 Kristen, go right ahead. Thank you, Susan. Welcome, everyone. As Susan mentioned, I'm Kristen Lays. I work here at Heritage Preservation, and we're very glad that you've joined us today. Looks like a lot of you have been on our previous webinars and live chats, and we appreciate you joining us again. We are recording this today, so I just want to give our little description so that others who might be listening to the recording later understand what this is about. But Heritage Preservation is moderating the Connecting to Collections online community in cooperation with the American Association for State and Local History and with funding from the Institute of Museum and Library Services. We are very grateful to Learning Times for helping us design our online community site and for producing these live chats. And what we're doing with this online community is hopefully building a network of museums, libraries, archives, and historical societies, especially those that are smaller and don't have a conservator on staff, and creating a place online where they can get reliable preservation information and can network with their colleagues. And this last week in particular, it's been really great to see our discussions being so active on the site. We have developed this community as another outreach after the Connecting to Collections initiative bookshelf and raising the bar workshop and webinars and other seminars and workshops that we've done around the country. And so it's also a place where we've had all those recordings archived and again just a ready resource for everyone. We are up to almost 1,500 members on the online community and that's just great. So about twice a month we do these webinars and at the end of today's session I will talk about some that are upcoming. Today we're going to be talking about the care of plastics and on the online community you'll see a link to our resource that we're featuring. And we have two great speakers with us today, Christine Furnart, a conservative contemporary art and modern materials in New York City and Odile Madden who is a research scientist at the Museum Conservation Institute at the Smithsonian Institution. And they have a lot of great information for you today. But I just want to remind everybody that if you do have questions that go beyond what we're able to cover in today's webinar, just know about the American Institute for Conservation of Historic and Artistic Works. And on their website they have this find a conservator link and that's a place that you can search by type of material and geographic location to find someone in your area that could help you with more specific issues. Before we get going, I just want to learn a little bit more about our audience today. If you don't mind answering a few poll questions, it'll help set the stage for what we're trying to learn. Would you mind just typing in what institution you're joining us for, like a museum, library archive, historical society, historic site? I think we've done this as a multiple choice close-ended question. And there's just such a variety that it's sometimes nice to see an open-ended response. You're seeing some nice diversity here. Just a few more minutes to make sure everybody has a chance to reply. We've got about 50 people so far on the chat today. We're going to have another open-ended question. I'm going to just sort of describe what types of artifacts you have in your collection that are made of plastics. You may have a large variety. So if you prefer, you can also answer the question in terms of what are the plastic objects in your collection that you're most worried about? What brought you here today? Again, it looks like a great variety of household items. And we've heard about Diane Vole and her vintage traffic cones, hard hats, things used by road designers and construction workers. Very unique collection. Just a few more minutes. OK. Next is a close-ended poll question. All right. It looks like Christina O'Deal helped her work cut out for them in terms of giving you some tips on storage. And finally, I want to see what types of preventive measures you are engaged in in terms of, excuse me, let me just resize this box, into how do you inspect your plastic materials for degradation? All right. Well, we'll have some tips for you today for sure. OK. Well, I just want to let you know there's some talk about not hearing, voice talking. And I was just getting everyone a chance to fill in these poll questions. And I was being apologize if I have made you concerned about your audio, but we are off and running now. I'm going to go ahead and close these polls. And we'll go ahead with Christina O'Deal's presentation. And while I bring that up, I'll just invite them to say hello and tell us a little bit more about themselves. Hi, this is O'Deal Madden. I'm a research scientist at the Smithsonian's Museum Conservation Institute. And I want to say thanks to Heritage Preservation for having us here today to speak to you about plastic. I am a research scientist who was originally trained as an objects conservator. So I have familiarity with the issues of people working with collections based. And I am the head of the modern materials research group at MCI. So we tend to focus on plastics, but we also look at other materials, high-tech metal alloys, nano stuff, and the like. But I like to focus on plastics because I think they're our biggest conservation challenge. Hi, and I'm Christina Fronert. I'm a conservator for contemporary art, modern materials, and media. I'm done just in the process of founding a company with a colleague, big and Fronert, entirely focusing on contemporary art and modern materials and media. And I'm a traditionally trained Paintings and Sculpture Conservator at Joint Museum Ludwig and Cologne in 1993 and became head of conservation of the department in 2000. And we were looking at the media collection in the museum, which houses a large film and video collection, as well as the plastic collection. And this is when a program became available in Bern, Switzerland. So I went there and graduated from there too and ever since. Both media and modern materials are my passion. Well, great. Thank you, and welcome again. We appreciate you joining us. I'll turn it over to you to start your PowerPoint. And then we'll answer questions as we have time to in the middle of your presentation. But everyone, feel free to ask questions in the chat. And I will look for those. And we will make sure they get answered, if not right away at some point during our hour together. Great. Well, this is Odile, and I'm going to start the presentation. And Christina is going to do the second half for calling us the care of plastics. And we're going to be talking about plastics in collections and discussing considerations and caring for them. This is going to be fairly broad and general, as we have limited time today. And we want to make a lot of time for you guys to ask your questions. So I think it's always useful to have an idea of where we're going. So here's the plan of what we're going to follow. We're going to try to stick to. First, we're going to be defining plastics, what we mean by them. So we're all talking about the same thing. We're going to cover how we identify and characterize them and how you might as well. We're going to discuss signs of