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JCHAS 726 1
Backwards On Campus
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little tempest over the nature of spray cans and squirt bottles in laboratories has brewed up recently. At the heart of the matter, should chemical health and safety managers classify these devices? Are they ‘‘open system use’’ or ‘‘closed system use?’’ Before going further, some definitions will help clarify the debate. [3_TD$IF]Closed System Use: Use of a solid or liquid hazardous material in a closed vessel or system that remains closed during normal operations where vapors emitted by the product are not liberated outside of the vessel or system and the product is not exposed to the atmosphere during normal operations and all uses of compressed gases. [4_TD$IF]Open System Use: Use of a solid or liquid hazardous material in a vessel or system that is continuously open to the atmosphere during normal operations and where vapors are liberated or the product is exposed to the atmosphere during normal operations.
[5_TD$IF]These definitions come from NFPA 400 – the Hazardous Materials Code. NFPA 45 does not define the terms, even though they appear in that document. These definitions become important when a device that isn’t ‘‘open to the atmosphere’’ liberates vapors outside the vessel during normal operations. Spray cans and squirt bottles do just this. The system use classification, whether open or closed, bears on fire code. NFPA 45 defines quantities of flammable liquids in open systems use in some laboratories. Under that code, laboratories may have one-tenth the total quantity of flammable liquids in open system use, compared to the amount that can safely reside in storage. The quantity drops further when the laboratory is multiple stories above grade plane. So a laboratory on the eighth floor of a building gets precious little capacity for flammable liquids for open system use. Designers could escape this dilemma under NFPA 45 by making the laboratory a higher ‘hazard class.’’ This would require more robust fire separation and fire suppression, but would allow the fuel load to rise. Alas, NFPA 45 has begun to adopt the International Fire Code perspective that hazardous materials stocks should reduce at floor levels further above grade plane. So code has closed this avenue to a large lab on the eighth floor. Consider NFPA [6_TD$IF]45’s stated goal: ‘‘to achieve a comprehensive laboratory fire prevention
1871-5532 http://dx.doi.org/10.1016/j.jchas.2014.05.003
and protection program to prevent injury or death to occupants and emergency response personnel.’’ Nowhere in this goal statement will a reader find anything that could withstand the distortion necessary to read ‘‘make it easy for large labs to use spray cans and squirt bottles, even though they discharge their flammable product outside the container.’’ To manage this quandary in an existing lab, one major research facility has commented that they view spray cans and squirt bottles as closed system use. And they support this, apparently, by noting that, if the spray cans and squirt bottles were open system use, their operations could not continue in compliance with fire code. Another analysis defines these devices as closed system use, because they operate inside fume hoods. Since, according to this line of thinking, fume hoods draw air in from the laboratory and discharge it outside, code need not define the air inside a fume hood as ‘‘atmosphere.’’ So, while recognizing that spray bottles discharge their contents, this semantic trickery puts the use of spray bottles in an awkward neutral zone where their nature depends on their location of use. If the laboratory occupant uses them outside the hood, it is open system use. If the occupant uses them inside the hood, it is closed system use. These put the problem backwards. The goal of the code drives the use of squirt bottles and spray cans bottles, not the reverse. Any effort to redefine the nature of the use to suit any given code objective (allowing large labs on high floors of buildings to use spray cans and squirt bottles, for instance) simply erodes the purpose of the code. Chemical health and safety managers have an obligation to objectively analyze those factors in their facilities that create risk. Then, they compare to code and determine the outcome. If that affects operations in a way that causes a conversation with the local fire department and the Authority Having Jurisdiction, so be it. Code has a purpose [7_TD$IF]8– to create conversations among the stakeholders and work toward a common goal. It may turn out that the local fire department doesn’t have heartburn with an eighth floor, 10,000 square foot lab with 80 fume hoods, each storing and using three or four squirt bottles and/or spray cans at once. But, if they do, architects and lab designers should remember who will storm up the stairs to fight the fire.
ß Division of Chemical Health and Safety of the American Chemical Society Elsevier Inc. All rights reserved.
