Sustainable textile art? – An investigation into flame-retardants by Lisa Nilsen

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Image of threads ©The National Heritage Board

Flame-retardants are part of our lives, whether we like it or not. In order to achieve a high level of fire protection, flame-proofed textiles in public places are more the norm than the exception. We know that if a flame-retardant is applied to a textile after its production, its lifetime expectancy is greatly reduced. So what about textile art made especially for theatres, conference halls and other public spaces? Recently, the Swedish National Heritage Board had an excellent opportunity to find the answer to this question – in the United Nations headquarters in New York.

The case of the UN Headquarters textiles destroyed

The iconic United Nations (UN) building complex in New York was designed by an international team of architects and completed in 1952. The Economic and Social Council Chamber (ECOSOC) was created by Swedish architect Sven Markelius and the interior design of the room presented to the UN as a gift from the Swedish State.
A grand stage curtain, designed by Marianne Richter, was commissioned and woven in Sweden. However, only fragments of the curtain remain today, while its successor, a print from the 1950’s by Markelius (though not specifically designed for the ECOSOC) installed in 1989, also deteriorated beyond repair. In 2010, restoration of the
ECOSOC began and Sweden responded to the request to support the conservation of the artworks. This time the National Heritage Board got involved. A research project, ‘Sustainable textile art?’ was created and coordinated by senior conservator Margareta Bergstrand.
She said “We regard the ECOSOC as part of our modern heritage”, and explaining why the two curtains did not last, she added that New York fire regulations required the stage curtain to be treated with a flame-retardant, which was applied in New York. As early as the beginning of the sixties, the Swedish authorities were informed that the curtain did not look its best. It was shipped to Sweden in 1967 for washing and other treatments.
The Richter curtain was returned but soon appeared to be in a sorry state, according to pictures taken at the time. In 1989 it was replaced by the Markelius print which had been treated with flame-retardants in Sweden before being installed and met the same fate as the Richter curtain – a premature death.

Research project on flame-retardants

With samples from the two stage curtains, and two other spectacularly deteriorating works of art taken from Swedish public offices, Margareta Bergstrand and her colleagues at the Unit for Conservation Science at the National Heritage Board had four case studies to investigate. A thorough literature search showed that the problem had been identified in 1969 by Karen Finch in an article in Studies in Conservation (, but very little research on the subject had been performed since then (see further reading).

The study is now complete. The research team can confirm that the flame-retardants indeed contributed to the degradation of the two UN curtains as well as to the two other case studies. They concluded that flame-retardants containing inorganic water-soluble salts and/or organic phosphor or nitrogen compounds affect textile materials immediately upon application. They weaken the material according to the fluidity test and mechanical tensile test. They also acidify the material, with a drop in pH, and make the material more sensitive to light, UV radiation and humidity. Furthermore, they influence the weight of the material at higher humidity when salt attracts moisture; added weight means mechanical stress.

As well as this important information, it was also found that wet cleaning of textiles treated with flame retardants raises the pH, but does not ameliorate the condition of the material: the inherent properties are weakened.
“We know today that washing was the nail in the coffin for the Richter curtain,” says Margareta Bergstrand. “Our research has showed that washing flame retardant treated textiles in order to neutralise the pH to strengthen it, can indeed have the opposite effect.”

A generation of female textile art to vanish?

Reading about these case studies, as well as other examples from an inventory during the project, it is striking that all but two textiles were made by women artists. Does this mean that a generation of female textile art could vanish totally?
“That is an interesting point of view,” says project leader Margareta Bergstrand. “Because textile was a typical female medium at that time, this is of course a risk.” Both Marianne Richter and her contemporary fellow artist Randi Fischer have had at least one of their most important works destroyed because of flame-proofing. They belong to an
important generation (the latter being part of the Swedish famous “The Men of 1947” (sic!)), who, according to Margareta Bergstrand, are today being recognised as the great artists they are.
In one of the case studies, the artist was commissioned to make curtains for a public building, and asked by the client to treat them with flame-retardants. When the curtains dramatically degraded after five/six years, the complaints upset her terribly as she knew she was not guilty of bad craftsmanship. She contacted the National Heritage Board and they obtained unique research material by comparing the original non-treated yarn with the treated.

How useful is flame-proofing textile art?

