Some passengers flying out of Baltimore-Washington International Airport will feel puffs of air scanning them for explosives as part of a test program that started yesterday.
A trace portal system, referred to as a "puffer machine," was set up at the security checkpoint for BWI's Concourse D, which has 47 gates, by the Transportation Security Administration, the federal agency in charge of airport security.
The agency is running similar tests in seven other airports and will start screening for explosive materials at six more airports by late spring.
Smiths Detection, a Pine Brook, N.J., technology company, supplied TSA with the explosives detector at BWI. It costs between $125,000 to $150,000.
The machine detects plastic and other nonmetallic explosive materials that can pass through in metal detector checkpoints.
"This is part of TSA's pledge to provide the traveling public the highest levels of security and customer service," TSA Chief of Staff James Fuller said yesterday.
The BWI airport program, which has an indefinite end date, also is expected to eliminate security pat-downs, said James Ports Jr., deputy secretary of the Maryland Transportation Department.
There have been numerous complaints nationwide, primarily from female passengers, that security pat-downs can be intrusive and over-used.
"Right now, we're going to go through the pilot program to find out how technically sound this is, if vibrations from the building disrupt the machine, if it's too much burden on passengers," Mr. Ports said.
"After we do that, then we decide which machine to go with," he said, noting that General Electric Co. also has an explosive substances tracing machine.
The General Electric machine has been used in three-week pilot programs for tracing explosive materials at Amtrak's New Carrollton and Union Station train stations.
During busier times at BWI airport, passengers will be picked to be screened by the trace-portal machine based on criteria the TSA would not disclose. At slower times, security officials will have all passengers pass through the machine and then through the metal detectors.
The Smiths Detection machine takes about 8 seconds to screen each passenger and can process about 420 passengers per hour, said Mark Laustra, vice president for Smiths Detection's transportation security civil business.
After emptying their pockets, passengers stand in the middle of the machine and wait a few seconds for puffs of air to be emitted. This releases particles on the passenger's body and clothing that are then drawn into the machine and analyzed.
Positive detection of particles or vapors can mean the passenger is carrying an explosive device or has come in recent contact with explosive substances.
Most of the innocuous particles are filtered out by the machine, Mr. Laustra said.
But there is a slim chance the machine will go off if a passenger is carrying residue after firing or handling a gun, he said.