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Most microfilm produced prior to 1980 has a base made of cellulose acetate, which is subject to a special kind of degradation known as the “vinegar syndrome.” As microfilm ages and begins to deteriorate, which is especially affected by heat and humidity, acetic acid is released, further speeding up the deterioration process and resulting in a vinegary smell. As the syndrome develops, microfilm will distort, become brittle, and eventually become unusable as it separates between the emulsion and base layers. The vinegar syndrome is a looming and serious threat to practically all large microfilm collections. This program will provide information on how and why the vinegar syndrome develops in a microfilm collection, how one can test for the syndrome, and what options or solutions are available. The program will also highlight the problems confronting UNC Greensboro, as it deals with an outbreak of vinegar syndrome discovered in September 2010.
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The Vinegar SyndromeThe Vinegar Syndrome
A Death Threat to the Microfilm A Death Threat to the Microfilm CollectionCollection
Stephen DewStephen Dew
Collections & Scholarly Resources Collections & Scholarly Resources CoordinatorCoordinator
UNCG LibrariesUNCG Libraries
Microfilm Made with Two Microfilm Made with Two LayersLayers
Liverpool optician Benjamin Dancer Liverpool optician Benjamin Dancer developed the process for microfilm in developed the process for microfilm in 18521852 The The emulsion layeremulsion layer is the layer that actually is the layer that actually
contains the image. This side has acontains the image. This side has a matte matte-like -like appearanceappearance
The The base layerbase layer is the transparent, supporting layer is the transparent, supporting layer to which the emulsion layer is adheredto which the emulsion layer is adhered
Essentially the same process later used for Essentially the same process later used for microfilm, motion picture film, and reel-to-reel audio microfilm, motion picture film, and reel-to-reel audio filmfilm
Nitrate Microfilm, 1920-Nitrate Microfilm, 1920-1930s1930s
For early microfilm, the base layer was made of cellulose nitrate
Unfortunately, cellulose nitrate proved to be unstable, and in the presence of moisture, heat, and acids, strands in the presence of moisture, heat, and acids, strands of cellulose nitrate tend to become detached, liberating of cellulose nitrate tend to become detached, liberating nitro groups (nitro groups (one or more groups of NO2 ions)
Nitro groups are harmful substances; they are strongly Nitro groups are harmful substances; they are strongly acidic and strongly oxidizing in nature.acidic and strongly oxidizing in nature.
Nitrate film, especially if deteriorating, is a fire hazard
Acetate Microfilm, 1923-Acetate Microfilm, 1923-1980s1980s
Cellulose triacetate was used as the base layer for Cellulose triacetate was used as the base layer for microfilm between 1923 and 1980smicrofilm between 1923 and 1980s
Acetate film was originally thought to be highly stable
Since it could not degenerate to form nitro groups, it was termed “safety film”
Transition from nitrate to acetate film lasted from 1930 to 1950
Unfortunately, acetate film proved to be just as unstable as nitrate, but not as toxic
Polyester Microfilm, Polyester Microfilm, 1970-Present1970-Present
Most current microfilm uses polyester Most current microfilm uses polyester for the base layerfor the base layer
Polyester if very stable and has a 500 Polyester if very stable and has a 500 year expected lifespanyear expected lifespan
Nitrate & Acetate film have a 100 year Nitrate & Acetate film have a 100 year lifespanlifespan
Vinegar Syndrome
Vinegar syndrome is a slow form of chemical decay that causes cellulose acetate film base to shrink, warp, curl, and become brittle.
Long strands of cellulose triacetate react with water to form cellulose diacetate and acetic acid
Vinegar is a 5% solution of acetic acid in water, and acetic acid is what gives vinegar its smell
This decay is inevitable.
Acetic Acid Speeds Up Acetic Acid Speeds Up DegenerationDegeneration
Cellulose triacetate microfilm is prone to Cellulose triacetate microfilm is prone to degenerate and is especially sensitive to degenerate and is especially sensitive to temperature and humiditytemperature and humidity
Acetic acid is a product of the reaction of Acetic acid is a product of the reaction of acetate and water acetate and water
Acetic acid is a catalyst for the reaction, Acetic acid is a catalyst for the reaction, speeding up the degeneration processspeeding up the degeneration process
Eventually, the process feeds on itself and Eventually, the process feeds on itself and becomes “autocatalytic”becomes “autocatalytic”
UNCG Discovers Vinegar UNCG Discovers Vinegar SyndromeSyndrome
Early September 2010, students re-shelving Early September 2010, students re-shelving microfilm reported a strong smell of microfilm reported a strong smell of “pickles” or “vinegar” in the microfilm “pickles” or “vinegar” in the microfilm cabinets that contained old issues of the cabinets that contained old issues of the New York TimesNew York Times..
