subcommittee on public safety equipment covers a lot of ground. Among the types of gear impacted by its standards, one finds everything from body armor, to air-purifying respiratory protective smoke-escape devices, to protective gloves. Also within its purview, not surprisingly, are helmets.
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Four of E54's newest standards address the issue of helmet performance: the specification for nonballistic-resistant helmets specifically designed to be worn by law enforcement and corrections officers when maintaining order in violent situations (); the standard test method for nonballistic-resistant helmets worn by law enforcement and corrections (); the standard specification for ballistic-resistant helmets worn by U.S. public safety officers (); and the standard specification for protective helmets worn by pedestrian roadway workers (). In addition, the standard test method for ballistic resistant head protection () was approved in 2022.
There are multiple standards for this crucial piece of protective gear because the situations in which helmets are deployed can be very different. When you go from police officers in a gunfight to flagmen in construction zones on the interstate, clearly there is no “one size fits all” formula when it comes to creating standards that reflect the variety of helmet use cases.
Committee chair Casandra Robinson, an engineer with the National Urban Security Technology Laboratory (NUSTL, part of the U.S. Department of Homeland Security) says that it all depends on the specific nature of the threats faced by the individuals who wear them. “For example, public order police are more concerned with blunt impact, such as from a bat, a launched or hand-thrown projectile, or an impact on a curb if they’re pushed down during a riot. The same is true for corrections officers, because inmates do not have firearms but have many other improvised weapons. Law-enforcement officers, especially tactical officers, are more concerned with the impact of bullets from an armed suspect.”
This explains why separate standards are necessary for non-ballistic and ballistic helmets. “Blunt impact and ballistic impact are very different and require different tests,” says Robinson. E3343 (non-ballistic) includes test methods to assess protective performance against such hazards as impact/bump, projectiles (other than bullets), flame, and liquids. A helmet’s durability in terms of resistance to chemicals, temperature extremes, and weathering is also examined through the use of conditioning procedures.
On the other hand, E3368 (ballistic-resistant) focuses more on performance parameters like resistance to penetration (RTP) of shell, fasteners, and weak points; helmet shell ballistic limit (the velocity required for a projectile to penetrate a particular shell material at least half the time); and face-shield RTP and deformation. This standard also includes tests to evaluate non-ballistic performance in areas like impact attenuation and shell compression resistance.
These three standards strive to match the level of testing required to the needs of specific end users. Doing so helps ensure that helmets are not over-designed for the task at hand.
“Take a pedestrian roadway helmet,” says Brian Montgomery of the National Institute for Standards and Technology (NIST), who chairs the subcommittee on planning and coordination (E54.91). “You might be able to wear the non-ballistic helmet in these situations, but because of the way it’s tested, it may not be designed for what you need. We try to build that’s asking for it so that helmets meet their needs and are not over-engineered, overly heavy, or more expensive than they need to be.”
Another type of protective gear used by many law-enforcement agencies is the ballistic shield (also referred to as a tactical shield). These devices are designed to stop bullets and other projectiles and also provide protection against thrown and swung objects. They offer more full-body coverage than a helmet and body armor, at least from a front-facing orientation.
The standard test method for ballistic-resistant shields for law enforcement (E3141) and the specification for ballistic-resistant shields used by law enforcement officers (E3347) were approved in 2023 and 2024, respectively. Montgomery notes that they represent a significant improvement in the way this crucial piece of equipment is evaluated. Prior to their development and approval, a 1985 standard created by the National Institute of Justice (NIJ) to ascertain the ballistic resistance of materials used to fabricate protective products (NIJ 0108.01) was often referenced by shield manufacturers, procurement officials, and others in the industry.
The problem with this approach is that the NIJ standard only covers the materials that comprise the body of a shield, not the finished product – and shields used by SWAT teams and public order police are complex constructions. It’s no surprise that the main body and transparent viewport are made of ballistic-resistant materials, but there are fasteners, interfaces, joints, seams, and edging. In addition, appliques are sometimes attached to the shield to add another layer of protection in particularly vulnerable areas.
“Manufacturers would use NIJ 0108.01, which is OK for the ballistic material, but things like handles, fasteners, seams, and interfaces between the shield and the viewport would not be addressed in a general ballistic material standard.” Montgomery says.
Growing awareness of this issue spurred E54 to initiate a collaborative process involving dozens of stakeholders, including shield manufacturers; suppliers; federal, state, and local law-enforcement end users; ballistic testing and certification experts; researchers; federal ballistic-protection experts; and standards professionals. The work of gathering input, developing test methods and specifications, and achieving stakeholder consensus was facilitated by ASTM’s proven standards-development process and driven by the members of E54.04.
E3141 and E3347 are the results of this effort. The former spells out detailed procedures to assess every element of the shield and requires a minimum number of shots to the shield body, viewport, fasteners, edges, joints, weak points, and appliques. The latter specifies pre-conditioning and testing requirements, ballistic performance levels, and performance metrics the shield must achieve.
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As the basis for a new and more comprehensive way to evaluate ballistic shield performance, E3141 and E3347 will serve as the technical foundation of a new ASTM verification program. The helmet standards referenced earlier will play a similar role in verification programs for the different categories of protective headgear.
