New thin-film intumescent fire protection products are the wave of the future, but only when uniform standards are in place.
Over the past couple of years, thin-film intumescent fire protection has found wider acceptance in specifications across North America and around the world. Architectural designers and structural engineers have discovered the benefits of this new technology. The specific features that make this group of products attractive to the architects and engineers include a “paint-like” think coatings, i.e., thin-film; a durable finished surface; a wide
range of finish colors
and the ability to leave structural
steel exposed. These qualities have
helped this family of products to create
its own “niche” in the passive fire protection
business. This niche is also the
fastest growing segment in the passive
fire protection business. With the recent
acceptance of thin-film intumescents in
lieu of traditional spray-applied fireresistive
materials, many questions are
Installed cost is a prime factor in the
selection of a passive fire protection product/
system. While architectural designers
like the freedom provided by the use of
thin-film intumescents, the question
arises whether the increased cost may
outweigh the benefits. Increasingly, thinfilm
intumescent specifications are showing
up in the budget process, and are
being used in schools, offices, retail establishments,
airports and retrofit projects.
This upward trend may be due to cost efficiencies
available in the new generation
of thin-film intumescent products that
have been recently introduced.
Historically, the primary cost hurdle has
been the installation labor costs. Job site
limitations and complex application procedures
also add to the costs. Outdated
mastic intumescent technology required
adhesive base-coats or glass fiber mesh
reinforcement to meet the fire test standards.
But the new generation of thinfilm
intumescents can be applied in
thicker coats and they normally do not
require any complex reinforcements,
making them more cost efficient. The
necessary performance properties have
been engineered into these products. The
new thin-film intumescents are reducing
installation time; therefore, application
costs are dramatically reduced.
Steel Section Shapes and Sizes
From a structural engineering standpoint,
hollow-shaped steel and three hour
fire-rating requirements further
increased the demands on this new technology.
Thickness alone is not the only
cost barometer. Architects need to
increase steel sizes in order to reduce
intumescent thickness. By adding this
critical design step, projects will yield
further material cost savings.
Intumescent Char Properties
Compared to the older products, the
char generated by the new thin-film
intumescent products demonstrates far
greater integrity in a fire to avoid cracking,
resist delaminating and adhere to
smaller steel shapes and sizes.
This next generation of thin-film intumescent
coatings could revolutionize the
fire protection industry.
Uniform Testing Standards
The long-term survival of thin-film intumescents
will be determined by their
ability to meet the stringent environmental
exposure testing requirements.
These tests are paramount to the survival
of thin-film intumescents because they
assure long-term thermal performance.
Currently, Underwriters Laboratories,
Inc. is the only not-for-profit independent
testing agency to mandate this critical
step for classification.
A recent article, “The Significance of the
UL Classification Mark on Thin-Film
Intumescent Coatings,” by the regulatory
authorities at UL tells us that “To
obtain a UL classification, thin-film
intumescent coatings must . . . demonstrate
fire resistive performance after
being subjected to several simulated
environmental conditions. These conditions
include accelerated aging . . . elevated
humidity, ultraviolet light,” etc. to
ensure that the thin-film intumescent
coating will perform after it ages.
Often, the re-engineering of older thin-film intumescent coatings requires the
use of a topcoat to provide a protective
barrier to meet these essential life safety
assurances. Topcoat requirements limit
the type of finishing material for all subsequent
coats and significantly add to
the cost burden. New generation thinfilm
intumescents can meet these standards
without the need for a topcoat.
UL Follow-up Service Procedure
Also unique to UL is its follow-up Service
Procedure for all tested products.
UL conducts quarterly audits at the
manufacturer’s facilities to ensure materials
are manufactured in accordance
with the same specifications as the products
tested at their laboratories. In short,
this process confirms that identical raw
materials are utilized, the manufacturing
process is performed correctly, and the
finished product meets all specifications.
ULs follow-up Service Program ensures
that manufacturers maintain the highest
standard of product processing, raw
materials and finished materials
throughout the product’s lifetime.
No other major testing
laboratory within the
country offers such a
comprehensive and thorough
means of product
assurance and substantiation.
Product Formulation and Environmental Concerns
The new generations of thin-film intumescent
coatings are water-based products
because of the following:
- The use of solvents like xylene and ethylbenzene
(known carcinogens) are eliminated.
- Removal of HAZMAT issues, in shipping,
storage, spill clean-up and waste
- Compliance with VOC rules in all 50
Elimination of chlorinated products and
chlorine gas issues in a fire.
New water-based thin-film intumescents
have been designed around the UL requirements
to establish a new technological standard
for environmental safety.
The new generations of water-based thinfilm
intumescents are applicator friendly Job
site concerns regarding welding, drying time and ventilation
during application of solvent-based products
are not issues with these new water-based products.
Typically, the water-based coatings dry in
one third of the time versus solvent-based
products. The ability to quickly build up
thickness substantially reduces labor costs.
Trade scheduling can be more streamlined
and flexible with the new water-based thinfilm
The new generation of water-based thinfilm
intumescent fire protection products
will virtually eliminate the common concerns
associated with solvent-based products.
UL Test Standards
UL, through adopting ASTM standards, has set
the fire test standards for the past few decades and
has set the precedent by which all thin-film
intumescent products must be measured.
The UL classification ensures
that all listings are based
on full-scale fire tests conducted
in accordance with
UL 263 (ASTM El 19).
Code agencies have long
raised concerns over
small-scale or assessment
reports not necessarily
based on full-scale
ASTM E119 fire tests. A
of the moral and ethical value
in the UL environmental testing
requirements is essential to the survival of
thin-film intumescent technology in structural
fire protection. Some participants in
the marketplace are proposing extrapolated
thicknesses beyond the UL-tested parameters
of steel size and coating thickness, which
are potentially life threatening and must not
be approved without legitimate justification
via fire testing.
Passive fire protection is a life safety discipline.
Therefore, the long-term survival of
thin-film intumescent technology will
depend on the industry—code bodies, regulatory
agencies, manufacturers, contractors,
applicators and architects—adopting
a uniform fire testing and environmental
About the Author
Charles A. Nuzzo is product manager, Intumescent
Coatings, with Isolatek International,