In 2019, Ikea announced that it has developed curtains that it claims can “break down the usual indoor air pollutants.” The secret, according to him, is the special coating of the fabric. “What if we can use textiles to clean the air?” Asked Ikea product developer Mauricio Afonso in a promotional video for Gunrid curtains.
After explaining that the coating is a photocatalyst (“similar to photosynthesis found in nature”), Afonso is shown looking up in the transparent curtains while playing sublime music. “It’s amazing to work on something that can give people the opportunity to live a healthier life at home.”
Puzzled by these claims – how could a mineral coating clean the air? – Avicenn, a French non-profit environmental organization, is investigating. Independent laboratory tests of Gunrid textiles report that the samples contain small particles of titanium dioxide (TiO2) – a substance that is not normally toxic but can be carcinogenic by inhalation and potentially in other forms – presumably giving “self-cleaning” properties to things. such as paint and windows when exposed to sunlight.
Image of a Gunrid curtain fiber under a microscope in laboratory tests showing nanoparticles on the surface. Photo: LNE
These small particles or nanoparticles are at the forefront of materials science. Nanoparticles come in all shapes – spheres, cubes, fibers or sheets – but the crucial thing is their size: they are smaller than 100 nanometers (human hair is approximately 80,000 nm thick).
There are many nanoparticles in nature. Nanohairs make the gecko’s legs sticky, and nanoproteins make spider silk healthy. But they can be manufactured and because they are so small, they have special properties that make them attractive in a number of endeavors – not just for companies like Ikea. In medicine, they can transport cancer drugs directly to tumor cells, and nanosilver is used to cover medical airways and bandages. Nanos can target pesticides to parts of the plant or release nutrients from fertilizers in a more controlled way.
They also have more mundane applications. Synthetic nano is added to cosmetics and food. Nanosilver is used in textiles, where it is said to impart antibacterial properties to gypsum, fitness wedges, yoga mats and pants for the period.
But scientists like Avicenn are concerned that when these household items are washed, recycled or discarded, synthetic nano releases are released into the environment – making their way into the soil and sea in ways not yet understood. Some scientists believe that nanoparticles may pose an even greater threat than microplastics.
Synthetic plastic nanoparticles have been found in the ocean and in the ice at both poles. Nanoparticles from socks and sunscreens have been found to contaminate water, and some nanoparticles have been shown to adversely affect marine wildlife, including fish and crustaceans. As with antibiotics, resistance to antimicrobial nanosilver may develop – silver-resistant soil bacteria have already been identified.
Ikea Gunrid air purification curtains. They were withdrawn from sale, which the company said was because “the functionality was not as effective as expected.” Photo: Ikea
Little is known even about where the nanoparticles are, let alone their impact on the environment. Because they are so small, most experiments are conducted in laboratories and it can be difficult to determine where they are applied.
“The main problem with these substances is that we can’t measure them – we know they’re there, but they’re so small they’re hard to detect, so you don’t hear so much about them,” said Nick Vulvoulis, a professor of environmental technology. at Imperial College London.
He is concerned about the uncontrolled use of nano in consumer products. “If nano is used properly in applications that are useful or useful, that’s justified, but if it’s used everywhere and everywhere because it has certain properties, it’s crazy.”
Synthetic nanoparticles are not inherently harmful. Like their natural cousins, many are metal-based, but can be made from any substance. It is crucial that, unlike chemical compounds, they cannot be dissolved. Their small size gives them, paradoxically, a huge surface, which makes them behave differently from “non-nano” versions of the same material. This can make them more mobile, more reactive – and potentially more toxic, depending on the shape, size, type, way the substance is released into the environment and its concentration.
And released into the environment they are on a huge scale. According to Avicenna, the release of sediment is most likely during production or disposal, but it can also occur when washing objects – which is known to happen with nanosilver-containing fabrics. Sewage systems can’t catch them and they end up in the ocean: the OECD says even modern wastewater treatment plants can’t handle nanoparticles.