Michael Ingram, supervisor of the students, Michael Ingram, supervisor of the students, investigated and confirmed the smellinvestigated and confirmed the smell
He googled “microfilm and vinegar,” and he He googled “microfilm and vinegar,” and he discovered a number of webpages discovered a number of webpages concerning “vinegar syndrome”concerning “vinegar syndrome”
UNCG Discovers Vinegar UNCG Discovers Vinegar SyndromeSyndrome
Ingram discovered Website for the Image Ingram discovered Website for the Image Performance Institute (IPI), producer of “A-Performance Institute (IPI), producer of “A-D Strips: Film Base Deterioration Monitors”D Strips: Film Base Deterioration Monitors”
Ingram informed, the Head of Reference, Ingram informed, the Head of Reference, the Collections Coordinator, and the the Collections Coordinator, and the Assistant Dean for Collections & Technical Assistant Dean for Collections & Technical ServicesServices
They approved the purchase of A-D Strips They approved the purchase of A-D Strips for testing individual rolls of microfilm (250 for testing individual rolls of microfilm (250 strips per package for $60)strips per package for $60)
UNCG Discovers Vinegar UNCG Discovers Vinegar SyndromeSyndrome
Late September 2011, testing process began on Late September 2011, testing process began on New York TimesNew York Times, 1930-1940, where the smell was , 1930-1940, where the smell was strongstrong
Students discovered the vinegar smell in other Students discovered the vinegar smell in other cabinets, and testing expanded to the cabinets, and testing expanded to the Greensboro Greensboro Daily RecordDaily Record, the , the Raleigh News & ObserverRaleigh News & Observer, and , and the the CarolinianCarolinian
Testing process was slow, taking about 50 rolls at Testing process was slow, taking about 50 rolls at a time for each title and focusing on 1920-1980a time for each title and focusing on 1920-1980
By July 2011, about 1,000 rolls had tested positiveBy July 2011, about 1,000 rolls had tested positive
Acetic Acid as IrritantAcetic Acid as Irritant
Dilute concentrations of acetic acid are safe. vinegar contains about five percent (5%) by mass and this is generally harmless.
At higher concentrations, at least ten percent (10%), acetic acid becomes an irritant. It can be an eye irritant, inducing secretion of tears, and it can be a skin irritant, causing discoloration and itching
Limited Storage Conditions at Limited Storage Conditions at UNCGUNCG
Jackson Library Basement, 73 F, 43% Jackson Library Basement, 73 F, 43% RHRH
Ferguson Remote Storage, 69 F, 39% Ferguson Remote Storage, 69 F, 39% RHRH
Rolls Replaced, Stored, & Rolls Replaced, Stored, & DiscardedDiscarded
CarolinianCarolinian rolls have been replaced and will rolls have been replaced and will be digitized (digitization project)be digitized (digitization project)
New York Times, New York Times, sincesince available online, available online, rolls are being withdrawn and discardedrolls are being withdrawn and discarded
Greensboro Daily News Greensboro Daily News and and Raleigh News Raleigh News & Observer& Observer Stages 1 and 2 going to storage, stage 3 Stages 1 and 2 going to storage, stage 3
discardeddiscarded Patrons referred to Greensboro Public LibraryPatrons referred to Greensboro Public Library Replacements will be $12/roll from State LibraryReplacements will be $12/roll from State Library
Vinegar Syndrome at Vinegar Syndrome at UNCGUNCG
Testing will continue on Testing will continue on NYTNYT and and RN&ORN&O
With large collection of cellulose With large collection of cellulose triacetate microfilm and less-than-triacetate microfilm and less-than-ideal storage, UNCG can expect to ideal storage, UNCG can expect to discover more rolls and titles discover more rolls and titles affected by the vinegar syndromeaffected by the vinegar syndrome
If you own Triacetate MicrofilmIf you own Triacetate Microfilm
This Is a Warning!This Is a Warning!
The Vinegar Syndrome Is The Vinegar Syndrome Is Inevitable Inevitable
And It Will Be Visiting a Library Near And It Will Be Visiting a Library Near You -- SOONYou -- SOON