deterioration, what that deterioration looks like or smells like. Then we're going to talk about the causes of deterioration. And this is going to be fairly cursory. And then we're going to be making some recommendations for monitoring storage, exhibit, cleaning, repair, et cetera. And we're going to try to stick roughly to this outline. You'll see some of that information gets interspersed in what we're talking about. Some recommendations might come up much earlier than in their place in the presentation. So let's talk first about what plastics are. What do we mean by them? I like to call them polymer composites. Plastics are a broad category of materials, the fundamental unit of which is called a polymer. And these polymers tend to be mixed with plasticizers, colorants, or pacifiers, fillers and bulking agents, fire retardants, UV stabilizers, and other materials that either modify the way the material is processed, so the way the polymer is they cast into a film, or something that will modify the performance of the polymer, so making it very flexible as opposed to rigid. And so it's a classic for a common name for polymer composite materials, as I just said. The fundamental component is a polymer. And a polymer is a long chain molecule, usually as a carbon backbone, sometimes silicon. And I'm going to show you a picture of a really straightforward polymer, polyethylene. The gray balls are carbon atoms, and the white balls are hydrogen atoms. And I promise this is very interesting and will be mercifully brief. But each one of these three chains is what we would call a polymer. It's a molecule that can have a number of carbons ranging from thousands to hundreds of thousands in length. The material properties of the polymer, what makes a plastic have certain properties, depends on the kinds of the atoms present and how they're arranged. I'm going to show you two other examples. The one at the top is polyethylene teraphthalate, which we call PET. It's the main component in your soda bottles. And you can see that it's got the gray carbon, the white hydrogen, and it's got some red oxygen atoms as well. And you can see that it has their lengths of carbon, but it's interspersed with oxygen, and there are rings. That's going to affect how that material behaves, for one thing, making it react differently to water than, say, polyethylene would. Then below that is cellulose. Cellulose is a natural polymer. The structural polymer are found in all plant materials, so in wood and linen. It's really what makes your paper fibers, your cotton fibers. And you can see that it's a really elegant structure made by nature. Beautiful five-membered carbon ring with an oxygen in there. And this natural polymer, you all are familiar with it from working with paper. When we talk about semi-synthetic plastics, you'll hear a lot about the true synthetics and the semi-synthetic. The semi-synthetic, I want to point out, tend to refer to these natural polymers that have been modified. The carbon backbone already exists, and the end groups are modified. So hold on, I'm going to try to pull up a pointer here. This webinar technology is amazing. This is our polymer backbone, and these are our side groups. So when you've got cellulose nitrate or cellulose acetate plastics, what's happening is that these end groups are being replaced out, OHs are being replaced out with nitrate groups or acetate groups. And that really changes how the material behaves. All of a sudden, something like paper can be dissolved in a solvent like acetone, or it can be heated and made to flow. And those are things that do not happen with paper. Make the pointer go away. No. On. There we go. So polymers are just, a plastic is a polymer composite. That's really important to remember, because polymers on their own are often not useful. So they tend to be mixed with smaller molecules that will change the properties of the final plastic material. And let me give you some examples of what those might be. Oh, I'm going to give you some right now, and then we'll see you with a couple in another minute. The molecules might be colorant. They could be something that makes the material opaque rather than transparent. They might be decorative. The molecules called plasticizers are also ones that affect the flow of your polymer. So your polymer might not be able to be melted at a temperature of the processing equipment that a factory has. But if you add a plasticizer molecule, these little molecules act sort of like ball bearings between the polymer chains and allow flip to happen more easily so the polymer can be melted at a lower temperature. So how do we go about identifying and characterizing these plastics? I'm at the Smithsonian, and I like being there because I have this suite of analytical instrumentation. So we use, I tend to rely on non-destructive, non-sampling technologies like Raman spectroscopy, infrared spectroscopy, X-ray fluorescence spectroscopies, and those will tell us what molecules we've got and what elements are present. Then there's also GCMS, gas chromatography mass spec, which requires a sample to be removed, but that can be very useful analytically. But not everyone has that instrumentation. I mean, it's hundreds of thousands of dollars to maintain a lab like that. So most of the time, we're looking at plastics for visual cues. The most obvious is the resin codes that are on the underside of many plastic objects, many containers. So when you see the triangle with the arrows, it says PP for polypropylene or HDPE for high-density polyethylene. Those give you the idea of the polymer that's there. They don't tell you what additives are there. And they're there for helping to sort recycling. They're not there for us working in the preservation field, but they can be helpful. Then the look of a material. What does the plastic look like with time you might get used to recognizing what the polypropylene looks like? And we don't have the time or the resources to be able to show you that today. That really comes with experience. But I'd say that it's not just about identifying what polymer you've got. The plastic, as I said, it's polymer plus additives, then it's processed into a form. So you want to know, have you got a clear film? Do you have a foam? Do you have a solid block of plastic? Do you have a coating? Do you have a fiber? Those are visual cues that are very important to record, and we'll consider how you go about caring about something. Smell, for those of you who deal with some of the smellier plastics, like cellulose acetate, smells like vinegar, rubber has a very characteristic smell. So you can smell the artifact itself, or there are also melt burn tests, which I don't advocate for melting artifacts and doing. That's a destructive test. But if you have the opportunity to make one, make some smoke, you try to give it a quick whiff and see if you can recognize it. The density of plastics will help tell you some float and some don't float, say in water. If you have that opportunity, you could look at it. But basically, density means the weight of the object compared to how big it is. And then the solubilities, that they're the thermoplastic polymers that tend to be soluble in some range of organic solvents. And then there are the thermostat plastics, which tend not to be soluble. So sometimes that can help you