chemical facts

/ chemical facts/ textiles: the ugly

© Design reproduced with permission by Extended Diploma in Art and Design student at Colchester Institute 2011

Current technological advancements in the textile industry include the development of textiles that are smarter, stronger and cutting-edge. “Cosmeto-textile” products (Hibbert, 2004), created through sub-micron nano-engineering and genetic manipulation can automatically respond to temperature fluctuations, monitor our mood, administer medication, mimic functions and properties from the natural world and apparently assist with our well-being, but this leads me to question, how “healthy” are these textiles, and what of traditional textiles, such as cotton? Is there such a thing as a healthy fabric which does not have an impact on either the environment or humankind?

Chemical finishes are often applied to a garment to give it various properties, such as shrink resistance, crease resistance, odour resistance, water-repellent, anti-bacterial, anti-fungal, anti-static, permanent-press, softening agents, easy care treatments or flame and soil retardants, adding a further mixture of potentially harmful chemicals to the cocktail. Most of the chemicals used for these finishes have proven to have negative effects on human health. Dyes and garment finishes are known to result in an array of health problems such as skin rashes, headache, trouble concentrating, nausea, diarrhea, fatigue, muscle and joint pain, dizziness, difficulty breathing, irregular heart beat and even seizures. Symptoms in children can include red cheeks and ears, dark circles under the eyes, hyperactivity and behaviour or learning problems, (Aura Herbal Wear, 2007-8).

Many of the hazardous chemicals once used by the textile and clothing industry have been banned, in particular chemicals found as residues in clothes that have been proven to cause cancer, such as benzidine, linked to “exceptionally elevated risks” of bladder cancer (Organisation for Economic Co-operation and Development, 2002), but other hazardous chemicals used commonly in the textile industry such as lead, nickel, chromium IV, aryl amines and phthalates still continue to be widely used, (Greenpeace, 2010). The following list is not exhaustive, but highlights some of the worst offenders:

Wrinkle-Resistant Finishes
Anti-wrinkle finishes, which are used on a broad range of clothing uses a resin that releases formaldehyde, the chemical that is usually associated with embalming fluids. Wrinkle-resistant finishes are used to keep the fabric’s fibres in place after a spin in the washing machine and also often serve as a preservative and to prevent mildew while clothes and other items transit from factory to store.

Formaldehyde is a colourless gas with a pungent, suffocating odour. It is an irritant on inhalation, direct contact with skin or eyes and on ingestion. Formaldehyde can cause a skin condition called contact dermatitis, an allergic reaction that causes itching, redness and blisters, but more importantly, it is also classified as a carcinogenic hazard. Despite this, the United States does not regulate formaldehyde levels in clothing and government agencies do not require manufacturers to disclose the use of the chemical on labels. The International Agency for Research on Cancer (IARC), a non-regulatory body, has classified formaldehyde as probably carcinogenic to humans, and in EU countries formaldehyde is classified according to the Dangerous Substances Directive as a category 3 (C3), which is the weakest class of carcinogenic hazard, (Formaldehyde Working Group, 1999).

Flame Retardants
Brominated flame retardants (BFRs) are also often added to textiles and clothing, so that in the event of a fire, they burn more slowly. BFRs have been found to be persistent, bioaccumulative and toxic (PBT) and have endocrine-disrupting properties, particularly causing thyroid imbalances. Negative health impacts have been shown on the liver, the brain and the nervous system when tested on animals, (Ashton and Salter Green, 2006: 35). Often these chemicals are impregnated into products we have close, long lasting contact with.

Nano finishing techniques can also provide flame retardancy, UV blocking, wrinkle resistance, anti-static and self cleaning properties, however a report in Ecotextile News (October 2010) raises concerns about the environmental impact that nano silver particles in particular may have if they enter wastewater, as they accumulate in biosolids (sewage sludge), and as this is often disposed of through land application in the form of fertiliser, it could potentially affect soil-dwelling micro organisms. The affects of this new technology is largely unknown and currently in the US, clothing labels are not required to disclose the presence of nano- materials in end products.

Water-Proof Finishes
Perfluorinates (PFOs) are the group of chemicals used to water-proof clothing. They are found in outdoor clothing, such as ski wear and “breathable” fabrics, as well as crease resistant clothing. These chemicals are very persistent, sometimes being referred to as “eternal” compounds, because they do not degrade. Exposure to PFOs such as Perfluooctane sulfonate (PFOS) and Perfluooctanoic acid (PFOA) may cause birth defects, adversely affect the immune system and disrupt thyroid function. The US Environmental Protection Agency considers both PFOS and PFOA to be carcinogenic and occupational exposure has been linked with increased occurrence of bladder cancer, (Ashton and Salter Green, 2006: 39).

Dry Cleaning Solvents
Approximately 90% of all EU dry cleaners use the solvent perchloroethylene (PERC) in their dry-cleaning process. PERC has been known to cause serious environmental and health impacts, as it is toxic to the liver and the central nervous system, can accumulate in the body and is probably carcinogenic to humans. Studies have shown that the compound induces leukaemia in rats and increases risk for oesophageal cancer, non-Hodgkin’s lymphoma and cervical cancer. It has been shown to cause liver tumours in mice and kidney tumours in male rats, (Greenpeace, 2005). PERC is very persistent in ground water and soil, as well as toxic to the aquatic environment and strangely, everything perchloroethylene comes into contact with at the dry cleaners must be handled as ‘hazardous waste’ except the dry cleaned clothes we wear! As a result, dry cleaning operations using PERC are regulated under the EU VOC Directive, which requires that VOCs (Volatile Organic Compounds) that are carcinogenic, mutagenic or toxic to reproduction should be replaced, and many EU countries have now set national regulations.

