The E2458 Protocols
ASTM Standard Details the Collection of Suspicious Powders
In December 2008, letters sent to more than 40 U.S. governors as well as to U.S. embassies and missions carried suspicious white powder.
Several years before, in October 2001, a New Jersey post office handled letters tainted with anthrax. That month marked the beginning of an ongoing wave of incidents making it necessary for agencies to respond to potential threats.
Not many people had the equipment or training to deal with a biological event before Sept. 11, 2001, recalls Jason Pastuch, an independent disaster preparedness consultant. Before that time, first responder, police, fire, hazardous materials, emergency management, county and state health departments, and other agencies had little, if any, experience with such incidents.
“I know as a first responder my department then had to place extra personnel on overtime to keep up, and the fear of the unknown was in everyone’s hearts,” says Pastuch, who was then a fire and hazardous materials professional in Cherry Hill, N.J.
Over time, procedures were developed, and the field experience and input of responders, public health groups, government representatives and other interested parties led to the publication in 2006 of ASTM E2458, Practices for Bulk Sample Collection and Swab Sample Collection of Visible Powders Suspected of Being Biological Agents from Nonporous Surfaces. The standard is the responsibility of Subcommittee E54.01 on CBRNE (chemical, biological, radiological, nuclear and explosive) Sensors and Detectors, part of Committee E54 on Homeland Security Applications.
“The methods in the standard were developed with input from federal partners and stakeholders who came together to try to determine, based on their experience, the best way to collect a powder. Important considerations in the development of the standard were that the sample collection procedure should promote the safety of personnel involved in the sample collection; reduce exposure risk; reduce variability associated with sample handling and analysis; and increase the reliability of sampling visible powders,” says Laurie Locascio, Ph.D., chief of the Biochemical Science Division at the National Institute of Standards and Technology, Gaithersburg, Md., who coordinated the development of the standard.
The E2458 Methods
ASTM E2458 organizes the process of collecting, containing and transporting small samples of unknown powders that are suspected of being hazardous biological agents; it details field protocols to be used when trained responders are confronted with an unknown, visible powdered substance. The purpose of these protocols is to allow various disciplines to speak the same language, work together in a unified fashion, and create a cohesive way of accomplishing the same objective without losing the integrity of a sample and providing evidence for the possible prosecution of the perpetrator.
E2458 is designed to minimize exposure risks to responders and citizens while ensuring that the samples have not been compromised by improper collection techniques. The standard also helps ensure chain-of-custody control, accounting for the integrity of a sample by tracking its handling and stops along the way from collection to final storage.
After an initial assessment to rule out an explosive, radiological or chemical hazard and determining that the powder is suspected to be a credible biological threat (any bacterium, virus or protein that could be used in biological warfare), emergency workers would follow the sample collection procedures outlined in E2458. This procedure involves collecting swab samples of a visible powder such as anthrax from a nonporous substance — the situation of most recent incidents, which have involved a suspicious white powder on an object such as a desktop. Many samples may need to be obtained to run them through a battery of tests called field screens; when field tests are complete other samples are collected and sent to a laboratory.
The standard describes a process with two stages. The first stage covers the bulk collection and packaging of a suspicious powder from a solid, nonporous surface and calls for using a dry swab and laminated card procedure followed by a sampling method using a pre-moistened swab. The second stage involves swab samples of residual powder from the surface to be collected for immediate on-site tests and biological screening.
As with any work in this area, safety practices need to be followed, including the use of proper personal protective equipment, and should be performed by teams of at least two people. One team member, who photographs the scene upon entry and during sample collection for documentation and training, is designated as the “clean” worker so that all sterile and uncontaminated equipment stays that way. The other team member, known as the “dirty” worker, handles the actual collection and cleanup.
The team uses such supplies as a drop cloth to create a clean work area, a sample transport container, which may be a bucket or large heavy duty plastic bag, and variously sized evidence bags and screw cap containers as well as labels and permanent markers. Add to this tamper-evident tape to ensure package integrity and paraffin wax sealing paper, which keeps jars and containers from leaking. In addition, a pre-mixed bleach solution, which kills most biological agents, should be on hand before entering a room with a potential threat — called the hot zone. The sampling and packaging and other equipment are all listed in E2458.
Once all the samples are collected the responder passes all bagged and tagged samples without breaking the chain of custody even through decontamination. Collected and packaged samples are transported to an approved laboratory within the U.S. Centers for Disease Control and Prevention Laboratory Response Network. There, further confirmatory and forensic tests are run to demonstrate definitively the presence or absence of a suspected substance or agent.
Refining the Standard
Responders and the public health community have now begun work to revise and refine the methods in E2458, and focus groups of these two communities have been formed and have met to discuss possible changes to the standard.
Bert Coursey, Ph.D., standards executive at the Department of Homeland Security, Washington, D.C., says that the standard addresses the problems with sampling white powders. For the revision, he adds, “We are actively encouraging all relevant federal agencies to participate in this revision to make sure it is consistent with their mission needs.”
Locascio says that those involved agree that a more nationally coordinated effort would help raise awareness of the standard, which is already used in training videos in New York state and elsewhere. “We all agree that a national training program is critical to the propagation and use of this and future standards,” she says. Such a program has been under discussion with several groups, including the Department of Homeland Security.
A revision to the standard may be ready for balloting this summer, but in the meantime, E2458 provides an effective process to address potentially hazardous visible powders. As Pastuch puts it, “We can basically get in and get out, and figure out if the threat is real or not.”
Jason Pastuch, who has 19 years of experience as a fire and hazardous materials responder, is now a disaster preparedness consultant based in the Tampa Bay, Fla., area.