narrow down what you're working with. Let's have just some looks. This is a, we're going to see this object a couple of times. This is something called Lumeras. It was a brand of cellulose acetate made by the Celluloid Corporation, which then became the Celemies Corporation. And it was a plastic that replaced cellulose nitrate. And cellulose acetate was really popular because it could be injection molded and also because it could be made in amazing colors. So what we have here in the middle is a salesman's kit of coupons. So these are square coupons. You see one in the upper right. And these would have been brought to a customer to say, hey, you want to make eyeglass frames, look what you can make eyeglass frames look like. And the properties that you might do some quick properties, you'd see that there are colorants that have been added. So you're looking at the color of an eye object will give you some idea of what's in it. The opacifier, some of these are transparent. Some of those are opaque. So you'd say, OK, there's something and I was making it opaque. Glitter is even in one. It's actually in this one right here. It's pretty fabulous. It's like a ruby red with glitter. And plasticizers. This is important to deal with a step in learning to deal with plastics is understanding the technology by which they're made. And that takes time. So I happen to know working with cellulose acetate an awful lot that it cannot be injection molded and made to flow for any purpose without a plasticizer being added. So I know to look for it. And commonly, that plasticizer is diethyl phthalate or dimethyl phthalate. And you often see triphenyl phosphate as well. But that's something I now know through years of experience. So Christina is going to talk about the causes of deterioration. But since I'm going to be showing you some deterioration, I'm going to give you a quick rundown of their causes that are external to the artifact, such as mechanical damage, dingy hit, temperature, humidity, light, pollutants, and biological organisms. And then there are internal causes of deterioration, which sometimes conservators refer to as inherent vice. That can be caused by chemical instability. So the polymer is just inherently unstable. Incompatibility of components. Sometimes that plasticizer isn't well matched to that polymer. Or as the polymer ages, the plasticizer doesn't a good fit anymore, and it tends to migrate out. There can be contaminants from the manufacturing process. And there can be defects in internal stresses, which comes from processing. So let's say you injection mold a plastic, which means that you take a molding powder of the plastic, you heat it up, it flows, you squirt it into a mold, you cool down that mold and out comes your object. Internal stresses can be set up when that polymer hasn't had enough time to relax. And those can cause problems over time. They can cause explosive breakage. They can cause chemical reactions to happen more in that location. Because that point where there is stress, there is higher energy. It's more likely to do stuff. What are signs of deterioration in plastics? I divide them into those that are visible, smell, have to do with weight, mechanical changes, and unseen chemical changes. Mechanical changes and unseen chemical changes, you're not going to see so much. You might feel a mechanical change, say, for a film that just doesn't feel as flexible anymore. Something that feels brittle. So let's go through some examples. Discoloration. These are two spray bottles that belong to my hairdresser, Joanne, in Los Angeles. He's a good friend of mine. And after 10 years of going to him, he's had this plastic duck, the one on the left. And over time, it started out as all one color. But it's made of a bunch of different plastic materials, right? There's the head. And then there's the body. And then there's this water plug. And then there's this squirt bottle attachment. And then there's a white neck. Over time, these have become different colors. And we suspect that light exposure is the culprit. You can see this one is newer. And already, it's got differences as well. So this is easier to notice when you've got a plastic object with multiple pieces on it. Or you might be able to see differential exposure, like if you had something that the top side might be more faded than the underside. But sometimes, it can be a little difficult to keep track of if an object's fading overall. In which case, monitoring is really useful. Because you want to have an idea. You'll forget over time what color the thing was. You want to record it. There we go. So other visible signs of degradation, looking at the luminous coupons. Here we had, there were 46 of these coupons. They belong to the National Museum of American History, which is a Smithsonian Museum in Washington. These coupons are cellulose acetate. They all should have been breaking down. But we found instead that 46 were in good condition and three were severely deteriorated. And cellulose acetates are notoriously unstable plastic. And we were interested that only three were showing the severe deterioration. And without going into the cause, I will show you some of the characteristics. First thing we saw was liquid plasticizer, which is diethyl phthalate exuding from the cellulose acetate. So you can see the arrow pointing to those little droplets of liquid. And it's actually moving as a front that moves out across the stable object and is followed by cracking. You can also see that brown discoloration up in the worst in the most degraded areas. The loss of diethyl phthalate, triphenyl phosphate and acetic acid. And those are all things we figured out, except for the acetic acid, we figured out all those things instrumentally. So that's not something you'd be expected to be able to see in a chemical. But if you know what the, if you understand cellulose acetate technology and you understand something about how it falls apart, which you learn with experience, you'll have an idea of what those compounds are. So we've got, what happens is the plasticizers and acetic acid are lost and that means the material shrinks, right? And shrinking can be manifested as distortion, the formation of a waste. So this would have had flat sides originally and eventually cracking as the material tries to accommodate that loss of its bulk. Another sign, another instance of distortion here. This is something from the resin kit, which some of you might be familiar with, it's a reference sample, they're reference samples of plastics provided to industry. You can see here, love this pointer. You can see here, this would have been originally in plain. So with time with the loss of plasticizer, it's distorting. Smell is a good indicator for deterioration. And certainly we don't advocate that you go sniffing noxious chemical compounds, but when you're working with plastics, often the smell is obvious. So the smells that are emitted by artifacts are signs of deterioration often. So smelly plastic and rubber may indicate loss of volatile acids, plasticizers or other substances. So that shrinkage phenomenon's happening even if you can't see it yet. Big examples are plastics that evolve acids might smell like vinegar or vomit. Those would be indicative of cellulose acetate, which gives off acetic acid, which is vinegar. Or vomit is often