Sandblasting is another fabric finish, it is used to create a faded or worn out or bleached look on denim. The technique uses an abrasive material, usually sand, which is blasted against the fabric under high pressure. The process often uses natural sand which contains silica and can cause silicosis, as the crystalline silica dust particles can be easily inhaled, penetrating the pulmonary alveoli and the connective tissue, which gradually impairs lung capacity and the ability to oxygenate the blood. Symptoms include shortness of breath, and as the disease develops, it becomes increasingly difficult to breathe; this puts strain on the heart and eventually leads to death.

A report undertaken by the NGO Fair Trade Center, and co-funded by the Clean Clothes Campaign, indicates that cases of silicosis are on the increase, with 50 deaths registered in Turkey and an estimated 5000 workers who have developed silicosis prior to the banning of the practice by the Turkish government in March 2009. Since the ban, the sandblasting industry has moved to other countries, such as China, India, Bangladesh, Pakistan and parts of Northern Africa. Sandblasters within the industry are most likely to suffer from silicosis, however residues of silica can also be found on the finished products.

Bleaching makes fabric white and usually involves the use of chlorine. The primary environmental concern with chlorine-treated textiles is the industrial wastewater from chlorination facilities. Some chemicals like dioxins and furans are created unintentionally by industrial processes using chlorine. Dioxins and furans are PBTs, they are a group of chemically-related compounds that are persistent environmental pollutants; they are highly toxic and can cause reproductive and developmental problems, damage the immune system, interfere with hormones and also cause cancer.

Scientists estimate that there are many other unintentionally created by-products which are generated by industrial processes which have not yet been  "discovered", since no tests have yet been developed that would fully identify or describe these by-products.

Textile Dyes
Dyeing gives a textile its colour; dyes consist of soluble coloured compounds suspended in a medium. To dye a fibre is to affix the molecules of the dyes as solidly to the surface as possible through a chemical reaction (chemical absorption), which varies depending on the pairing of dye and fibre.

Both natural and man-made dyes can be used for dyeing textiles, along with other processing chemicals that must be washed out after dyeing, however the dyeing process uses a lot of water, energy and chemicals. On average, a t-shirt that weighs 200 grams needs 16-20 litres of water to dye it and every year the global textile industry discharges as much as 40,000-50,000 tonnes of dye into rivers and streams.

Twentieth century fibres such as nylon and polyester were difficult to dye with natural dyes and so gradually the use of natural dyes for textiles became a niche market, being replaced with synthetic dyes. Synthetic dyes are based on a particular type of chemical composition. Some of these dyes are acid (anionic) dyes, basic (cationic) dyes, neutral premetalized dyes, sulfur dyes, vat dyes, reactive dyes, or pigment dyes. There are also many different methods of dyeing for different types of fibre and at different stages of the textile production process. These methods include direct dyeing and yarn dyeing (the most widely used methods); stock dyeing; top dyeing; piece dyeing; solution pigmenting or dope dyeing or garment dyeing.

Some azo-based dyes, according to the Federal Institute for Risk Assessment, can under certain conditions, break and produce two new chemical substances called aromatic amines, which contain metallic elements, and as a garment is worn these chemicals, which are proven to be carcinogenic can be absorbed through the skin. Aromatic azo compounds are usually stable and have vivid colours such as red, orange, and yellow. Until very recently, these chemicals were widely used.

In the case of aromatic azo dyes, the European Union passed a law in 2002, which bans all azo dyes which “may release one or more carcinogenic aromatic amines in detectable concentrations” and also bans imports of textile and leather products with excess contents of azo dyes. This law has been ratified by EU member states and according to PAN UK, any textile product sold in Europe, in theory should not contain any azo dyes by law. However, as most textile products are processed outside of Europe, and because of the complexity and lack of transparency of the textile supply chains, it is not clear how well this law will be implemented.

Textile Printing
Traditional textile printing involves the application of a colour paste, made up of dye pigment, a thickening agent and other chemicals onto a fabric in a specific or selected area. In comparison to dyeing this reduces resource consumption, but can impact on watercourses through the cleaning process of screens and squeegees, which often requires the use of solvents with associated volatile organic compounds (VOC’s) which create emissions to air as the print pastes dry. Some commonly used textile printing inks harbour carcinogens.

Many screen printing companies use PVC Plastisol inks for printing. Such prints may be relatively cheap to apply in complex designs but other printing techniques which do not rely on the use of phthalates, alkylphenol ethoxylates and other hazardous chemicals are now widely available.

Digital printing which uses ink jets involves the propelling of tiny droplets of pigment onto the fabric and does not require the use of solvents for cleaning. Pigment-based inks can also be cured with ultra-violet curing technology, where UV radiation is used to rapidly fix the printing ink without the emission of odour or toxic by-products.

Transfer printing uses the technique of sublimation to transfer dye from a paper which is first printed with volatile disperse dyes and is then heated, together with the fabric in a heat press. In transfer printing only the dyes are deposited on to the fabric, so no washing is required and no effluent is generated, however this technique is currently only suitable for some synthetic fibres.



/ textiles: the good

/ textiles: the bad

/ textiles: the ugly

/ sustainable textiles

/ REACH legislation

/ textile labelling

/ glossary

/ bibliography and links