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The hazards of ethylene oxide
LETTERS TO THE EDITOR
The hazards of ethylene oxide
T
o the interesting discussion of toxicity hazards of ethylene oxide1 in a recent issue of this journal I should like to add something about the fire and explosion hazards of the same compound. Ethylene oxide is isomeric with acetaldehyde (CH3CHO) and there is now reason to believe that in some of the earliest investigations of ethylene oxide from over 50 years ago the ethylene oxide had in fact isomerised in storage to acetaldehyde. This conclusion was drawn when about 30 years later experimentalists investigating ethylene oxide decomposition were unable to reproduce results from earlier work, especially cool flame behaviour.2,3
Safety committees
I
n response to your request for stories about safety committees, I offer the following: In 1979, with 10 years of experience in an academic science laboratory, I assumed a new instructional position which included management of a laboratory used by high school chemistry, physics, and general science students, as well as responsibility as lead physical sciences instructor. My new school district had an established K-12 safety committee, which met on a regular basis. What did I find? I found a 10-year-old admonition from a North Central Association of Colleges and Secondary Schools evaluation team that stated, ‘‘The ventilation systems in the laboratories are inadequate, constituting a health hazard, especially in the chemistry lab, and should be corrected.’’ After 10 years, the safety committee had never considered the recommendation. I found a district-wide safety survey, completed in 1978 that FAILED to note:
4
The motivation for the early work referred to, carried out at Imperial College in London, and the more recent (though, by now, still quite distant in time) work in2 and3 carried out in Australia was that ethylene oxide is quite powerfully explosive when mixed with air. At one time the compound was used to rid houses of insects, and it sometimes happened that such endeavours terminated with partial demolition of the house! It is capable of showing detonation behaviour in which case overpressures in excess of 15 bar are possible. By way of perspective it should be noted that overpressures well below 1 bar can be lethal to humans and destroy buildings. In accidental explosions involving ethylene oxide the expected behaviour is deflagration with significant overpressure, the precise overpressure depending on the turbulence which in turn depends on the confinement.
[A] unlocked chemical storage; [B] alphabetical chemical storage; [C] one-half of the gas jets were inoperable; [D] alcohol burners were the primary heating source (perhaps a reason for an observation on the survey that fire was a hazard in the lab); [E] protective eyewear was the wrong type for a chemical setting; [F] there was no chemical inventory; [G] there were no safety policies; [H] spill control materials were lacking; [I] safety education was limited to a collection of posters; [J] ALL of the acids and ALL of the flammables were stored in the same location – under a sink. I found extensive metallic corrosion in all of the storage cabinets. No one on the previous committees had a working knowledge of laboratory and chemical safety. The administrative team had no background in safety issues. The safety ethic was tenuous. As a result, ‘‘safety in the laboratory’’ was dying the death of inertia.
ß Division of Chemical Health and Safety of the American Chemical Society Elsevier Inc. All rights reserved.
Let users of ethylene oxide be conscious of fire and explosion risks as well as toxicity. J.C. Jones Department of Engineering, University of Aberdeen, UK E-mail address: [email protected] REFERENCES 1. Kretchik, J. T. Ethylene Oxide (ETO). J. Chem. Health Safe. 2006, 13(4), 45. 2. Gray, B. F.; Jones, J. C. ‘Ethylene oxide and acetaldehyde oxidations in a wellstirred flow reactor’ Abstracts of Papers, Fourth Australian Combustion Science Conference, Paper 9. The Combustion Institute, Australia/New Zealand Section 1981. 3. Gray, B. F.; Griffiths, J. F.; Jones, J. C. Qualitative aspects of ethylene oxide oxidation in a well-stirred flow reactor. Fuel, 1984, 63, 43–45. doi:10.1016/j.jchas.2007.07.005
Using an action-oriented approach, the science department assumed control of its safety enterprise. During my 24-year tenure with this school district, the science department operated a successful and independent safety program, which was, in effect, our own safety committee. We developed a safety library of print and audio-visual resources; we developed policies and procedures as well as much of the material that went into a chemical hygiene plan that was developed as a regional template; we increased fire protection; we developed an active safety education program including awareness level training in the area of hazardous materials. My department went from a static condition to one that was dynamic and forward moving. And, the district level committee still had no idea of what we were doing. William C.Penker Clark Co., WI Local Emergency Planning Committee, Neillsville, WI 54456, USA doi:10.1016/j.jchas.2007.07.006
