When did people first recognize that plastic degradation was a problem?

For a long time, no one noticed that plastics were degrading, because they were used for throwaway objects. But by the 1960s, a cellulose acetate sculpture by Russian constructivist artist Naum Gabo, at the Philadelphia Museum of Art in Pennsylvania, was disintegrating. Its value made people take notice. When I joined the V&A in 1994, some people still saw plastic as an imitative material rather than a material in its own right. Now, they respect it as a medium that can take any shape, that is used to create objects and artworks that you couldn't make any other way.

What is in the V&A's plastic collection?

We have shoes, accessories and bags from the 1920s, when manufacturers used cellulose acetate or nitrate to imitate natural materials such as amber, ivory and tortoiseshell, for example in intricate hair combs. In the 1930s and 1940s, couture designers including Elsa Schiaparelli played with the new materials, which by then also included semi-synthetics such as casein (made from milk protein and formaldehyde), in decorations, buttons and fabrics. From the 1960s, pop-art furniture made of polyurethane (PU) and other plastics emerged, including a sleek single-mould chair by Danish designer Verner Panton and inflatable furniture. There were also polyvinyl chloride (PVC) raincoats and boots. The V&A has beautiful radios and cigarette cases made of Bakelite, but that is pretty stable. In our outpost at the Museum of Childhood in London, we have a huge range of plastic toys, including PVC dolls and PU foam figures.

How do plastics degrade?

Only five types degrade catastrophically in reaction to humidity, light and air — it's a problem of thermodynamics. It can take from a few years to a few decades. Cellulose acetate and nitrate react with moisture in the air and crumble, producing acid vapours that can corrode anything that shares their display cases. For PU, the problem is oxidation: once additives such as phenolic antioxidants are used up, the plastic crumbles. (The Museum of Childhood's PU foam puppets of television character Larry the Lamb have succumbed completely.) PVC degrades because of the plasticizer molecules that make it flexible. These sit in the mixture and creep up to the surface, making it sticky. Both plasticizers and the base polymer can undergo a reaction that makes the surface dark. Finally, natural rubber, which filled the cushions of pre-1950s upholstery and formed shoe soles, will oxidize and become brittle over time. For all of these, we can stave off the process through specialized storage and display conditions, but we can't prevent it entirely.

Plastic butterfly sunglasses from the 1960s. Credit: www.lunetiervintage.com

What happens when the museum acquires a new plastic object?

We have to weigh up the care and cost demanded by the plastic's type, age and condition. Many older objects are not labelled, so you need to discover what plastics they are made of. We use an infrared microscope to find the material's fingerprint — how it absorbs different wavelengths of light. Smell and appearance are important, but not conclusive. Our intern Carien van Aubel is looking for features in dozens of test objects to spot similarities — perhaps production techniques or usage — that would help museums without our testing facilities to identify polymers in new acquisitions. This also applies when we put together touring exhibitions: we need to know whether the items we borrow can withstand the rigours of transport and display. In 2013, for example, we checked costumes for the V&A's exhibition David Bowie Is, including PVC boots and a skirt-like structure stiffened with polyurethane foam.

Are there any V&A pieces that are ticking time bombs?

I wouldn't say we have anything that dramatic. Much of our 3D-printed furniture is white nylon, which can yellow. We have a little cellulose acetate box by early-twentieth-century French glassware designer René Lalique that is definitely warping. The problem is worse for modern-art museums, because they have many contemporary artworks that incorporate plastics. From the 1980s, the number of plastics available exploded, and people largely stopped using the least stable ones. But plastics do not last forever, because — unlike wood, metal or stone — they can be damaged by adhesives used for repair. So even something made of Perspex might last only a century, although we don't really know because the material hasn't been around for that long.

What brought you to the V&A?

I have always been interested in collecting old objects, but mainly plastic items that you would pick up in junk shops, such as Bakelite cigarette boxes. My first degree is in chemistry and my PhD in materials science, focusing on polymers; so when this job came up, it was nice to marry the science with art and design.

Do artists and manufacturers factor plastics degradation into their work?

No. A lot of modern art is made of plastic, and often artists, aiming for a particular effect, ignore the manufacturer's instructions on how to mix it. So the plastic might degrade even more quickly. We also now have bioplastics, which are made to degrade. With these, you'll definitely be fighting against the tide. Footnote 1