JOINT BASE LEWIS-MCCHORD, Wash. - It's not every day that you see highly trained infantryman running around in a circles, yelling and screaming with tears in their eyes, but it was surely understandable during this particular training event.

Soldiers assigned to 4th Battalion, 9th Infantry Regiment, 4th Stryker Brigade Combat Team, 2nd Infantry Division conducted their yearly M40 Field Protective Mask confidence exercise June 1 and 2 at the Nuclear, Biological and Chemical Range 1, here.

Ensuring that soldiers can confidently and quickly put on their gas masks is a major part of a soldier's readiness.

"Confidence in your equipment will mean a great deal if you need to use it in a real life situation," said Sgt. Anastasia Maynich, the chemical, biological, radiological and nuclear non-commissioned officer and instructor assigned to 472nd Signal Company. "We are showing these guys how important it is being prepared for an event like this."

Even though every service member undergoes this training when they first enter the military, having to re-enter the chamber and be exposed to a painful irritant like CS gas is not exactly the type of training that soldiers eagerly anticipate.

"It is one of the most hated training [events] in the Army," chuckled Maynich. "Well, maybe not, but when soldiers come to see us for the training, they always leave certified and in tears."

Even though the M40 Field Protective Mask confidence exercise is an annual training event, it took a great deal of planning and coordinating in order to make it happen.

"I have been planning this event for three months so that every Manchu soldier would have the opportunity for [chemical, biological, radiological, nuclear] training", said 1st Lt. Hyun Yi, the battalion CBRN officer in charge. "It is very important to me and my commander that we accomplish this training."

As part of the exercise training, soldiers were familiarized with the NBC Reconnaissance Vehicle and the Joint Chemical Agent Detector. They then put their readiness to the test as they raced the clock to don their gas masks within the nine second standard.

"I haven't done this in a while, so it is very good to get this refresher," said Spc. Thomas Butzfiscina, as he adjusted his gas mask carrier straps around his waist. "My squad actually was competing to see who would be the quickest to put on their pro mask."

He added that even though he didn't win, he felt it was good training because you never know when you're going to need to use it.

Another part of the training was to identify the various levels of Mission Oriented Protective Posture and the different situations in which they are used.

But before any of the soldiers could be certified, they had to enter the CS gas chamber for their final test where the stinging effects from the CS gas could be felt 50 meters in any direction of the building.

"I love it when the soldiers are lined up to go into the CS gas chamber, and just the looks in their eyes lets me know that they are taking the training seriously," said Maynich.

Once the soldier walked inside, the chamber's doors were shut, sealing the occupants in darkness and leaving their fate in the hands of the instructors.

"We had the soldiers perform side-straddle hops to build their heart rate a little," said Maynich. "Then we asked every soldier to open their mask and say their names, rank and today's date."

She explained that the purpose behind the soldiers doing physical exercise was to give the effect of a stressful environment.

"After they told us all that stuff, they had to put back on their masks and do what they call ‘seal and clear,'" said Maynich. "That's where they get all the gas out of the masks"

After the soldiers completed this task there was only one thing left between them and the fresh air outside.

"In order to leave the chamber they had to completely take off their mask, exposing their entire face to the CS gas," she said.

Initially, the infantryman in the chamber held their poise, however slowly but surely, the effects of the gas became apparent.

"I was choking and coughing," said Sgt. Timothy Gatlin, an infantryman assigned to the unit. "I have done this before, but I was so ready to get out that chamber."

Scrambling for the door, the soldiers hastily moved outside to find relief from the agony of the CS gas.

"I couldn't see, and it was like everything was burning," explained Gatlin. "I walked about flapping my arms, trying to air out some of the CS [gas]."

The effects of the gas most lasted no more than a few minutes, but for the soldiers, it left a lasting impression and the knowledge that in a chemical environment they can depend on their protective gear.

"We are war fighters," exclaimed Yi. "We train for the worst case scenario, and so the better we train, the better we are going to fight."