A solvent is usually a liquid that is used to dissolve substances or materials, such as pigments, in a solution, the dye. Solvents are used in several stages throughout the production process. Water can often be used as a solvent, but it cannot be used for everything. Different types of organic solvents are often required. Many of them are hazardous when inhaled or when they come in contact with the skin. Solvents are often used in large quantities both in the production process as well as for cleaning of the machinery. Many solvents are also flammable and some are explosive. Careful selection of solvents can be an efficient way to reduce hazards, especially in the work place.
Among the solvents that are hazardous to human health are trichloroethylene, benzene and methanol.
Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, dispersants, softeners and antistatic agents and are used in many stages of the textile process. Commonly used surfactants are alkyl phenol ethoxylates, which are problematic since they are endocrine disruptors, meaning they could interfere with the hormone systems of mammals. Commonly used softeners which are intentionally applied to the fabric are DHTDMAC, DSDMAC and DTDMAC.
Water and soil repellents
Water repellence is often a desired property, especially for fabrics that are used outdoors. A popular way to achieve this is to impregnate the fabric with fluorinated or perfluorinated compounds. Some of these substances, including PFOA and PFOS (sometimes called C8 technology), have been known for many years to have hazardous properties. This has led to the increased use of other perfluorinated substances. However, many of these (including those sometimes known as C6 or C4) have been shown to have problematic properties as well. And even if the perfluorinated substances many times give the fabric desired properties, it is important to reflect if these properties are really necessary for the specific purpose. Especially if the focus is water repellence. There are available alternatives that are not based on fluorochemicals and that can be used to create a water-repellent surface. One option is to use dense cotton fabric which swell in contact with water or a dense synthetic fabric woven from microfibers yarns, both impregnated with wax based alternatives to achieve a repellent effect. In addition, it is also possible to achieve a repellent property in synthetic fabric with a variety of methods without using fluorinated/perflourinated compounds.
It is of course equally important that also “refill” repellents sprays sold to consumers are free from these compounds and that the manufacturer and retailer actively promote alternative products, free from fluorocarbons.
Biocides and pesticides
Biocides and pesticides are used to prevent living organisms from thriving on your goods. Biocides can be used to prevent anything from bacterial growth to grazing by large animals, and are designed to be hazardous for the target organisms. It is a great challenge to develop biocides that will not harm other organisms, including humans.
Pesticides are a type of biocide used to defend crops from damage by insects, mould or weeds. Residues of pesticides may therefore be present in fibres such as cotton or linen. Organic crops are grown using less hazardous pest control methods.
Biocides can also be used during manufacture, transportation or to give the end product antibacterial properties. Mould inhibitors may be used to provide protection during transportation or storage of wet goods. Biocides can often be substituted by changing storage and transportation routines, and the usefulness of having biocides in textile products (e.g. to prevent odours) is heavily debated, especially since the antibacterial treatment is normally rapidly washed out during usage and can give rise to antibiotic resistant bacteria.
Another aspect to consider is that mould protection can affect the working environment. It is very easy to contaminate the areas where warehouse and store personnel unpack clothing and textiles, since the hazardous substances are released when plastics and other packaging are unwrapped.
Hazardous pesticides include atrazine, mirex and DDT. Problematic biocides that may be used in final textile products are triclosan and nano-silver.
These are used to give a desired colour, or whiteness. Some frequently used dyeing methods are using dyes in excess quantities, and large amounts are hence discharged into the wastewater. Some dyes, including azo dyes, can be very toxic and are often persistent, which is a desired property on the fabric but not in the environment. Dyes may also contain heavy metals such as lead or cadmium, which are very hazardous. Optical whiteners on cotton are often only loosely bound to the fibre and hence easily washed off.
From an environmental aspect, it is important to choose dyestuff of quality that binds or adheres strongly to the fibre under optimal production conditions. You should be able to reproduce the process and get the same result over and over again. This also counts for the washing fastness which is a very much wanted desired property for the consumer.
Flame retardants are used to make a product less flammable. Depending on national regulations, flame retardants may be required in a product. Examples of such products are protective clothing, curtains and fabrics used in furniture, to name a few. Some of the currently used flame retardants, especially halogenated versions, have been shown to have hazardous properties and some are subject to international and/or national regulations. The first choice when looking for alternatives is to investigate whether the use of a flame retardant is really required or necessary for the purpose. If it is necessary, you may want to look for an alternative, less flammable material or a combination of materials that fulfills the requirements for your product. The good news is that more and more flame retardants with improved health and environmental profiles are becoming available.
Plasticisers and phthalates
Plasticisers are used to soften plastics. For textile applications, such as screen printing and coating of fabrics, PVC first needs to be softened. One common group of plasticisers is phthalates which are being used in large quantities in the print, often around 30-60% of the total composition. Several phthalates have hazardous properties, such as being toxic to reproduction. Because phthalates are not chemically bound to the PVC but can leach out, users are likely to be exposed to and ingest the phthalates from the textile, for example through fiber dust. Children can get exposed when chewing on the printed textile. More and more brands are trying to use less phthalates in their products. Alternative plasticisers exist, as well as alternatives to PVC.