cellulose acetate butyrate, butyric acid smells like vomit. Camper could indicate cellulose nitrate. So use your nose. Pay attention to the smells in your storage areas. And here, weight loss is another one. It's very simple. When you're doing monitoring, weigh your objects, especially if they're a solid thing that's not shedding components. These are the Lumarth coupons, the 49 coupons. You can see that this shows a graph of the y-axis as their weight, and the x-axis is the number of the coupon. And you can see that these 46 all weigh about the same. And the three deteriorated ones weigh 20% to 30% less. And that goes a long way to explaining why that cracking is happening. And with that, I will turn it over to Christina. Thank you, Odeal. Yes, as Odeal already mentioned, there are various influencing factors as shown in this graph that are responsible for the degradation of polymers. It is hard to focus the reactions because the different degradation agents interact and practice. And in addition, in most of the cases, no information is available about the possible irregular constitutions of the molecules. Another widely unknown factor is the blend or compound or impurities and additives. So this is resulting in visible change of the material like discoloration, change of dimensions, embrittlement, crumbling, loss-of-surface gloss, and mechanical properties. And a more extreme condition is the release of voluntary products that can be found on the surface. Yes, arrow. So let's look at more damage phenomena in more detail. Here are some examples of degradation phenomena found while conducting and monitoring at the Museum Ludwig and Cologne in Germany. And to the left, you see a well-known damage for PMMA, or better known as FACCI, which is grazing. And grazing occurs as a network of microfissures that are apparent fishes are internally bridged by a polymer material of lower density. And it can be found due to internal or external stress, chemical agents, or a loss-of-surface synthesizer. You can also find it in cellulose nitrate and PMMA. And a surprising example was seen on the right. And this is the glazing of a frame that was affected by powder particles. And as you can see, the insects weren't stopped by the plexiglas glazing to find their way out of the framing. I initially couldn't believe my eyes when I saw it. But it is widely known that plastics can be attacked by micro-organism and macro-organism. And it's seen within polyethylene, polycarbonate, PMMA, PVC, polyurethane. Liquid deposits on polymers have been found on the surface of this artwork. And this is usually due to the migration of the pesticides, degradation parts, products, or lubricant deposits. If you encounter it, if you see liquid deposits on artworks, don't touch them. But as Odile already mentioned, check the endure. It might point you to the polymer that you're looking at. It can be found within cellulose, nitrate, cellulose, acetate, PVC, and polyurethane. This is, of course, an extreme example and shows how artwork made out of polyester by Duane Hansen was severely damaged by a visitor through a very, very strong mechanical interaction. It was basically a schoolboy running into it. And the impact was that hard that even the weight was secured to the wall, was pulled out of the wall and resulted in this severe break of the arm. Crumbling is an active degradation of polymer resulting into micro fragments. And so it's often triggered by the influence of oxygen and ozone, as well as, well, higher temperatures and the exposure to light, which results into the decisions of the, in chain decisions, as seen to the right on polyurethane, and which is the most prominent polymer that shows this kind of degradation. Monitoring of your plexiglassic collection is a powerful tool to determine the condition and the needs of the object in your collection. And in order to plan a project like that, you are wanted to specify and determine the scope of your examination of your objects. It is always helpful to conduct a pilot survey or pilot monitoring to identify the variety of your objects in your collection and also to quantify the project. Once you have the results from your pilot survey, you can analyze it and modify your survey and design a data sheet that is fitting your needs in your collection. And then you can collect the data which then can be analyzed and the results being represented. It is probably good to have an outline of guiding questions that can help you to define the scope of the project and which condition are the artworks made of synthetic organic polymers in your collection? What is the kind and extent of damages? Is there any danger caused by storage criteria or immediate environments? Are there any particular works that need to be separated from others in stored in isolation like degraded cellulose nitrate, cellulose acetate, PVC, or polyurethane? Are there any further preventive steps necessary, for example, storage in closed containers, involving indicators, and or oxygen absorbers? Are there objects which cannot be exhibited anymore due to the material degradation and contraposition to the artist's intent? How can changes in condition be examined and monitored on a long view? Well, to do this, it helps to develop a data sheet. And I apologize for this sheet that is actually in German because it was developed for the monitoring in the Museum Ludwig. But I'm going to walk you through to each component just to outline what we found important to include within the sheet, which is basically the identification of the artwork and the description of the plastic. We chose to implement more columns because in some artworks of modern contemporary art, you will see different plastics within one artwork. And we wanted to be able to include it in there. Then we have this line to describe the storage, the way it's stored in your storage location and describes the environment. And then there's basically a list of different damage phenomena that are being quantified within this list. And on top of it is a cell for the odour, based on the fact that when you monitor your collection and you open the crate, this is the first thing you recognize, so therefore you wanted to put it at the top of your list. And then once every plastic is monitored and any degradation phenomena is quantified, it will translate into the overall condition of your artwork. The result of the monitoring, which was kind of small because we started with works in the collection of paintings and sculptures and then extended it to the media collection of film and video, were 68 objects. And most of them have been in a fair or good condition, but 20 artworks showed up in the poor condition resulting into conservation actions. And unfortunately, in certain cases, we found unacceptable conditions. So the damages that had been found range from extreme surface dirt, visually interacting with the polymer, as well as extensive grazing, crack, fracture, or active degradation like crumbling and embrittlement. The results that were taken from this monitoring were translated nicely into a deeper analysis of what are the main problems in the collection, what are the main factors of degradation. And when you look at the damage phenomena listed here, and I hope you can read it, the main problems accounted were like surface dirt, staining, solid