The 2019 edition of NFPA 45: Standard On Fire Protection For Laboratories Using Chemicals has been released.
Fires in Laboratories Handling Chemicals
A pyrophoric material can spontaneously ignite in air. According to NFPA 45-2019, a pyrophoric gas will spontaneously ignite in air at or below 54.4°C (130°F), and a phosphoric reagent ignites at 54°C (130°F) or below on exposure to water vapor in air-producing flammable gas and heat.
Also, for which most laboratory professionals are equipped with the knowledge to prevent, various chemicals, when mixed together, can yield flammable or combustible results. For example, hydrides, such as sodium hydride, when combined with water, can form flammable hydrogen gas; silver salts, when mixed with ammonia in the presence of a strong base, can generate an explosively unstable solid; alkali metals—sodium, potassium—with water can yield hydrogen gas; oxidizing agents, like nitric acid, with reducing agents, like hydrazine, can cause fires and explosions; and hydrogen peroxide/acetic acid mixtures, when heated, can explode.
However, a disregard for chemical equations isn’t the only culprit of fires or explosions in laboratories. In fact, two-thirds of all lab fires are caused by electricity. With all these factors in mind, it is not only necessary to assure fire protection provisions for laboratories using chemicals, but it is crucial that those provisions are unique to such facilities. Thankfully, NFPA 45 has been meeting this need since its first publication in 1975.
The Standard on Fire Protection for Laboratories Using Chemicals
NFPA 45-2019 assures the protection of life and property through the prevention and control of fires and explosions that involve the use of chemicals in laboratory-scale operations. In meeting this purpose, the standard helps to control hazards and protect personnel from toxic, corrosive, and other harmful effects brought about from chemicals that personnel can be exposed to after a fire or explosion. It limits injury to occupants at the point of fire origin, injury to emergency response personnel, and property loss to a maximum of a single laboratory unit.
NFPA 45-2019 applies to laboratory buildings, units, and work areas, as well as all educational laboratory units and instructional laboratory units, in which any quantity of chemicals, as defined in NFPA 704 with one or more of the following hazard ratings, is handled or stored: health—2, 3, or 4, flammability—2, 3, or 4, or instability—2, 3, or 4.
NFPA 45-2019 revises the 2015 edition of the same standard for the fire protection of laboratories that use chemicals. It is a sizeable revision, with numerous substantial changes that distinguish it from the previous edition.
The 2019 edition of NFPA 45 contains the following changes:
- Definitions for use, closed system use, and open system use have been added and used throughout the standard.
- To address laboratory units in health care facilities, the standard includes flammable and combustible liquid quantity limitations, lab unit classifications, fire separations, and specific provisions for distillation and solvent recycling equipment and tissue protectors.
- Area limitations for lab units were removed, due to the quantity of flammable liquids being limited by volume and density limits.
- The standard now clarifies that curbing of laboratory floors can be used to prevent liquids from migrating to lower floor levels. New annex text was added to list other preventative means.
- The standard now clarifies that the methods for exit doors need to comply with NFPA 101.
- The section on emergency lighting was revised to call for emergency lighting in all laboratory work areas, and not just those that need a second means of access to an exit.
- The standard now clarifies information on Class I wet standpipe systems. It also clarifies manual fire alarm systems, which now include all buildings with laboratory units.
- Terminology related to flame-resistant clothing has been revised to align with NFPA 2112.
- Sound attenuation devices are not prohibited within laboratory exhaust systems.
- Laboratory exhaust ducts, dampers, and exhaust ducting through fire barriers are now addressed to clarify the installation of exhaust ducts through fire-rated barriers and to align with the current editions of NFPA 90A and NFPA 91.
- Inspection, testing, and maintenance of fire extinguishing systems in ductwork or chemical fume hoods was revised from a specified time interval to a schedule appropriate for the type of system.
- A new retroactivity clause has been added to clarify that the Chapter 8 on chemical storage, handling, and waste disposal contains operational information that needs to be applied to existing laboratories, and not only new construction.
- Hazardous chemical containers stored and handled in laboratory work areas are now limited to 20 L (5 gal). Previous language about limiting spill scenarios was ambiguous.
- For chemical storage, a minimum inspection frequency of 1 year was added.
- Annex material was added to reinforce the need to evaluate the effects of any mixing of wastes, to clarify the process of dispensing Class I liquids in a ventilated area, to explain why pyrophoric reagents and water-reactive materials in glove boxes need to be sealed in airtight containers when not in use, to describe flame-jetting hazards, and to explain the need for hazard evaluations and risk assessments before new or changed experiments.
- Language was added to reference NFPA 30 for quantities of flammable and combustible liquids within inside liquid storage areas.
- Information for gas cylinders was aligned with NFPA 55.
- In clarifying information on emergency gas shutoffs and overpressure protection, new language was added to address the potential explosion hazards associated with mixing flammable and oxidizing materials.
- For consistency, the sections on heating operations and heating equipment were combined into one section. In this new section, 11.3.3, new information was added for performing hazard analysis and risk assessment before the use of pressure-containing equipment.
NFPA 45-2019: Standard On Fire Protection For Laboratories Using Chemicals, 2019 Edition is available on the ANSI Webstore.