We need to make sure that nano is only allowed for specific and basic uses in order to minimize any adverse effects Matilde Dechevery
From a health point of view, inhalation is the most harmful route of exposure to nano, such as TiO2, for workers and consumers. Avicenn’s tests concluded that the average particle size was 4.9 nm and all 300 analyzed particles were below the official nano threshold of 100 nm.
Ikea insisted that its own tests showed that TiO2 particles were “properly bound to the tissue” and “did not pose a risk” to customers, and said it took workers’ safety very seriously. The company did not call them nanoparticles and said that once integrated into textile surfaces, there was no “good standard method for measuring the particle size distribution of a material”, acknowledging that EU definitions of nanomaterials were under review.
“We recognize that tests and measurements of nanoparticles are complex, especially for materials containing particles that tend to form agglomerates,” it said.
As for Ikea’s curtains, which emit TiO2 nanoparticles when washed or disposed of, Ikea said it was “confident that the treatment is properly related to the fabric and therefore sees no risk of inhalation of the treatment”, but acknowledged that “as in any textile, textile parts may be separated during use or washing ”.
Many nano do not stay long in the environment. However, as they are constantly discarded, the levels remain relatively constant. “Nanos are ‘pseudo-resistant’ because they degrade quite quickly, but continue to enter the environment,” says Vulvulis.
His main concern is whether nanoes become carriers of other compounds under scientific debate. In 2009, Spanish scientists suggested that nano-nanoes could bind to and transport toxic pollutants and possibly be toxic themselves, generating reactive free radicals. If other toxic pollutants “cling” to nano surfaces, they claim that marine plants and animals can absorb them more easily.
Other scientists suggest the opposite: the organic matter in wastewater covers nanoparticles, making them less active. Others fear that nano nano may cause the effects of “toxic cocktails” – making them more harmful in combination than the individual substances alone.
Fibers under high magnification. “Nanoparticles are often advertised as silver bullets against pollution or bacteria,” says one scientist, “but we need to make sure that the treatment is not worse than the disease.” Photo: Perov Stanislav / Alami
So far, synthetic nanomaterials are relatively scattered in the sea and are unlikely to significantly affect marine animals, said Dr. Tobias Lamel of the University of Gothenburg, who studied copper nano. But he warns: “It is possible that the concentration of some manufactured nanomaterials in the marine environment may increase… It is important to monitor this.”
Given the huge question marks, Avicenn wants tighter nano regulations and more caution in product design. “Companies are eager to sell innovative and sophisticated products, but need to thoroughly assess the balance between the benefits and risks of each step of the product life cycle,” said Matilde Detchevery, Avicenn’s policy manager.
From August, the EU will ban the use of TiO2 nano in food (where it is called E171), and the European Commission recently announced that 12 nanomaterials will soon be banned in cosmetics.
Detcheverry says: “As scientific knowledge on the environmental and health impacts of engineered nano, such as silver and titanium dioxide, advances, we need to make sure that nano is only allowed for specific and basic uses to minimize any adverse effects at source and [ensure they are] it shall not be released uncontrollably. ”
Two years after the launch of Ikea’s Gunrid curtains, Avicenn tried to buy more for additional tests, but they were withdrawn from sale.
Ikea told the Guardian that Gunrid remained “safe to use as a traditional curtain”, but was withdrawn because “the functionality was not as effective as expected”. If this is true – for example, that although TiO2 has proven photocatalytic properties and is used in self-cleaning and air purifying products, its effectiveness on curtains can be localized and not powerful – then at least Ikea’s experience suggests that the benefits of nanoparticles may not outweigh the potential and often unknown risks, Detcheverry says.
“Nanoparticles are often advertised as silver bullets against pollution or bacteria,” she said, “but we need to make sure the treatment is no worse than the disease.”
Gunrid was just one product out of many thousands that use nanoparticles. As Afonso of Ikea says in the video: “What’s so great about Gunrid is that this technology can be applied to any textile.”
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