dirt. Most of it was externally. And most of it was easy to avoid with all these detailed information now being available. So I strongly believe in monitoring. And the advantage of it is once a system is developed, it is actually not that time consuming. Most of the time is spent to develop a form, although there are more and more forms available. And a recent one has been published in the recent pop-up publication. And so you can adapt it to your needs. And it will provide you with a very solid knowledge of your collection condition that can be translated into preventive conservation and treatment. It would also apply to the education of your eye. Over the time, when you look at more and more degradation phenomena, you really learn a lot about it and know what to watch out for. It is a powerful tool of collection management, which also translates into your collection needs that then be translated into your batch planning on a short and mid term and long term view. So I highly recommend, and I saw at the very beginning, that I think 77% of you don't do monitoring on a regular basis. So I would like to encourage you to do so. And I wanted to wrap up here with an image showing the drama by Maurizio Catalan. And you can only imagine what it will take to preserve an artwork made out of plastics exposed to the elements. Thank you. And I guess we are now opening for questions. Yes, thank you so much, Christina and O'Deal. I had a few questions that came to mind. And I hope that others will put in their questions in the chat box. But I did notice that Dee had noticed one of her objects had actually liquefied. And so what she's done is stored it in a freezer storage. Is that something you would recommend if it's observed that there's a severe degradation? I can try. Christina, I don't know what you think that I'll go. Maybe I'm not sure if we agree on all this. But I would say that there's a general rule for keeping plastic, conditions for preserving plastic. Often they favor other artifacts as well. So if you can keep it cool, keep it relatively dry, not humid, and not totally dry. So I don't know, 30% to 50% would be really rough as a guideline. But keep it dark. Don't eliminate UV. That will favor preservation of most materials. When you start going to extremes, I'd start questioning, first, what phenomenon, what mechanism of deterioration are you trying to stop? So freezing, we use it to kill bugs because we know bugs don't like the cold. But with the freezing, with cellulose nitrate, it's generally, I believe, to slow the rate of reaction. So you're trying to slow acid hydrolysis of removal of nitrate groups from your cellulose or acetate groups from your cellulose. With the liquefying, I can see a couple things happening. Either maybe a polyurethane that's liquefying biochemical reaction. Or it could be plasticizer leaching out. And there's some debate that keeping your plastic very cold keeps it more rigid. And that could actually squeeze out more plasticizer. So my answer would be that I don't know. And I think there still is and should be a fair amount of debate. I agree with you, Odile. And generally speaking, well, my advice would be to keep it cooler and keep the humidity to a lower degree. But what is recommended for media collection and those of you who hold film and video in your collection, that it's definitely advisable to keep it in a cold storage. Yes, and we did actually, one of our first webinars is about cold storage of film-based materials. So that's available on Connecting the Collections online community under care photographs. So I can point people to that. I would add that for dealing with photographic materials and motion paper materials and electronic media, a lot of research has been done by industry. So motion picture industry, the people who are making the tape, Eastman Kodak, the Image Permanence Institute, they've done a lot of research. And they know they've got a limited set of variables. They know what materials they're dealing with. They come from manufacturers with a long history of knowledge of the chemistry. So they're more able to make sweeping generalizations about what to do with that kind of material, depending on what your object is. I keep seeing traffic cones coming up on the screen here. Obviously, you wouldn't feel a traffic cone in your typical freezer. But those materials or artist materials are not going to necessarily fall under the same, wouldn't fall under the same recommendations necessarily as film preservation. So just keep it in mind that your object could be very different from the object that's being described in the guidelines. OK. Now, a couple of people have been asking about keeping plastics in isolation. And you mentioned separating artifacts by the type of plastic they may be made out of. Can you talk a little more about how you should isolate plastic artifacts and what types of materials could be used to isolate? Are type of storage containers, I should say, would be used? Well, you certainly want to identify any cellulose nitrate or cellulose acetate in your collection. Because during the process of degradation, it can, at worst, release autocatalytic gases that in turn will affect the surrounding area within your collection. So maybe Odile can talk a little bit more on that, because she is faced with a lot of cellulose acetate, which we didn't encounter at the museum real quick during the monitoring. But we were confronted with also a combination of plastics and other FML-like food and had to make sure that those works are not attacked by bugs. And what has been done is they were sealed in a tile foil, which is a ceramic-coated polyethylene. And then we reduced the oxygen content with H-less in those containers. And in many, many, many cases, just building a nice, dust-free environment for your three-dimensional objects in the storage really helped a lot. I would agree with Christina with the types of plastics that typically one would recommend isolating. They tend to be cellulose nitrate, cellulose acetate, PVC, polyurethane, and rubber. There are two sets of reasons for this. The acetate, the nitrate, and the PVC can evolve acids into the air. And those acids, once they're in the air, they can go travel to some other object that might be sensitive to acid. So there's the concern that, say, cellulose acetate is what I happen to work with a lot right now. If you've got a bunch of vinegar smell in your storage, and you've got some metals there, too, say brass or copper alloys, that metal is going to be susceptible to corroding by that acetic acid. So I would get my vulnerable plastics away from my metal collections. There's some debate of whether or not to store all the cellulose acetate together. I would say that maybe creates a high concentration of acetic acid that could damage your plastic. But I'd certainly say there's, I don't think there's any contention about separating it from metals that could corrode. Another thing I've seen is with polyvinyl chloride, especially, it's heavily plasticized, right? That's a lot of what I'm reading in the questions and comments about things getting sticky. Often you've got that plasticizer migrating out, right? And it's a liquid. So what surface you put in contact with that plasticized material is an issue. So you might want to isolate flexible PVC objects or