Liquid-Tight Flooring in Laboratories

One of the most common accidents within laboratories involves the spilling or leakage of hazardous chemicals. As an added safety precaution to limit the impact of a spill or leak, NFPA 45, Standard on Fire Protection for Laboratories Using Chemicals, contains provisions for laboratory flooring in order to contain a spill to the floor of origin and prevent the spread of liquid to any spaces below. For designers, some questions naturally arise: What are the requirements for flooring within a laboratory, and what are the options for compliance?

Section 5.1.5 of NFPA 45 (2019 edition) addresses flooring within laboratories. Specifically, this section requires laboratory floors, floor openings, floor penetrations, and floor firestop systems to be sealed or curbed to prevent liquid leakage to lower levels (i.e., liquid-tight). Further, the sealing material is required to be compatible with the chemicals being stored or used within the laboratory, or a program is required to be in place to inspect and/or repair any sealing materials, if necessary, after exposure to a chemical spill or leak.

The spread of liquid to an area below can be prevented by permanent means such as curbs around floor penetrations, trenches at doors, and/or curbing at the laboratory perimeter to raise the start of the walls. The use of resinous floor coatings such as epoxies or other impermeable floor systems is also recognized as an option. Construction sealants can also be utilized, however, sealants are more susceptible to degradation depending on the specific sealant, the type of chemical spilled, and the exposure time to the chemical, such that an inspection and maintenance regimen may be necessary where using sealants.

Penetrations through floors are also required to be protected to prevent spills from reaching lower levels. While a typical firestop system will prevent the spread of smoke and hot gases, a W-rated firestop system can be utilized to prevent the passage of liquid. These systems may not be chemically resistant, however, they may be able to stop chemical leakage for a sufficient period of time to clean up a spill. As with sealants, an inspection and maintenance regimen may be necessary to ensure the integrity of the system is maintained. If a firestop system is not liquid-tight, other provisions, such as curbing, will be necessary.

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Application of any information provided, for any use, is at the reader’s risk and without liability to Code Red Consultants. Code Red Consultants does not warrant the accuracy of any information contained in this blog as applicable codes and standards change over time. The application, enforcement and interpretation of codes and standards may vary between Authorities Having Jurisdiction and for this reason, registered design professionals should be consulted to determine the appropriate application of codes and standards to a specific scope of work.