ABERDEEN PROVING GROUND, Md. -- The U.S. Army Edgewood Chemical Biological Center provided the Maryland State Police with a test of their Millennium gas masks Aug. 30.

Twelve men from the Special Tactical Assault Team Element completed multiple rounds of testing at ECBC's Protection Factor Testing Facility in order to properly fit equipment that would be used in the event of a chemical biological attack.

"The big thing with us, especially with today's world and the possibility of terrorist attacks, there are more parallels and we're getting tasked with more military-type missions that we have to be prepared for," said 1st Sgt. Keith Runk, commander of the STATE unit.

According to Runk, his squad would be responsible if a chemical, biological, radiological, nuclear and explosive threat turned into a reality at a local level within the United States. The paramilitary responsibility has spurred a more collaborative effort between the Maryland State Police and ECBC, and resulted in an annual pro bono mask fit testing that ensures the gear passes military standards.

"Who better to help us than the military? They're seeing it on a daily basis. They're training for it. They're preparing for it, and all of our equipment, at least from the SWAT perspective, is held to the same [military specification] standards," said Runk.

The Protection Factor Testing Facility is designed to quantitatively evaluate chemical protective capabilities of respirator systems such as masks and protective clothing. During each round of protection factor testing inside a corn oil chamber, the STATE unit completed 10 one-minute exercises designed to stress the masks ability to seal to the subject's face. These exercises included normal breathing, deep breathing, sighting the rifle, reaching for the floor and ceiling, facial expressions and moving the head in different directions.

"With the corn oil chamber we measure the ratio of the chamber concentration versus whatever concentration gets inside the mask, resulting in a PF number. So if the mask is properly fitted and working correctly no aerosol gets inside the mask and a large PF number is generated," explained Steve Yurechko, protection factor team leader at ECBC.

"Protection factor is the pass/fail criteria for a mask. Each mask has a minimum PF…it should meet when somebody wears it correctly. That's what we verify here," Yurechko added.

To simulate exposure to chemical or biological agents, the test subjects were exposed to the corn oil aerosol, which has a mass mean particle size that replicates various agents like anthrax. The air inside the gas mask is sampled through a silicon tube that connects from the mask to laser photometers that graphically display the results in real-time on a computer monitor inside the control room. A drop in the PF level indicates there is a problem with the mask such as a leak or a fitting issue.

Yurechko discovered two faulty masks throughout the testing. One mask was failing throughout the entire test due to missing valves noted by the test subject; however after they were reinstalled correctly, the mask began working properly. A second mask had failed the overall PF test and after inspecting the equipment, Yurechko discovered a deformed gasket between the filter and the mask itself. Though he could not replace the gasket, the technician was able to tighten the filter enough to alleviate the problem and pass the test. It was recommended, however, that the faulty gasket or the mask itself be replaced.

"Once we figure out what's physically wrong with a mask and correct it, we usually don't see the problem too much anymore and it becomes a matter of correctly sizing and fitting the mask to the person's face. The most important things when doing this is to make sure the person is wearing the right size mask, that they don the mask correctly, and they're clean-shaven," said Yurechko.