flexible plastics in general. Keep them off of varnished shells. For anyone who works in a historic house, keep them off of painted shells because that plasticizer can migrate. Just like acids can go through the air and plasticizers can go through the air a little bit. They migrate really well when you put something in contact, especially something porous. And you'll see that, I don't know if any of you have used this. I use it on boats a lot and I've seen collections that use it. It's a mesh that's been flocked with PVC. So it's kind of a non-slip mesh. That's a plasticized PVC. And I've seen that dissolve the surface off of historic furniture. So keep in mind when you're dealing with flexible plastic, you might not want to in contact with varnished or painted surfaces. And so basically, to sum up, it sounds like if you can smell it, it's not a good sign. And you should isolate it from other collections items. And would you put that in some type of an acid-free box, something that has some airflow in it, as opposed to, say, a plastic box or other enclosed metal cabinetry or anything like that? Thank you. Yeah, I'd say put it in a different room. But OK. Not everyone has an isolated room. But there's a debate in this, too, whether to store something in a closed air environment or to exchange the air. If you've got acids coming off of cellulose acetate or acids coming off of PVC, at the same time, you've also got plasticizers leaving. And the plasticizers, you would like to keep them in place. Every time you take them out of the air, a little more is going to want to migrate out into the air. So you run the risk of having a shrinkage problem. At the same time, you don't want high concentrations of acid building in a storage environment, or in a small container, because that can then cause degradation of your polymer. So there's some interesting research being done right now and with acid scavengers, something that in a closed environment, one could expect a scavenger to interact with the acid. So the acid is taken out of the air selectively, and then the plasticizer stays put. But as of now, I don't think that there's a good answer. It seems to be a bit of a let-taste-great-less-filling debate about vented, don't vented, vented, don't vented. But I really don't think we have the answer. OK, so that just brings us all back to monitoring, separating it from the rest of the collection and monitoring it carefully, and maybe getting some specific advice on highly degrading collections from a conservator who could do more research on the specific type of material it is. I would agree on that. OK. Since these needs for the specific artwork might be so special and hard to say it in general, and also it might be designed specifically due to, well, the facility where it's housed to us, I think it over tests to be an individual decision. Right. So and someone has asked about products that were made from the 1980s and beyond when things became even, you know, plastics are even becoming more and more and more complex. Are there any sort of general recommendations on the care of more recent plastic materials as opposed to those made earlier in the 20th century or all these same sort of recommendations apply? This is a deal. I am at the Cooper Hewitt National Design Museum, which is one of the Smithsonian museums this week, because I'm actually in New York. And they've got a lot of stuff in their collections from the 1980s. And what I've noticed is I tend to look at plastics that are more from the 2030s and 40s. So we don't necessarily see more complex formulations happening, but we see different materials being used. So instead of cellulose acetate for injection molded objects, you see a lot of more ABS, acrylic nitrile, butadiene styrene. And it's got its own fillers, often like white pigment. But beyond that, it's not necessarily more complicated. I think the same storage recommendations hold true and that you want to keep it reasonably on the cooler side but not too cold, not humid, not totally dry, so maybe in the 30% to 50% range. And consider having the most important thing probably being out of all of that, probably being reducing the dust. And I should point out the dust. See, these questions are hard because we don't really have necessarily have good answers. But in addition to the environmental conditions you can control through the building, Christine has mentioned a couple of times limiting dust. Imagine if your surface is getting sticky on an object and you've got dust building up on it. How are you going to clean that off? Dust is also very abrasive. It tends to hold moisture on an object. So you want to keep your object as clean as possible so you don't have to clean it, run the risk of abrasion. You don't want to leave dust there that can react and also be unsightly and difficult to remove. And I realize that probably didn't answer your question very well. Sorry. I would like to add that when I think of plastics from the 80s and the 90s that show problems, well, I immediately start thinking about plastics that have been fabricated by the artist or pushed to their limits. And I've seen a lot of mechanical damage due to the fact that the polymer was used in a different way to hold more weight or has been redesigned into a table, into a frame, and was taken away from its original purpose to fit into the artistic needs. And those processes have resulted in mechanical stress and cracks have seen that a lot. That's a good point. And I know I've heard from others that it's very important, especially if you have the ability to talk to a living artist, to learn as much as possible about their fabrication process and what they used and how they used it and to get as much information from an artist when you accession a contemporary art object as possible so that this information would be available to researchers and to conservators later on in their life if it does experience that kind of problem. We had a question about how one should put a session labeling or other labeling on plastic objects. This is probably not a situation where we want to label the object directly like it's possible to do with some other types of material. And so one institution's been trying to encourage using tags. But even would even the twine or a gentle string want to tag be a problem on some of these plastic artifacts? They're certainly linty. It's a problem. It's a challenge to get an accession number onto plastic objects, in part because you don't know what the plastic is. You don't know what the polymer is. You don't know what the formulation is. So I would avoid going for any kind of barrier coat and labeling system. Nothing with the solvent. Nothing that's going to involve an eraser either. But the tags, paper ties with a string, I do see those used. I see those here in the Cooper Hewitt collection, actually. And they're not necessarily tied to the object. So if an object is small and in a tray, sometimes the label is in the tray. And then it falls to having careful collections management to make sure it doesn't get separated. Or maybe tie the tag to a non-plastic component. OK, that's a good suggestion. Yeah, I agree. I would keep the tag close to the artwork, either within its storage box or right next to it in the same location in the container. I would also avoid tying anything directly to