Document nBpXVyrEKkMN0xz89ebbJK86

AR226-2048 / / Ta-Wei Fu 07/30/2001 08:01 AM . To: John E Crum/SE/DuPont@DuPont cc: Ta-W el Fu/CL/DuPont@DuPont, Roger J Zipfel/AE/DuPont@DuPont Subject: Re: C-8 sampling D John, Maybe I did not make my points clear on the phone so I would like to clarify it here: 1, The vapor pressure of the C-8 solution is very very low so it is impossible to be the root cause of the high level of C-8 measurred In the 124 building. 2. The only possible explanation for the presence of high amount of C -8 measurred is that there is some dried C -8 powder floating around inside the B-124. This could be from some residue C-8 solution dried on the floor or equipment. A good wash down on the equipment and floor should help minimize this possibility. In the air sampling, if w e happened to collect a few floating particles occassionally, the results will definitely be on the high side. Hope the above can help clarify what I intended to convey in the phone conference last week. Please let me know if there is still confusing to you. Roger has also correctly pointed out that the current scrubber vent could be a real root cause of what we have seen. T a-W ei John E Crum John E Crum 07/27/2001 07:54 AM To: Ta-Wei Fu/CL/DuPont@OuPont, Roger J 2ipfel/AE/DuPont@DuPont cc: Subject: C-8 sampling Please note the attached. The samples seem to be consistantly on the high side. I would like to understand what is causing this? T a-W ei you inidicated it must be from dry powder over the phone yesterday because of the high vapor pressure of C-8, but somehow I rem em ber in the old days of us saying that C -8 azeotroped with water in the dryer and that we needed w ater in order to help remove the C -8 from the polymer. Otherwise the dryer could not "evaporate" C-8 and it would remain with the polymer. M y concern is the extra exposures that will occur with the new R O units!! W e will be releasing a lot more dilute C-8 liquids to the floor area in the building and determine if this is coming from vapor concentrations rather than particle concentrations. Dried C-8 particles can be kept to a minimum by hosing down the floor well, but we will have difficulty in keeping vapor concentrations down. And whether this is from the present units or new units, I would assume that having this restriction is going to be a long term problem/concern that we m ay want to deal with. Can we live with having a 15 min exposure limit in the room for the long term? . . . ----------------- -------Forwarded by John E Crum/SE/DuPont on 07/27/2001 07:34 AM -- --------------------- ----- -- Donald E McKown ' 07/26/2001 05:03 PM EID339032 To: John E Crum/SE/DuPcmt@DuPont, John S Hammond/HO/DuPont@DuPont oc: Subject: C-8 sampling Forwarded by Donald E M eKown/SE/DuPont on 07/26/2001 05:03 PM Jack L Offenberger 07/26/2001 01:21 PM To: cc: Subject: James W Hunt/CL/DuPont@DuPont Donald E McKown/SE/DuPont@DuPont, Becky Szakats Dlnes/CL/DuPont@DuPont, Nicholas K Reed/AE/DuPont@DuPont, Mark D Cothem/SE/DuPont@DuPont, Anthony J Playtis/CL/DuPont@DuPont, Fred M Lentz/SE/DuPont@DuPont C-8 sampling W e have had some complaints regarding the posted signs in the C-8 Recovery building requiring Respiratory Protection while working in the building over a 15 minutes tim e frame. W e have done some extra sampling in the building to see if the levels are low enough to remove the signs. Below are the results of the most recent sampling. DATE 7/3 7/20 7/20 7/24 7/24 RESULT 0.31 0.52 0.46 0.48 0.52 % of AEL 55.4 92.9 82.1 85.7 92.9 Sam ple Routine sample Extra Sampling Extra Sampling Extra Sampling Extra Sampling Out of the last 25 samples taken in that area, 4 have been over the AEL, another 13 have been well over 1/2 of the AEL and 8 were less than 1/2 the AEL. Should we continue with the extra sampling? Based on these results, I lean towards keeping the respiratory protection requirement. Thanks -J a c k Offenberger, Teflon S&OH Coordinator ext. 4959 EID339033