Carboline has announced the release of Thermo-Sorb HB, a two-component, high-build, elastomeric
intumescent coating for shop or field application rated for up to 3.5 hours of fire resistance for
interior or exterior structural steel.
Based on patented elastomeric intumescent technology, Thermo-Sorb HB is ideal for demanding
project conditions with outstanding resistance to damage from application and transit through to
project completion. The solvent-based coating cures quickly, achieving weather resistance in just
one hour to complement accelerated open-frame construction.
This combination of features makes Thermo-Sorb HB ideal for either shop or field application,
providing essential flexibility for large-scale, fast-track construction projects.
“This new product enhances Carboline’s industry-leading Thermo-Sorb portfolio, empowering
construction and design teams to optimize fire protection solutions in a wider range of
environments, fire durations, and segments to meet evolving project demands,” said Michael
Hollman, Global Intumescent Product Manager.
Thermo-Sorb HB meets or exceeds UL/ULC 263 (ASTM E119) and CAN/ULC-S101 testing and is listed
for wide flange columns, tube columns, pipe columns, and restrained and unrestrained beams in the
maximum allowable load condition or limit states design provisions. It is rated for up to 3.5 hours of
fire resistance for certain designs.
Additionally, Thermo-Sorb HB contains innovative Optifire® taggant technology, allowing for real-
time traceability and warranty protection. Optifire technology assures performance because the
pigments are detectable for the duration of the material’s service life, from wet film and dry film to
the resultant char after a fire.
“Formulating Thermo-Sorb HB to include Optifire traceability technology marks a novel
advancement in the coatings industry and in construction in general,” Hollman said. “Most
construction materials are only traceable from cradle to gate, with all visibility lost once they arrive
on-site. By contrast, Thermo-Sorb HB with Optifire provides real-time traceability from cradle to
grave, delivering comprehensive assurance for architects, inspectors, and owners.”