Margareta Bergstrand has encountered this issue both as a textile artist and later as a textile conservator. She managed to save the stage curtain she had designed for a lecture hall from being treated with flame-retardants by talking to the local fire prevention authority. “The fire engineer listened to the argument that wool in itself contains fire-retarding properties, and very professionally saw the whole picture, including how the university in question organised their fire evacuation.” And surely that is the point – organisational measures are often more efficient with regular training, thorough risk analysis and a “security culture” firmly rooted with staff and volunteers. “Applying flame retardants can give you a false sense of security”, says Margareta Bergstrand.
Someone who successfully fought against flame-retardants on art is Alison Lister, Director at Textile Conservation Limited, a conservation practice based in Bristol, UK. When conserving a series of 1950’s wall hangings (attributed to Hilary Bourne) in the Royal Festival Hall, London, seven years ago, her company was asked to provide a big sample of the work itself for fire testing, and to provide a quote for a fire-retardant treatment. When quizzed about the arguments she used to dissuade the client from using a fire-retardant on the textiles, she refers to a letter she wrote, where she politely, but also quite humorously, asked questions, including for example what would they do with a 17th Century tapestry.
Reading between the lines, it is possible to see her analyses of the risks and suggestions for alternative options - the very job a fire consultant should do before choosing the easiest option, i.e. treatment with a flame-retardant.
Another interesting example comes from well-known Swedish textile artist Helena Hernmarck. When creating a woven wool tapestry for a commission in the U.S., the work had to be tested for flammability. The researchers subjected a test sample to a cigarette, a flame from a candle, a direct flame and even a torch at a 45-degree angle for approximately 60 seconds (the tip did not make contact with the sample). Though the sample charred, it showed no sign of igniting.
Today, there is a great deal of experience in organisational fire prevention. Flame-retardants on textile art should no longer be an issue. Furthermore, textile artists may fear that their art will not be commissioned because of the destructive potential in flame-retardants, and customers may prefer tiles or steel to textiles. “We need to talk about this,” says Margareta Bergstrand. “There are lots of examples of untreated textiles from the same time period as our case studies. They show few, if any, signs of degradation and have already surpassed the limit of sixty years given by the National Public Art Council for the new ECOSOC curtain.”

And the new curtain for the ECOSOC? Yes, a brand new stage curtain, designed by artist Ann Edholm, has been made by the HV Ateljé in Stockholm. A test width of wool lined with Trevira CS® has passed rigorous U.S. fire testing. “No flame-proofing will be required!” exclaims Margareta Bergstrand. “It is very satisfying to see that these examinations and tests may result in specific advice for both the production of new works of art and for conservation.”

Further reading

Bergstrand, Margareta et al., Fire! A Twofold Risk for Textile Art. An Investigation into the Consequences of Flame Retardant Treatments. ICOM-CC pre-print of the 16th Triennial Conference in Lisbon 2011.
Finch, Karen: Note on the damaging effect of flame-proofing on a tapestry hanging. Studies in Conservation, 14 (1969), p 132.
Hallgren, Cajsa, proofed textiles in museums and conservation. Incredible Industry. Preserving the evidence of industrial society. Conference Proceedings of the Nordic Association of Conservators 18´Conference, Copenhagen 2009.
Halvorson, Bonnie G., Flame Retardant Finishes for Textiles, Textile Conservation Newsletter, no 29, 1995, pp 20-26.
Lister, Alison, Banks, Jo, Unlimited access: safeguarding historic textiles on open display in public buildings in the UK. Conservation and Access: Contributions to the 2008 IIC Congress, London 2008.
Lister, Alison, Banks, Jo, Hand, Vicky, The Conservation of the Original 1950s Textile Hangings in the Auditorium of the Royal Festival Hall, London. Facing Impermanence: Exploring Preventive Conservation for Textiles: Preprints North American Textile Conservation Conference 2007, Washington DC, November 6-9 2007, pp 93-105.
Lennard, Frances, Behaving badly? The conservation of modern textile art. Restauro 5/2006, pp 328-334.
Rockliff, Doreen and Kerr, Nancy, Fiber retardant finishes for fiber art: a conservation perspective. Preliminary findings, Preprints of the 7th Triennial Meeting of the Conservation Committee of ICOM, Copenhagen 1984.

Many thanks to Helena Hernmarck and Alison Lister.
Lisa Nilsen is a free-lance conservator, specialising in preventive conservation and housekeeping, including disaster preparedness. Based in Sweden, she came across this fascinating subject as editor for the Swedish IIC newsletter and decided to spread the word