1
Backwards On Campus
A
little tempest over the nature of spray cans and squirt bottles in laboratories has brewed up recently. At the heart of the matter, should chemical health and safety managers classify these devices? Are they ‘‘open system use’’ or ‘‘closed system use?’’ Before going further, some definitions will help clarify the debate. [3_TD$IF]Closed System Use: Use of a solid or liquid hazardous material in a closed vessel or system that remains closed during normal operations where vapors emitted by the product are not liberated outside of the vessel or system and the product is not exposed to the atmosphere during normal operations and all uses of compressed gases. [4_TD$IF]Open System Use: Use of a solid or liquid hazardous material in a vessel or system that is continuously open to the atmosphere during normal operations and where vapors are liberated or the product is exposed to the atmosphere during normal operations.
[5_TD$IF]These definitions come from NFPA 400 – the Hazardous Materials Code. NFPA 45 does not define the terms, even though they appear in that document. These definitions become important when a device that isn’t ‘‘open to the atmosphere’’ liberates vapors outside the vessel during normal operations. Spray cans and squirt bottles do just this. The system use classification, whether open or closed, bears on fire code. NFPA 45 defines quantities of flammable liquids in open systems use in some laboratories. Under that code, laboratories may have one-tenth the total quantity of flammable liquids in open system use, compared to the amount that can safely reside in storage. The quantity drops further when the laboratory is multiple stories above grade plane. So a laboratory on the eighth floor of a building gets precious little capacity for flammable liquids for open system use. Designers could escape this dilemma under NFPA 45 by making the laboratory a higher ‘hazard class.’’ This would require more robust fire separation and fire suppression, but would allow the fuel load to rise. Alas, NFPA 45 has begun to adopt the International Fire Code perspective that hazardous materials stocks should reduce at floor levels further above grade plane. So code has closed this avenue to a large lab on the eighth floor. Consider NFPA [6_TD$IF]45’s stated goal: ‘‘to achieve a comprehensive laboratory fire prevention
1871-5532 http://dx.doi.org/10.1016/j.jchas.2014.05.003
and protection program to prevent injury or death to occupants and emergency response personnel.’’ Nowhere in this goal statement will a reader find anything that could withstand the distortion necessary to read ‘‘make it easy for large labs to use spray cans and squirt bottles, even though they discharge their flammable product outside the container.’’ To manage this quandary in an existing lab, one major research facility has commented that they view spray cans and squirt bottles as closed system use. And they support this, apparently, by noting that, if the spray cans and squirt bottles were open system use, their operations could not continue in compliance with fire code. Another analysis defines these devices as closed system use, because they operate inside fume hoods. Since, according to this line of thinking, fume hoods draw air in from the laboratory and discharge it outside, code need not define the air inside a fume hood as ‘‘atmosphere.’’ So, while recognizing that spray bottles discharge their contents, this semantic trickery puts the use of spray bottles in an awkward neutral zone where their nature depends on their location of use. If the laboratory occupant uses them outside the hood, it is open system use. If the occupant uses them inside the hood, it is closed system use. These put the problem backwards. The goal of the code drives the use of squirt bottles and spray cans bottles, not the reverse. Any effort to redefine the nature of the use to suit any given code objective (allowing large labs on high floors of buildings to use spray cans and squirt bottles, for instance) simply erodes the purpose of the code. Chemical health and safety managers have an obligation to objectively analyze those factors in their facilities that create risk. Then, they compare to code and determine the outcome. If that affects operations in a way that causes a conversation with the local fire department and the Authority Having Jurisdiction, so be it. Code has a purpose [7_TD$IF]8– to create conversations among the stakeholders and work toward a common goal. It may turn out that the local fire department doesn’t have heartburn with an eighth floor, 10,000 square foot lab with 80 fume hoods, each storing and using three or four squirt bottles and/or spray cans at once. But, if they do, architects and lab designers should remember who will storm up the stairs to fight the fire.
ß Division of Chemical Health and Safety of the American Chemical Society Elsevier Inc. All rights reserved.
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