Chemical Engineering March 2011 - 62

Environmental Manager
of a worker being exposed to potentially
harmful chemicals increases.
Conversely, overprotecting a worker
with unnecessary clothing can be burdensome
and result in heat stress, reduced
field of vision, restricted mobility
and increased physical exertion for
the wearer, as well as possibly higher
purchasing costs for the employer.
Every work situation is unique,
and the ISO 16602 Standard does not
consider all specific hazards that may
be present in the work environment.
Safety and occupational health professionals
need to consider hazards that
are specific to their work conditions
and then look to ISO 16602 to find the
minimum requirements for chemical
protective garments for that type of
situation. ISO 16602 focuses exclusively
on typical chemical hazards
and protective clothing requirements
for such hazards so the work situation
may also require additional forms of
PPE, such as footwear, gloves, face protection,
fall protection and respirators.
When evaluating protective clothing
performance under ISO 16602, gloves,
footwear and respirators must be included
in the whole-garment ensemble
testing. It is important to validate
that any additional PPE components
will work properly with the chemical
protective clothing selected for use.
Types of clothing
The ISO 16602 standard is based upon
a series of types and classes. ISO 16602
designates minimum performance levels
for six types of chemical hazards.
The type is the overarching system,
with chemical protective clothing fitting
into one of the six different types.
The garment type designation is based
upon the physical state of the hazard,
for example vapors, liquids, aerosols
or particles (Figure 1).
When setting the requirements for
each type in ISO 16602, the entire garment
is tested as well as the individual
components. During the whole-garment
tests, a " human subject " wears the test
garment and accompanying PPE, such
as gloves, boots and respirator. The
human subject is exposed to non-hazardous
test chemicals while in an enclosed
chamber performing a series of
movements meant to simulate actual
work activities. This whole-garment
testing is used to validate the barrier
performance of the entire ensemble
against a specific type of chemical
threat (gas, liquid or particle). Wholegarment
testing is conducted for each
ISO 16602 type, and the exposure conditions
for the tests vary according to
the hazard defined by that type. Note
again that the test chemicals are nonhazardous
and are used to essentially
determine how much of a similar phase
chemical will leak into the suit. The
whole-garment tests do not evaluate
the chemical permeation properties of
the garments. This is assessed in the
class testing portion of ISO 16602.
For example, the Type 3 whole-garment
test is conducted by having the
test subject march in place with exaggerated
arm-pumping movements,
while slowly turning, in front of a highpressure,
high-volume liquid spray
nozzle. This liquid is tinted with a dark
color to be visible if it penetrates the
test garment. Once the high-pressure
liquid exposure portion of the test is
completed, the outer test garment is
carefully removed and an inner " indicator "
garment is checked for evidence
of liquid penetration, which is
evident by staining from the dark liquid.
Beyond the whole-garment tests,
additional tests are conducted on the
garment's fabric(s) and components to
qualify the class performance level for
the garment against specific chemical
challenges and the physical demands
of the task and work surroundings.
ISO 16602 defines different class levels
of performance for each type of protection
as described below.
Classes of clothing
Within each of the six garment types,
there are also requirements directed
at the mechanical, barrier and basic
flammability properties of the fabrics
and components used to make chemical
protective clothing. Laboratory tests
are used to determine the mechanical
durability, the barrier against specific
chemical hazards, and ease of ignition
of the garment materials. The results
of these tests will fall into a unique
performance class. Each type within
ISO 16602 specifies a combination
of barrier and durability tests levels,
establishing a minimum performance
class for each of the tests to meet the
52 CHEMICAL ENGINEERING WWW.CHE.COM MARCH 2011
specific type requirements. A higher
class rating denotes a higher level of
performance for that property.
The flammability requirements
outlined in ISO 16602 establish a
minimum performance level of flame
spread once the material is ignited; it
does not qualify an ensemble as suitable
for protection against heat and
flame hazards. Specific evaluation of
chemical protective clothing for heat
and flame protection is not in the purview
of ISO 16602. In North America,
relevant standards specifically related
to protective clothing for use near fire
and electric-arc hazards are NFPA
2112 (Standard on Flame-Resistant
Garments for Protection of Industrial
Personnel Against Flash Fire) and
NFPA 70E (Standard for Electrical
Safety in the Workplace).
The class tests are as important as
the whole-garment tests described earlier.
Both are integral to evaluating the
overall integrity and expected performance
of chemical protective clothing.
This integrated rating system aids the
selection of the most appropriate chemical
protective apparel for specific work
tasks. Testing the whole garment and
the individual components separately
ensures the sum of the parts is able to
provide the appropriate protection.
Applying ISO 16602
While understanding ISO 16602 is
critical for safety and occupational
health professionals, it must also be
applied consistently and correctly in
the workplace. Consider the task of
opening a flange in a process pipe containing
a hazardous liquid under pressure.
Even though the pipe should be
depressurized and drained as much as
possible before the flange is removed,
this activity would likely require an
ISO 16602 Type 3 garment for protection
against the possibility that pressurized
liquid exposure might occur.
The Type 3 whole-garment jet test
would have demonstrated the liquidpenetration
resistance of the ensemble
and the performance of the connections
between the garment and other
items of PPE, such as gloves, boots
and respirator. The chemical barrier
performance of the suit material and
components should have been determined
with permeation tests using
http://WWW.CHE.COM
Chemical Engineering March 2011

Table of Contents for the Digital Edition of Chemical Engineering March 2011
