Here are some of the points regarding EPOXY PRODUCTS IN RELATION TO
FIRE and are as follows:
- Epoxy resin and hardeners are classified non-flammable because their flash points are greater than 200°F and they evaporate slowly. – Hence safe to use at site.
- The hardener & resin
components are non-flammable liquid, but may be corrosive or toxic at
liquid stage. If the epoxy is mixed as per manufacturer’s specification
and allowed to dry / cure, it will a product which cannot be
assigned a P or U waste code.
- In general, epoxy
products fully cured will be more heat & chemical resistant. The
strength of epoxies is degraded at temperatures above 350 °F (177 °C).
- Epoxies bonds the
substrate in three ways:
- Mechanically, because the
bonding surfaces are roughened
- By proximity, because
the cured resins are physically so close to the bonding surfaces that
they are hard to separate
- Ionically, because the
epoxy resins form ionic bonds at an atomic level with the bonding
surfaces.
Hence, act as good system
even at high temperature & chemicals attack.
- Epoxies can be
re-formulated as conductive or dissipative flooring / coating to avoid the
accidents casing by the Electro static charges.
- Study at NUCLEAR
REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 August 13, 2007:
- PURPOSE: The U.S.
Nuclear Regulatory Commission (NRC) is issuing this information notice
(IN) to inform addressees of a fire protection issue raised by NRC
inspectors at two nuclear power plants that involves the combustibility
of epoxy floor coatings over the concrete floors in various plant areas.
- GDC 3 states, in part,
“Non-combustible and heat-resistant materials shall be used wherever
practical throughout the unit, particularly in locations such as the
containment and control room.” However, GDC 3 does not preclude the
use of combustible materials. Examples of combustible materials found in
nuclear power plants are electrical cable insulation and jackets,
lubricants, hydraulic and control fluids, diesel generator fuel oils,
charcoal and other filters, and flammable gases. In general, when such
materials are properly managed, are accounted for in the plant design and
operation, and are incorporated as integral components of the plant fire
protection program, including the fire hazard analysis, they may be
acceptable. NRC inspectors at two facilities raised an issue involving
the fact that epoxy floor coating may or may not be considered
combustible in the NRC-approved fire protection program depending on (1)
the thickness with which the coating is applied, and (2) an
independent laboratory testing of the flame spread rating for the
specific epoxy floor coating. The inspectors found that although
these licensees considered the epoxy floor coatings non-combustible, they
had not evaluated and controlled the thickness with which the epoxy
coating was applied on floors. When subsequent evaluation and testing by
these licensees showed that the epoxy coating must be considered
combustible, these licensees performed a fire hazards analysis that
incorporated the combustible epoxy coating in accordance with their
NRC-approved fire protection program.
- CONCLUSION: The
problem of epoxy floor coatings that are considered combustible can be
avoided by using a product with a low flame spread rating,
applying it in accordance with the manufacturer’s/ vendor’s
recommendations, and providing plant procedural controls for applying the
coating to ensure it does not exceed recommended thickness. Coatings that
are applied thicker than a manufacturer’s recommendations may exceed the
listed flame spread rating.
- For more details: https://www.nrc.gov/docs/ML0719/ML071920090.pdf
Thanks for the explanation!
ReplyDeleteThat was quite informative
Elcometer 510