For those who have never heard of Vinegar Syndrome as a malady in model horses, let me be the first to assure you that once you are introduced to its existence, it can completely change your life as a model horse enthusiast, whether simply a collector, or a live or photo shower. More commonly referred to in the model horse community as "oozies" or "shrinkies", the Vinegar Syndrome-infected model is likely past repair, and, more frightening still, contagious to other models. Yes: I said contagious! Although this sounds like something out of science fiction, or, at the very least,the warped mind of someone who has spent a little too much time around their "toy horses", it is a very real malady, and it can, if unchecked, wipe out your entire collection in a matter of days or weeks.
Model horse enthusiasts first noticed "oozies/shrinkies" in the batch of horses created by Breyer dating from 1987-the early 1990s. My own introduction to the malady came courtesy of a Sears Special Run Performance Horse who came in a set of three horses (with a grulla leopard Stud Spider, known here at Mythic Stone Stables as Mythic Stone, and a palomino lacy blanket with spots Running Stallion, known here at Mythic Stone Stables as Zeus' Treasured Sun) in 1990. He was featured in the Sears Wishbook that year, and was one of the first in a long string of horses purchased for me by my husband. Shown and pedigreed as Lucky Spider, he had been past the point of showing for a number of years, due to the oddities that were developing in his legs (please see photos throughout this page). Though he had never been exposed to extreme temperatures (I practice careful climate control with all of my models), he had spent a few years in a box in storage, and I thought this was the source of his odd leg issues. That is, until he began to "sweat".
As you can see from the photos on this page, my Sears Special Run Performance Horse from 1990 (henceforth mentioned in this page as Lucky Spider) developed a strange "ooze", particularly on his head, but also elsewhere on his body, that looks very much like sweat or a thin layer of condensed water. However, don't let the look of it fool you: the liquid in question also wreaks of vinegar.
In a panic, I went to my favorite model horse list (IPABRA), and began to ask questions as to whether anyone else had ever experienced this "weeping Madonna" effect with their model horses. This was the point that I discovered I was not alone, and that the horses most heavily associated with becoming "oozies" were those dating from 1987-the early 1990s. This was also the point at which I was introduced to the contagion factor.
My immediate reaction was to call Breyer (Reeves International, located in New Jersey), at which point I was informed by the very helpful customer service representative with whom I spoke that Breyer had no previous knowledge of this issue, and asked to send photographs of the "infected" horse to them. I did so. And then I began to do my own research....
Breyer model horses are made of cellulose acetate--the same substance of which Kodak film, used in the movie industry, is made. I am sure anyone who has ever watched the Academy Awards has heard the talk of film degradation, and the necessity of stopping it, particularly where old films are concerned, before it is too late and we lose our "movie heritage". The film degradation of which these people are speaking is actually called cellulose triacetate degradation, or, more commonly, Vinegar Syndrome. This is the same malady which is affecting Breyer horses, and causing "oozies/shrinkies".
The first incidents of Vinegar Syndrome in film were reported in 1948, within a decade of the introduction of cellulose acetate film. This first report came out of India, where film was stored under very hot and humid conditions. Beginning in the 1980s, there was a renewed and greater focus upon the study of film stability by Eastman Kodak, which resulted in the discovery that cellulose triacetate degradation results in the secretion of acetic acid and the shrinkage of film. Acetic acid is the key ingredient in vinegar, and this is how cellulose triacetate degradation became known as Vinegar Syndrome.
The scent of vinegar (the smell of the "secreted" acetic acid) is the first indication of cellulose triacetate degradation. Initially, the acid is only secreted within the plastic itself, but as it gradually diffuses to the surface, this leads to the acidic smell. It is believed that the degradation's start is caused by exposure to moisture, heat, or acids. Keeping the item made of cellulose acetate in an area with poor ventilation can also cause the degradation to begin. Something used in the chemical process of cleaning them causes Disney films to be especially likely to develop Vinegar Syndrome, likely because this cleaning process actually seals the film, so that it does not receive the proper ventilation previously mentioned and, essentially, collapses in on itself due to cellulose triacetate degradation.
This last morsel about Disney films, and their prevalence to develop Vinegar Syndrome, may suggest a clue as to why Breyer horses made between 1987-the early 1990s are more predisposed to becoming "oozies/shrinkies". It is possible--although as yet unverified--that Breyer may have used a different sealant on their horses during this time period, increasing the risk of them developing cellulose triacetate degradation. I have also noted that horses which do not have the usual ventilation hole (usually found inside one of the nostrils on most Breyer horses) are more prone to develop the malady. Living in the South, controlling humidity where model horses are concerned is largely a losing battle, and this may also play a factor. (It would be interesting to take a survey of how many of the horses reported as "oozies" in the model horse world are from the more humid areas of the United States and the world.)
