Chemical Engineering February 2014 - 30

Chemical
Department Editor: Scott Jenkins
orkers in the chemical process
industries (CPI) can wear chemical
protective clothing to protect
themselves from exposure to potentially
hazardous chemicals in the form of
vapor, liquid and solid particles. While
chemical protective clothing has not
been regulated to the extent that safety
glasses, hard hats and some other forms
of personal protective equipment (PPE)
have been, an international standard is
available for classifying the performance
of chemical protective equipment.
When testing chemical protective clothing
(CPC), a two-pronged approach is
taken, where the whole garment is tested
as well as the individual components.
Testing both separately is an integral part
of evaluating the overall integrity and
expected performance of the CPC.
W
ISO 16602
ISO 16602 ( " Protective clothing for
protection against chemicals-classification,
labeling and performance requirements " )
provides an objective system
to appropriately test, classify and label
chemical-protective apparel. The requirements
outlined in ISO 16602 provide a
common language for the performance
of chemical protective clothing.
ISO 16602 designates minimum
performance levels of protective clothing
for six types of chemical hazards. The
performance requirements are based on
results from existing test-method standards,
and the garment type designation
is based upon the physical state of
the hazard (vapors, liquids, aerosols or
particles; Figure 1). The garment types
are as follows:
* Type 6: Limited protection against
liquid mist
* Type 5: Protection against airborne
solid particulate chemicals
* Type 4: Protection against liquid
aerosols
* Type 3: Protection against pressurized
liquid chemicals
* Type 2: Non-gas-tight protection
* Type 1: Gas-tight (vapor-protective) protection
against chemicals and vapors
and toxic particles
Although ISO 16602 permits a range
of performance levels for a series of key
properties, it also establishes a minimum
level of performance for each major
type of hazard.
Each workplace environment is
unique, and the ISO 16602 Standard
does not consider all specific hazards
that may be present. Safety and occupational
health professionals should
consider hazards that are specific to
their work conditions and then consult
the ISO 16602 standard to determine
the minimum requirements of chemical
protective garments used in the particular
situation.
Six " types " of CPC outlined in ISO 16602
Protective Clothing
Type 1
Type 2
Type 3
Type 4
Non
Type 5
Type 6
Limited
protection
against
liquid mist
Protection
against
airborne,
solid
particulate
chemicals
Protection
against
liquid
aerosols
Protection
against
pressurized
liquid
chemicals
gas-tight
protection
Gas-tight
protection
against
chemicals
and vapors
and toxic
particles
Type indication doesn't tell you everything
about the performance of the CPC. It only
tells that it meets the minimum requirements
of a particular " type " certification
Figure 1. ISO 16602 provides an objective system to appropriately test, classify and label
chemical-protective apparel. The standard designates minimum performance levels of protective
clothing for six types of chemical hazards. The garment type designation is based upon the
physical state of the hazard (vapors, liquids, aerosols or particles)
ISO 16602 focuses exclusively on
typical chemical hazards and protective
clothing requirements for those hazards,
so each work situation will likely require
additional forms of PPE, possibly including
footwear, gloves, face protection,
fall protection and respirators.
Hazard assessment
A hazard assessment provides a basis
for understanding what chemical protective
clothing and other PPE are necessary
to protect the workers operating
in specific situations. The environment,
chemical hazard and work activity must
be considered in selecting the protective
clothing - including the fabric, seam
type and garment design - that is most
suitable. The goal is to select clothing
with adequate protection, but without
overprotecting a worker with unnecessary
clothing, which can result in heat
stress, reduced field of vision, restricted
mobility and increased physical exertion
for the wearer, as well as higher costs
for the employer.
Performance testing
When setting the requirements for each
clothing type in ISO 16602, the entire
garment is tested in addition to the
individual components.
Whole-garment tests. During whole-garment
tests, a human subject wears the
test garment and accompanying PPE,
such as gloves, boots and respirator.
The subject is exposed to non-hazardous
test chemicals inside an enclosed chamber
while 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). Test chemicals are used to
determine how much of a similar-phase
chemical will leak into the suit.
Class tests. Whole-garment tests do
not evaluate the chemical permeation
properties of the garments. This is assessed
in the class testing portion of ISO
16602. Beyond the whole-garment tests,
additional tests are conducted on the
garment's fabric(s) and components to
qualify the class performance level.
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 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.
Heat and flame protection is not in the
purview of ISO 16602, but is covered
within fire safety standards from the National
Fire Protection Association (NFPA;
Quincy, Mass.; www.nfpa.org).
Editor's note: This " Facts at your Fingertips " column
was adapted from the following article:
Lovasic, S., Chemical Protective Clothing,
Chem. Eng., March 2011, pp. 51-53.

http://www.nfpa.org

Chemical Engineering February 2014

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