Researchers at the U.S. Army Soldier and Biological Chemical Command
in Natick, Mass., are working on new technologies that, in the distant
future, could provide an alternative to the current carbon-based
chemical, biological protective suit, the JSLIST (Joint Service
Lightweight Integrated Suit Technology).
All military services have used JSLIST since 1997. It replaced
the old battledress overgarment (BDO).
Natick project engineer George Costas said that one of the most
promising technologies for future protective garments is the selectively
JSLIST is today’s suit of choice by all the military services,
Costas explained. “For the next 10 years, they will stay with
the design, and all the changes made will be in the fabric.”
The JSLIST overgarment is a universal, lightweight, two-piece, front-opening
suit that can be worn as an overgarment or as a primary uniform
over underwear. It has an integral hood, bellows-type sockets, high-waist
trousers, adjustable suspenders, adjustable waistband and a waist-length
jacket that enhances system comfort, improves system acceptance
and maximizes compatibility with the individual user equipment.
Apart from the integral hood, on the waist-long coat, a flap fastened
with Velcro covers the zipper. The sleeves also have Velcro wrist-
closure adjustment tabs, and the left sleeve has an outside expandable
pocket with flap.
The JSLIST liner consists of a non-woven front, laminated to activate
carbon spheres and bonded to a knitted back that absorbs chemical
agents. Previously, the BDO liner consisted of charcoal-impregnated
polyurethane foam and nylon tricot laminate. The BDO foam deteriorated
as the soldiers rubbed against it, and that could become messy.
The durability of the JSLIST is 45 days, compared to 22 days for
the BDO. While the old suit was not washable, the JSLIST can be
washed six times. Costas said the suit not only feels a lot cooler,
but it is one pound lighter than the BDO, and when packaged, it
is 60 percent less bulky.
But Gene Wilusz, a developer of the selective permeable membrane,
explained that a suit that uses the membrane system, instead of
charcoal, is actually half the weight of the current JSLIST.
“Quite a lot of charcoal is needed to provide the necessary
protection and that results in a suit that is heavier and bulkier
than ideal,” said Wilusz. “Activated charcoal has worked
very well so far as a universal absorbent, but we are trying to
reduce the dependence on charcoal. The membrane essentially replaces
charcoal as a protective material.”
Wilusz noted that charcoal can absorb other chemicals in the area,
such as exhaust fumes, smoke and other things that soldiers can
come in contact with on the battlefield. “They are absorbed
just like the [chemical and biological] agents can be absorbed in
the charcoal. That is not really an issue with the membrane,”
He explained that the membrane is used as part of a system that
has outer-shell material and inner lining made out of a traditional
The membrane acts as a barrier to chemicals and biological agents,
while still allowing the movement of vapor moisture. Thus, Wilusz
said, “there will be some measure of release from heat stress,
through an evaporative cooling mechanism.
“Some of the sweat that occurs just by wearing additional
clothing will be able to pass through the suit to the outside, right
through the membrane,” he added.
“The carbon-based suits only last in the field for 45 days,
without being contaminated because the carbon itself gets poisoned,”
said Elizabeth McCoy, chemical defense coordinator at Natick. However,
she said, the membrane suits can last as long as the JSLIST or longer.
“You don’t have to worry about the carbon being poisoned,
and you can wear it out as long as the membrane is still viable,”
“Membrane technology protects against everything, it just
doesn’t let anything go through, but it let’s moisture
vapor go out, so that you can have the cooling,” McCoy said.
“One of the big challenges is where to close the suit up,”
said Costas. “Close it around the head to interface with the
helmet, close it around the legs to interface with the boots, close
it around the wrists to interface with the gloves.”
But researchers at Natick also are looking at how to increase protection
through the closure systems of the suit.
Wilusz explained that they were testing rubber seals at the sleeve
and neck area. “The rubber parts meet together to form a seal,”
he said. “O-rings are very tight seals, so they give a superior
seal,” added Costas.
Another way to increase the protection of the suits is to make
them one-piece. “The coverall has an advantage over the two-piece
suit,” said Wilusz. But he said the one-piece may also be
more difficult to fit everyone properly, and many soldiers prefer
the two-piece. “We may have to end up with both,” said
“When we have prototypes and have them evaluated we get a
lot of feedback about what they like and what they don’t like,”
Wilusz said. “It’s a back-and-forth process.”
So far, some Army and Marine Corps users tried out the new membrane
suits in short-term exercises, Wilusz said. “The garments
have done very well, but they need to be tested in much larger scale
The two contractors working on membrane technology are W.L. Gore
& Assoc., in Elkton, Md., and Texplorer, based in Germany. So
far, W.L. Gore has spent about $6 million to produce the membrane
technology, according to Natick program manager Quoc Truong. Natick
provided technical guidance and testing assistance. Texplorer, which
produces the Spiratec membrane technology, has a 50 percent co-share
agreement with Natick to produce 400 garments, which will then be
tested in the necessary operating environments.
Since 1997, the Army has spent $500,000 a year to develop the membrane
technology. Natick also will receive $1.25 million from the Memorial
lnstitute for the Prevention of Terrorism.
Tex-Shield, in Mount Laurel, N.J., is the sole fabric supplier
and is a subcontractor to the four manufacturers of the JSLIST suit.
“If that fabric [membrane technology] gets to the point where
it will stand up to all the rigors of the battlefield with soldiers
crawling on the ground, jumping out of vehicles, and it is durable
and meets all the requirements, we may take the [JSLIST] design
and use the membrane technology,” said Costas.
“If the past is any guide,” he said, “the BDO
was around for 20 years, so the JSLIST will be around for 20 years.
It’s quite a new suit.”
Costas said that, in his opinion, one of the most important features
of the JSLIST is a hood that is directly attached to the suit coat.
“It gives a lot more protection, because it eliminates leakage
around the neck area,” he said.
The membrane technology, Wilusz said, is a candidate for the joint
protective aircrew ensemble (JPACE). If the membrane technology
gets accepted in that program, “it will also be a candidate
for the next generation JSLIST garments,” said Wilusz.
“That’s futuristic, it’s way out,” said
The chemical and biological protection gear for Navy and Air Force
comes with the M-40 mask. Michael T. Benham, a representative of
the Army’s program office for NBC Defense, said that the JSGPM
mask will replace the M-40. Because it is more close-fitting to
the face, the visibility in the new mask is much higher, said Benham.
He also said that it would be lighter with smaller filters and have
simplified maintenance requirements. “It would be less expensive
and less of a logistics burden,” Benham added. An M-40 mask
costs approximately $300. The new mask will go into production in
Another development is the Helmet-Outvision 22, which is just a
concept, “but it is going to give the same capability as a
helmet and also provide chemical protection,” Benham said.