An exhaustive list of the symptoms of cellulose triacetate degradation includes (first described in film, and then as exhibited in model horses): the release of acetic acid creates a wet sheen and a vinegar smell (same with both film and model horses); film becomes brittle (model horses break more easily) due to the break off of cellulose acetate polymers (this occurs in the later stages of degradation); shrinkage (can be by as much as 10%, both in film and in model horses); buckling (this can be seen in the model exhibited on this page, particularly on his rear legs) caused by the fact that as the acetate base shrinks, the gelatin emulsifiers used in its creation do not, because they are not undergoing deterioration; formation of crystalline deposits or liquid-filled bubbles (often found on the belly of the model horse in question, as I discovered with Blue Jackal Arabians' Hadban Hathor--I apologize for the lack of pictures--these appear as small, round circles, approximately dime-sized, or perhaps smaller, circled by a shiny ring of liquid-appearing or glossy substance) which are evidence of plasticizers, additives to the plastic base, becoming incompatible with the cellulose acetate and oozing to the surface (also a sign of advanced degradation); pink or blue colors appearing on the surface of the cellulose acetate (although I have not seen this exhibited in my own models--thank goodness!--I have read reports of discolorations beneath the normal overpaint on some models from the era in question, particularly between the ears, when the model has been bleached for customizing) caused by antihalation dyes, which are normally colorless and incorporated into the gelatin layer when manufacturing cellulose acetate.
As if it isn't bad enough that we can literally watch a favorite model "decompose" before our very eyes, Vinegar Syndrome is also, as I previously mentioned, contagious. This is the area of discussion where this malady, so common in cellulose acetate film, starts to sound like something out of a bad science fiction novel, particularly as it pertains to model horses. Generally speaking, when we think of something being a contagion, we think of bacteria, fungus, or viruses which cause said contagion. However, in this case, we are not talking about a disease (although it can certainly feel like it once you find an infected horse in your model herd!), but a chemical reaction. While there are, in fact, bacteria which do, indeed, eat plastic, that is not what is responsible for this form of degradation. Instead, it is the fumes from the acetic acid caused by the process of cellulose triacetate degradation which lead to the contagion factor with Vinegar Syndrome.
In 1991, The Association of Moving Image Archivists performed a scientific test to determine the factors leading to contagion of cellulose triacetate degradation in film. Via this test, it was determined that it was only the catalyst (or accelerator) for the degradation which is infectious, and not the root cause of the deterioration (humidity, heat, etc.). From this test, they concluded that there was ample evidence that acetate film and base will absorb acetic acid vapors from the air, which results in an acceleration of the deterioration process.
It is this absorption of the acetic acid fumes which causes the contagion factor of cellulose triacetate degradation (Vinegar Syndrome) in model horses. This contagion factor, however, makes the situation far more of a crisis, when one considers that, via exposure to said fumes, models made in other time periods other than 1987-the early 1990s can become "infected" with Vinegar Syndrome due to exposure to "infected" model horses. In other words, these model horses do not have to come into physical contact with the "infected" horse to become "infected" themselves, but merely be placed in close enough proximity to be exposed to the fumes--whether that means being kept in the same china cabinet/display case, or being wrapped and kept in the same box for travel/storage.
Under normal circumstances, cellulose acetate has a life expectancy of around 500 years. However, once "infected" with Vinegar Syndrome, items made out of this substance tend to break down fairly quickly. So what can we do, once our model horse herd has been exposed to this dreadful malady, to attempt to insure that they will out-survive us on this planet?
The first order of business is to quarantine any "infected" models, so that they cannot further spread the catalyst that causes Vinegar Syndrome. This means taking these models completely out of proximity to the rest of your collection, inclusive of storage in seemingly-well-ventilated china cabinets/display cabinets. The models in question should also be left unwrapped, as sealing them away from the air can lead to further degradation (therefore, speed up the process of cellulose triacetate degradation). Studies pertaining to the preservation of cellulose acetate film suggest that the use of activated charcoal filters in the area where Vinegar Syndrome-affected films are kept can considerably slow the process of contamination; that being the case, in dire cases, placing the model in an un-water-filled aquarium with a charcoal filter might also mitigate the situation, while at the same time acting as a new sort of glass display case. This same study has also suggested that exposing "infected" film to subfreezing or extremely cold storage temperatures can postpone further decay. In desparation, I have conducted experiments of my own concerning this last method on Lucky Spider: first, I thoroughly cleaned the model of all acetic acid residue using room temperature tap water, and thoroughly dried the model; I then placed him in the freezer for two hours on Saturday night (9-11-2010), followed by a slow-thaw period in the refrigerator. It is now Monday, 9-13-2010, and the model in question no longer exhibits any ongoing symptoms of Vinegar Syndrome. I am repeating this process with Blue Jackal Arabians' Hadban Hathor. No damage is sustained to models by placing them in the freezer, so long as the thawing process afterwards is heavily controlled and very slow. Thus far, I definitely recommend this as a method for curtailing Vinegar Syndrome. However, it is important to note that the "infected" models should still be maintained away from the rest of one's herd, just to be on the safe side.
It is best to maintain all models (particularly those produced in the years in question) in a cool, dry, heavily ventilated location, rather than maintaining them wrapped in bubblewrap in boxes, whether the area in which you live is prone to high temperatures and high humidity, or not. Those without apparent "personal ventilation" (the Breyer "air holes" in the nostrils) should be particularly watched for development of this "disorder". Also, it is not recommended that any model that is "infected", or could potentially exhibit signs of this malady in future (those made between 1987-the early 1990s), be customized, as the spraying of any sealant on the model in question could further act as a catalyst for degradation, due to it sealing the acetic acid in on itself (basically leading to an "imploding" horse).
If I should hear more from Breyer considering this "condition", I will further update this page. However, in the interrum, please feel free to pass this link on to others within the hobby, as a means of education and prevention.