Near Real-Time monitoring using Miniature Continuous Air Monitoring Systems (MINICAMS) and Depot Area Air Monitoring System (DAAMS) will be conducted in areas of the Pueblo Chemical Agent-Destruction Pilot Plant (PCAPP) where there is reasonable potential for mustard agent contamination. A key component to the chemical agent monitoring program is Interference Testing.

“In the 20-plus year history of chemical demilitarization programs, we have learned that products used to maintain the facility, such as oils, greases, paints and caulks, can degrade the MINICAMS and DAAMS monitoring capabilities,” said Brian Ramdwar, operations branch manager, PCAPP.

The degradation presents itself as a false-positive or a false-negative alarm. A false positive alarm is when the MINICAMS alarms even though chemical agent is not present. A false-negative alarm occurs when the monitoring system is blinded from detecting chemical agent, said Ramdwar.

“We have learned from a human performance standpoint, numerous false-positive alarms results in loss of confidence in the monitoring system by the workforce,” Ramdwar said.

To reduce the likelihood of false-positive or false-negative alarms, the PCAPP Laboratory has implemented an Interference Testing program whereby all products used in the facility undergo analysis by the MINICAMS and DAAMS prior to use.

“We look at the quantitative results, and can identify if it is a normal result, a positive interference or a negative interference,” said Mechelle Cass-Burrell, gas chromatography/flame photometric detector/mass selective detector operator, PCAPP.

Products known to cause a false alarm are restricted from use in the plant. However, occasionally a product that is known to cause interference must be used. In those cases, a rigorous process and plan is developed. Typical contingencies can include suspending chemical operations, upgrading Personnel Protective Equipment and increasing ventilation, Ramdwar said.

The PCAPP Laboratory has published a list of all products that have been tested and the results are available for personnel to view and assess prior to performing work. To date, nearly 600 products have been tested.

“If, at the laboratory, we can help disseminate information on how a product will interfere with the monitoring equipment, better, instructive decisions will be made,” Cass-Burrell said.