the plastic. I can foresee problems with certain plastics. And I think we have seen that a lot already. And then Laura asked a follow-up question. What about Teflon tape for tying labels? I suppose, I mean, the Teflon is not. Actually, I've seen Teflon pick up color from rubber materials now. And it can also be stained by the plasticizer. But it's certainly going to be more in inert-ish material. Maybe if you didn't wrap it like a tape and maybe made it into a floss and used it as a tie. I don't know, Christina, what do you think? It's a good point. I think more research needs to go into it to see if it's applicable for most of the plastics. I don't have an immediate answer. I think more research needs to go into that. Yeah, it sounds like at this point, it's better to be on the safe side. And as Ellen mentioned, using redundant labels, labeling a couple of different ways and that don't touch the objects, having good photographs in a database to make sure it's really understood what objects are. Great photographs. Great documentation. Such a good idea. That was a really good idea. That was a really good point. We just have a few more minutes. And I want to see if we can get it to as many questions as we can, because we've had some good ones. Someone asked specifically about housing for dolls made of cellulose acetate, butrate, and cellulose. Would you, you had given some recommendations earlier, anything different for these that you can think of? Doll diseases, doll diseases, the concern that once a doll, one of these plastic dolls is affected by an acid hydrolysis that it starts spreading across the doll. And I would say you would want to keep, I would store my degrading dolls separately from my non-degrading dolls. And I would rely very heavily on monitoring, keeping an eye on when degradation starts. I'm having a really good sniffer nose to sense. And I would get those pieces away from one another. Christina? Yeah, I totally agree with you. And I mean, you are much more experienced when it comes to cellulose acetate, but I totally agree, it makes sense to separate them. And what about objects that have plastic and metal components, like a piece of jewelry or silverware that has a plastic handle? Keep it cool. Yeah. And you're wondering. People try to wrap the metal component and, well, protect it from interaction with itself. Wadita, what do you think? The conservergram that was recommended, which is a good, you know, it's got good general guidelines. I wouldn't adhere to it too slavishly. But it talks about, I think, wrapping the metal component in film and then leaving the plastic out to air. I would be interested to see what people's experience is with that and how well it works. But beyond that, I'd try to keep the object clean and cooler so that when you drop the temperature for every degree, drop in temperature, you slow a chemical reaction from happening. So when you can slow that speed of, say, acid evolution, you're less likely to have your metals corroding. So I'd go with cold. And if anyone, I would love to hear if someone has tried the wrapping the metal component and to hear what success they've had. OK. I'd love to get just a few more questions. Are you all free for another about five minutes that we can keep going? Sure. OK. We had, I think, a really good question on, well, there's maybe just two parts. But how would you go ahead and handle an object that you've already observing deterioration on? I think maybe when your photos might have shown up cotton gloves, but is that lint problem going to be there? And then what about vinyl gloves? I would use nitrile gloves to begin with. And really want to make sure that the skin is protected very well. If it's an extensive degradation, I might even consider to protect me from breathing it. It depends on the extent. But for sure, I want to make sure that there's no interaction, no contact with my skin. And it depends on the degradation of the polymer. But if you wear a cotton glove and you have some sticky components or liquid components on the surface of your work, you will, for sure, leave some fibers on the surface. So I would rather go for nitrile gloves than any cotton gloves. And then I would use the blue one, right? Yes, the nitrile of the blue or sometimes purple. Yeah. There's market competition now in the color of nitrile gloves. I'm glad I asked. But the unpowdered version would be important because some of those gloves have powder. And then you'd like to get the ones without powder. It depends on what you're trying to pick up, right? Plastics get to be a catchall term for a lot of materials. And they may be in varying characteristics when they're stable and then they degrade in different ways. So there are some objects that are heavily plasticized that over time, their painted surfaces might start disintegrating completely. It might liquefy. You don't want to be handling that at all, right? There's no glove that's going to be good for that. And certainly with sticky objects, limiting the cotton glove is important. But a nitrile glove can take off a sticky, unstable surface as well. I would argue for limiting handling. Like, look with your eyes, not with your hands. You don't need to touch everything. If you watch from people handle objects, it's great to see how many times people want to put their fingers on them. Try not to. And think about how many times you're going to have to turn that object over and interact with it. Try listing it by a tray instead. If you've got it out on a table, put it down on a, if you put something down on the sheet of, say, Tyvek, you can then turn the sheet rather than having to pick up the object. Because you don't want to be marring a surface. You don't want to be a destabilizing loose element. And you don't want to be putting, you don't want to be dirtying that object because they're so difficult to clean. Yeah, so I'm glad you mentioned Tyvek. So you would line any kind of like a box or with Tyvek? I don't know. Any kind of box, but certainly a liner can be helpful. Something that's soft to prevent abrasion. Sticky objects are always the caveat. Sticky objects stick to everything. But Tyvek wouldn't be a terrible choice. So someone had a plastic suitcase, and they were concerned about the interior. Should that suitcase be open or prop it open? It's got metal hinges. Sounds really complicated. I have a plastic suitcase, and I am just reading the question. Does it smell? Well, let's assume it doesn't. Christina, what do you think? I could argue both ways. It would be interesting to know, does it mention what kind of plastic it is? No, right? No. Depending on the age of the suitcase, it could be a number of things. You know, I'd be a little concerned maybe about mold growing on the interior, but that might be an argument for keeping it open. If it smells like vinegar, maybe. But if it's not smelling like anything, I don't know that it matters if you keep it open or shut. Yeah, I agree. And the metal hinges are somewhat corroded. That could be from, it could be an acid effect, but it also could just be a factor of dealing with humidity. Suitcases tend to sit in humid attics and closets and places where they are likely to corrode. Yeah, Christine Schuch has written in. She said, it does smell. She's not sure exactly what type of plastic it turned out in the 