Its important to know if the oven is rated for flammable solvent/vapors. In another life I inspected a facility that used methanol as a binder in an oven that was not rated for flammables. The large door ended up across the room & the yellow powder was everywhere. Kim Auletta Lab Safety Specialist EH&S Z=6200 Stony Brook University kauletta**At_Symbol_Here**notes.cc.sunysb.edu 631-632-3032 EH&S Web site: http://www.stonybrook.edu/ehs/lab/ Remember to wash your hands! From: "Tsiakals, Nicholas John"
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU Date: 07/06/2010 03:16 PM Subject: Re: [DCHAS-L] Sol-gel drying process Sent by: DCHAS-L Discussion List Can’t say I’m familiar with the chemistry. Even so, I would turn these questions back at the lab(s) involved: What were the intermediates/byproducts produced? What was being evaporated at the hood? At the oven? I question the hot plate boil-off and the convection oven for solvent. (If flammable atmospheres, then intrinsically safe electrical components required.) (Did the convection oven vent to the room?) Solvent/vapor recovery would be more robust – required at larger scale. Does the person involved appreciate: Consequences were limited in this case by unwitting accidents of scale and access. I realize this is unrefined, but this is where I would start with the ideas/questions. -Nick From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**LIST.UVM.EDU] On Behalf Of Perry Cooper Sent: Tuesday, July 06, 2010 11:04 AM To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU Subject: [DCHAS-L] Sol-gel drying process Sharing an incident. Anyone want to chip in on recommendations? J General lab exhaust through the fume hood. Some equipment exhausted with localized flex duct but not the oven. Adjacent areas complained of strong alcohol odor. "….. intent to prepare a batch of fine particulate size aluminum oxide via the sol gel process. The components were an organometallic (aluminum sec- butoxide), a solvent (2-propanol) and water. 1.5l of 2-propanol was placed in a porcelain-lined steel container. 4.5kg of aluminum sec-butoxide was added to the solvent while mixing. After these components were thoroughly mixed, 1.1l of water was added resulting in the formation of AlOH particles from the organic precursor. At this point, the composition was a viscous slurry. In order to reduce the solvent content, the container was placed on a hot plate inside the fume hood. The composition was heated (temperature unknown but estimated to be 70-80°C) for approximately 4 hours. At the end of this period, most of the solvent had evaporated, leaving a slightly moist "cake". In order to remove the remaining solvent, the container was taken to room xxxxx and placed in a convection oven. I partially covered the container with a lid to allow venting and to prevent any swirling debris from contaminating the material. Oven temperature was set at 130°C and the general exhaust in this room was turned on. My intent was to let the material dry overnight and I left for the day. When I returned the following day, I checked the oven and it was apparent that there had been an accident at some point after I left. I later learned that there had been a small explosion and fire. I believe the fire was confined to the oven and was extinguished by covering the container with the lid. The oven door was bent when it swung open and contacted the control enclosure but no other damage is apparent. In the past, I have used these same procedures and equipment to make similar compositions without incident…." Regards, Perry _______________________________ Perry D. Cooper, MS, HEM, CCHO Manager - HSE - JHU The Johns Hopkins University Health, Safety & Environment www.hopkinsmedicine.org/hse Homewood Campus Safety Office 3400 N. Charles Street G04 Wyman Park Bldg Baltimore, MD 21218 Office: 410-516-2345 Fax: 410-516-4314 www.jhu.edu/safety _______________________________ This transmission may contain privileged and confidential information. Be advised that any disclosure, copying, distribution or other use of this information is strictly prohibited.
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