The Safety Equipment Institute (SEI), an ASTM affiliate, will manage the program, performing independent, third-party verification, listing verified products online, authorizing manufacturers to place the ASTM-verified mark on their products, and managing the process of annual testing to assess ongoing compliance with the standards. Verification is a relatively new concept that is intended to serve as a less costly alternative to full-blown certification programs, which in addition to pre- and post-market testing components, require additional steps that add to the cost and inconvenience for manufacturers.
“There’s a spectrum of conformity assessment, and verification programs are toward the higher end of that spectrum but not quite to the level of certification, which is the highest,” Montgomery explains. “Not requiring manufacturing facility and supplier management system audit requirements may lower the cost while still giving end users a level of confidence that a product does meet the standard.”
Although there are currently no federal regulations that mandate verification, the ValuePoint program of the National Association of State Procurement Officers (NASPO) intends to require that ballistic-resistant shields be ASTM-verified to be eligible for purchase. In addition, the manufacturers that assisted in the development of E3343 and E3368 have agreed to submit their products to the ASTM verification program.
The ballistic shield and helmet programs join a growing roster of ASTM verification programs related to law enforcement and homeland security. Products covered include ballistic-resistant body armor accessories and hand-worn, hand-held, and walk-through metal detectors. There is also a verification program for reflective insulation.
The focus thus far has been on protective gear for various types of law-enforcement personnel that is either worn (helmets) or wielded (shields). But there’s another equipment category that helps these individuals stay safer when responding to massive catastrophes like earthquakes, wildfires, and even nuclear meltdowns: response robots.
Also referred to as rescue robots and disaster or emergency-response robots, these machines come in many configurations and are able to walk, crawl, fly, and navigate above and below water. Earlier versions of this technology have been in use for decades, including a camera-equipped crawler that searched debris fields after 9/11 and Hurricane Katrina; firefighting robots with hoses, heat shields, and treads; and robotic lifeguards that can speed across the water to serve as flotation devices for struggling swimmers.
The subcommittee on response robots (E54.09) has been creating test methods and standard practices to help stakeholders evaluate the performance of these valuable tools for nearly 15 years. In the class of ground robots alone there are no less than 23 approved standards, with another nine out for balloting at the time of this writing and eight at the prototype stage at which apparatuses, procedures, and performance metrics are tested prior to development of draft standards.
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Subcommittee chair Adam Jacoff, project leader for emergency response robots at NIST, points out that the ground robot standards operate in suites, with complementary tests covering areas such as logistics, sensing, radio communications, mobility, dexterity, and situational awareness. “No single test is more impactful than any other, although several of the mobility tests literally changed the concept of robot mobility, inspiring development of a whole new class of mobile robots with body tracks and four independent flippers.”
Interestingly, competition has proven to be a valuable approach to advancing the capabilities of response robots and crafting standardized test methods that support their evolutionary development. “Our RoboCupRescue event last summer in the Netherlands conducted 700-plus trials using three different scales of tests,” Jacoff says. “So we get to see if the test apparatuses are inspiring successful reactions from the robotics research community. If so, the robots are on the right track toward potential commercialization. If not, we need to determine why not.”
An example of how the process works is the standard test method for evaluating response robot mobility using symmetrical stepfield terrains (E2828). Terrains are fabricated and repeatable obstacle courses often made of wooden shipping pallets. Jacoff notes that E2828, first balloted around 2008 and updated several times since then, reflects modifications to the terrain that improved its utility.
“The symmetric stepfields started as “random” configurations of certain terrain elements – pallets of flat, transverse hills, and diagonal hills made from the vertical 4x4 posts – that followed a randomized script of sorts to limit the complexity,” he explains. “The random version was much closer to representative of a real rubble pile situation than the symmetric version that ended up as the standard test method.
“However,” Jacoff continues, “the random terrain elements would invariably thwart robots when a single post was inconveniently placed. And that post may not be in the same location in subsequent trials, so the terrain was not turning out to be ‘repeatable’ from trial to trial, or even from lap to lap. That’s a problem with the test method.” Switching to a geometric topology that included the same terrain elements but in a symmetrical configuration that would be repeatable every lap resulted in a better standard test method.
Another improvement to the stepfield terrain is on the way: a more purchasable and reproducible version made from plastic crates rather than wood pallets. Jacoff points out that the original version is expensive, time-consuming to fabricate, and difficult to move – issues that make it difficult for researchers, manufacturers, or responders to replicate. Plastic crates, on the other hand, are rather ubiquitous and similarly sized around the world.
Asked to highlight other examples of significant response robot standards, Jacoff looked to the sky – and the future. “The most impactful standard test method we’ve ever developed will certainly be the newest suite of tests for aerial drones,” he says. A series of 15 related and complementary tests have been developed to evaluate performance in open, obstructed, and confined environments. The first five tests went to ballot in October, but they’re already being used worldwide to evaluate drone pilot proficiency as part of the test method validation process.●
Jack Maxwell is a freelance writer based in Westmont, NJ.
January / February 2025