1950s. Yeah. Don't know if we could see it going either way. Yeah. You're not going to destroy, you're not going to make a choice either way that it's going to seal the fate of that object. That it's going to be destroyed by either choice. And then someone asked a question about South Asian lacquerware. And if that fits into this sort of category of plastics, someone was able to, D, was able to share a name of a conservator that has experience with that type of material. Do you have any other experience or recommendations for that type? I don't, yeah. Keep it out of the light. Keep it, you don't want, light damage is going to be a problem for lacquer. Heat and extreme conditions can be a problem as well. But light damage is a big problem. So keep it out of direct rays of light and for low light conditions, no light and storage. And keep the temperature well within the museum range. And then what if something is deteriorating to the point that it's off-gassing and I mean, should something just be deaccessioned if it becomes so unstable? So can I pull back the, I can't pull back my presentation. I showed a couple of objects that were completely disintegrated, can you? I'm sorry everyone, I've shared the evaluation link. If you want to click on that link or paste it into your, I put it in the chat as well, if you don't mind, if you have to leave. And asked also how people found us. But I'm going to pull up this, I'm pulling up the slide. So here, if people can see that the object, oh, where's my pointer? OK, you can see the object I'm talking about. It's a plane that's right in the middle of this, towards the middle of the screen. That object was on exhibit with 160 others at the National Air and Space Museum and these started to explode on the wall. They look like they've been shot down. A number of these have been deaccessioned as study materials now, or are being, yeah, a number have been deaccessioned for the worst one so that we can study them because there really is no repairing them. But that's really none of the other, the night of the coupon, the other plane or the pair of goggles have been deaccessioned. They're still accessioned by the museums. So I think that's a discussion one needs to have with one's curator. It's going to depend on the value of the object. None of these are such a danger to the collections that they need to be excised from the building. How we can deal with them by storing them separately. I've seen some severe damages, even in pretty stable materials like PMMA. And an artwork which was meant to be a light kinetic sculpture, so the plexi was supposed to reflect the light while turning around. And the extent of crazing simply conflicted with the way the artwork was intended and therefore had to turn to a study collection too. Yeah, I think Dee mentioned that she had saved something even though it had severely deteriorated as at least a study piece. And sometimes they're useful for studying the technology. They're not necessarily needed for exhibit, depending on the museum that you're in. At Smithsonian we have 137 million accessioned objects. There's certainly a tiny fraction of them is on exhibit. So having the object often is still valuable for visiting researchers, for those of us who are on staff doing research. So there is value to keeping objects even if they're not visually super presentable. Right, well I just wanna ask one more question and then just confirm something. But one last question is, I know with the traffic cones and other construction materials, and what do you do if there is dirt? Either that items become tacky over time as attracted dirt or dust or it came into the collection with dirt on it. What do you suggest one do with that? I would suggest that for a museum collection, it gets, the answer is it's complicated. So what I would consider is bringing in a conservator to do a survey of that object or a survey of the collection and then to prioritize objects that should be considered for treatment down the road and then prioritize resources to, allocate resources to the priority treatment. So I'd say I'd have a conservator do it. Yeah, no cleaning yourself. The soon as you, well, the soon as you put it, you know, you can go wash a, I can wash a traffic cone, but the second it becomes an artifact, then the longevity, the whole lifespan, expected lifespan of the object has changed and your interventions matter much more. So I would contact a professional conservator for that. Definitely. And then I just wanted to confirm again, Dee had said she has a faux tortoise shell hair comb that had actually liquefied and she has been keeping it in a freezer storage. But you had, I just wanted to reiterate, make sure I had it right, that for most it depends, but in general keeping things cool, 30 to 50% relative humidity, dust-free environment, is usually, if it's a non-fill material, usually the best way to go for a plastic artifact. Is that correct? Yeah. Yeah. You're safe with that. I mean, you might wanna go into even more radical decisions with certain plastics, but generally speaking, this would be my advice, yeah. And a hair comb, if it's a cellulose nitrate hair comb that's turning liquefying or getting, there's a difference between it getting sticky and it liquefying, but if it's really on its way out, you're not going to stop that from happening. You might slow it a bit. So one consideration would be, what is the future outlook for this object? Is it ever going to be exhibitable? Does it have research value? If it's in a freezer, is it going to be usable? Right. I think once things go into cold storage, it's expensive to put things in cold storage, and you do limit access to that object at that point. And I think with a lot of the cellulose nitrate material, once it's that far gone, if it's liquefied, then its demise seems maybe inevitable. Right. And so then just, again, would cool be 40 to 50 degrees Fahrenheit? I don't know. Oh, I have to tell you, I'll tell you to my head. I know if you want to, but we don't know where you want to. I would just say a range, just like the 30 to 50 percent of age. 40 to 16 cells is usually recommended, which is probably, yeah, about that range, yeah. Yeah, that's what is currently at 5. I think we need more research in that area, so I'm not. And I get nervous putting out this. Smithsonian said that we should start at the Smithsonian. This Smithsonian employee is saying that we don't know. So yeah, I hesitate to give numbers. OK, so I think we're wrapping up today with caution and observation, observation, observation. Yeah, well, thank you so much, Christine, and no deal for the time today. We do need to wrap up and the recording. We will be posting this on the Connecting to Collections online community with your permission. We'd also love to post the PowerPoint, and so people could have a better or a closer look at some of the forums you showed. And obviously, we have our discussion board on the online community. So if there are other specific questions, maybe we could filter those to you as well. Of course. Thank you so much. That sounds great. Thank you so much for having us. This was a lot of fun. And thanks for all the good comments that we see running up the screen right now. This has been great. Thank you so much. Thank you for your time today. Thanks everyone for joining us. Thanks.