1871-5532/$32.00
The hazards of ethylene oxide
T
o the interesting discussion of toxicity hazards of ethylene oxide1 in a recent issue of this journal I should like to add something about the fire and explosion hazards of the same compound. Ethylene oxide is isomeric with acetaldehyde (CH3CHO) and there is now reason to believe that in some of the earliest investigations of ethylene oxide from over 50 years ago the ethylene oxide had in fact isomerised in storage to acetaldehyde. This conclusion was drawn when about 30 years later experimentalists investigating ethylene oxide decomposition were unable to reproduce results from earlier work, especially cool flame behaviour.2,3
Safety committees
I
n response to your request for stories about safety committees, I offer the following: In 1979, with 10 years of experience in an academic science laboratory, I assumed a new instructional position which included management of a laboratory used by high school chemistry, physics, and general science students, as well as responsibility as lead physical sciences instructor. My new school district had an established K-12 safety committee, which met on a regular basis. What did I find? I found a 10-year-old admonition from a North Central Association of Colleges and Secondary Schools evaluation team that stated, ‘‘The ventilation systems in the laboratories are inadequate, constituting a health hazard, especially in the chemistry lab, and should be corrected.’’ After 10 years, the safety committee had never considered the recommendation. I found a district-wide safety survey, completed in 1978 that FAILED to note:
4
The motivation for the early work referred to, carried out at Imperial College in London, and the more recent (though, by now, still quite distant in time) work in2 and3 carried out in Australia was that ethylene oxide is quite powerfully explosive when mixed with air. At one time the compound was used to rid houses of insects, and it sometimes happened that such endeavours terminated with partial demolition of the house! It is capable of showing detonation behaviour in which case overpressures in excess of 15 bar are possible. By way of perspective it should be noted that overpressures well below 1 bar can be lethal to humans and destroy buildings. In accidental explosions involving ethylene oxide the expected behaviour is deflagration with significant overpressure, the precise overpressure depending on the turbulence which in turn depends on the confinement.
[A] unlocked chemical storage; [B] alphabetical chemical storage; [C] one-half of the gas jets were inoperable; [D] alcohol burners were the primary heating source (perhaps a reason for an observation on the survey that fire was a hazard in the lab); [E] protective eyewear was the wrong type for a chemical setting; [F] there was no chemical inventory; [G] there were no safety policies; [H] spill control materials were lacking; [I] safety education was limited to a collection of posters; [J] ALL of the acids and ALL of the flammables were stored in the same location – under a sink. I found extensive metallic corrosion in all of the storage cabinets. No one on the previous committees had a working knowledge of laboratory and chemical safety. The administrative team had no background in safety issues. The safety ethic was tenuous. As a result, ‘‘safety in the laboratory’’ was dying the death of inertia.
ß Division of Chemical Health and Safety of the American Chemical Society Elsevier Inc. All rights reserved.
Let users of ethylene oxide be conscious of fire and explosion risks as well as toxicity. J.C. Jones Department of Engineering, University of Aberdeen, UK E-mail address: [email protected] REFERENCES 1. Kretchik, J. T. Ethylene Oxide (ETO). J. Chem. Health Safe. 2006, 13(4), 45. 2. Gray, B. F.; Jones, J. C. ‘Ethylene oxide and acetaldehyde oxidations in a wellstirred flow reactor’ Abstracts of Papers, Fourth Australian Combustion Science Conference, Paper 9. The Combustion Institute, Australia/New Zealand Section 1981. 3. Gray, B. F.; Griffiths, J. F.; Jones, J. C. Qualitative aspects of ethylene oxide oxidation in a well-stirred flow reactor. Fuel, 1984, 63, 43–45. doi:10.1016/j.jchas.2007.07.005
Using an action-oriented approach, the science department assumed control of its safety enterprise. During my 24-year tenure with this school district, the science department operated a successful and independent safety program, which was, in effect, our own safety committee. We developed a safety library of print and audio-visual resources; we developed policies and procedures as well as much of the material that went into a chemical hygiene plan that was developed as a regional template; we increased fire protection; we developed an active safety education program including awareness level training in the area of hazardous materials. My department went from a static condition to one that was dynamic and forward moving. And, the district level committee still had no idea of what we were doing. William C.Penker Clark Co., WI Local Emergency Planning Committee, Neillsville, WI 54456, USA doi:10.1016/j.jchas.2007.07.006
1871-5532/$32.00