Thank you everyone, who responded both on-line and off with suggestions about removing the build up of acetic acid in our cold film storage vault. From conservators who work with plastics there is a concern about the use of micro sieves / zeolites for acetic acid because they can also remove plasticizers in film which would make the film base shrink. We use STiL vented film cans for our moving image film, so this is a concern. Since most of our collection is flat negatives stored in individual 3 flap envelopes and inside 66 pt. Micro Chamber board boxes with fully telescoping lids, there would be little direct exposure of the acetate film to the zeolite activity for these materials. Our chamber is not vented, so there is nothing we can place in a vent stream. We will likely introduce a free-standing industrial air filtration unit to initially clean the air with many changes of charcoal filters. https://www.buyjanitorialdirect.com/Products/Phoenix-Mini-Guardian-HEPA-System__THS-lbspc-4024774.aspx?utm_medium=ppc&utm_term=&utm_campaign=S+-+Brand+Names&utm_source=adwords&hsa_ver=3&hsa_cam=1002603068&hsa_ad=388635683997&hsa_net=adwords&hsa_src=g&hsa_tgt=pla-294682000766&hsa_kw=&hsa_mt=&hsa_grp=74712301410&hsa_acc=1580534979&gclid=EAIaIQobChMInqeWjOmR5QIVkYrICh0kzARdEAQYASABEgLPhfD_BwE <https://www.buyjanitorialdirect.com/Products/Phoenix-Mini-Guardian-HEPA-System__THS-lbspc-4024774.aspx?utm_medium=ppc&utm_term=&utm_campaign=S+-+Brand+Names&utm_source=adwords&hsa_ver=3&hsa_cam=1002603068&hsa_ad=388635683997&hsa_net=adwords&hsa_src=g&hsa_tgt=pla-294682000766&hsa_kw=&hsa_mt=&hsa_grp=74712301410&hsa_acc=1580534979&gclid=EAIaIQobChMInqeWjOmR5QIVkYrICh0kzARdEAQYASABEgLPhfD_BwE> This would be done while testing for off gassing of acetic acid vapors from the box board itself, which has likely exhausted the capacity to absorb the off gassing. These would be replaced over a period of time. Once testing reveals the initial period of filtration is complete we can report the process and timeline back to the community. Thanks again, and other thoughts and comments are welcome.
------------------------------ Ramona Duncan-Huse Senior Director, Conservation Department Indiana Historical Society Indianapolis IN (317) 234-0093 ------------------------------ ------------------------------------------- Original Message: Sent: 10-14-2019 12:12 From: Tara Kennedy Subject: cold film storage off gassing Hi Ramona- Is there any filtration in the air handling unit that controls the cool storage? Adding gas phase filtration to the AHU would take care of the problem. Look for a filter that has carbon or zeolites and change the filters at least quarterly. As for the Microchamber materials, they appear to have outlasted their useful life and need to be switched out. Going forward, if gas phase filters are added to the unit along with additional air movement, you may not need them. Regular archival housings may be sufficient. Feel free to contact me if you have additional questions. Tara ------------------------------ Tara Kennedy Preservation Services Librarian/ Preventive Conservator Yale University Library New Haven CT (203) 432-4335 Chair of AIC Health and Safety Co-Chair of the NHR Working Group ------------------------------ Original Message: Sent: 10-08-2019 16:06 From: Ramona Duncan-Huse Subject: cold film storage off gassing We have a chilled film storage unit which was purpose built for our archive to specifications recommended for moving image and sheet film. Aetate sheet film negatives have been stored in Micro Chamber boxes for over 15 years in this 300 cubic foot unit. Temperature and RH have varied over the years but set points are 50F and 35% RH. We are an active research archive so the vault is accessed weekly and film boxes are staged in Styrofoam coolers for 24 hours prior to use. Our AD tests on random samples indicate film deterioration at level 1. We are experiencing a buildup of vinegar/acetic acid vapors in this chilled vault. I have not come across reference in professional literature that indicate ways to actively or passively remove the odor of off gassing. I understand freezing temperatures would be best for the film and to further reduce off-gassing, but this is not a capability of our vault. I also understand specifications for these units did not include ventilation as a necessary feature. A theory based on the idea of level 1 deterioration in the film, is that the Micro Chamber storage boxes are actually off-gassing the vapors they have trapped over the years. Acetic acid vapors are damaging to the general environment but can also cause further damage to dyes in color film. Are there other institutions experiencing a buildup of vapors in the closed environment of a chilled acetate film storage vault, and have you any information about how to passively or actively remove these particular molecules? If zeolite pellet technology is being used I did see a reference to NaX-13X molecular sieve as being the most efficient for acetic acids but do not understand how to efficiently employ it in the space. The other aspect would be to change out our boxes if these have reached a capacity for absorbing off gassing. Anyone willing to share their thoughts or experiences would be appreciated. Thank you! Ramona Duncan-Huse Senior Director, Conservation Eugene and Marilyn Glick Indiana History Center Indiana Historical Society 450 W. Ohio Street Indianapolis, IN. 46202 317-234-0093 [email protected] <[email protected]> Discover more at www.indianahistory.org <http://www.indianahistory.org/>. I was driving the other day... my friend looked over and said, 'You're going 80!.... I said, 'So are you!' --Hank McGill ...and so it goes... ...><((((>`...><((((>`...><((((> Reply to Sender : https://community.culturalheritage.org/eGroups/PostReply/?GroupId=481&SenderKey=ec324446-e16d-4d75-9c30-00000573537d&MID=9116&MDATE=756%253e46546%253c&UserKey=d16eaa87-0f69-494b-9f2f-303dbc1222e1&sKey=fab9aa4f27a04c5d876e Reply to Discussion : https://community.culturalheritage.org/eGroups/PostReply/?GroupId=481&MID=9116&MDATE=756%253e46546%253c&UserKey=d16eaa87-0f69-494b-9f2f-303dbc1222e1&sKey=fab9aa4f27a04c5d876e You are subscribed to "Global Conservation Forum (ConsDistList)" as [email protected]. To change your subscriptions, go to http://community.culturalheritage.org/preferences?section=Subscriptions&MDATE=756%253e46546%253c&UserKey=d16eaa87-0f69-494b-9f2f-303dbc1222e1&sKey=fab9aa4f27a04c5d876e. To unsubscribe from this community discussion, go to http://community.culturalheritage.org/HigherLogic/eGroups/Unsubscribe.aspx?UserKey=d16eaa87-0f69-494b-9f2f-303dbc1222e1&sKey=fab9aa4f27a04c5d876e&GroupKey=757a8f16-505f-4323-8e74-e376757aa9f7.
