Establishing a New International Standard for Natural Dyed Textile Goods [Natural Organic Dye Standard (NODS)]

ABSTRACT Environmental awareness has become more important among individuals and societies in recent years. The increasing awareness and sensitivity to the environment have made the reintroduction of natural dyes in the textile industries even more important. To date, natural dyes have been employed in the textile industries for years, and their use is now increasing rapidly. However, there is no standard or no criteria for textiles colored with natural dyes despite the fact that individual and institutional customers, textile brands, and other bodies have been advocating for such as standards. For this reason, NODS (Natural Organic Dye Standard) is required like GOTS (Global Organic Textile Standard), OECO-TEX (International Association for Research and Testing in the Field of Textile and Leather Ecology), and other certificates. The NODS includes a list of natural dye resources (dye plants, dye insects, dye mollusks, dye lichens, and dye fungi), natural coloring compounds, mordant materials, auxiliary substances, and index of fastness properties of dyes used in textiles, and list of prohibited, and restricted substances. The standards also specify test and analysis methods.

RCS (Recycled Claim Standard) and GRS (Global Recycled Standard) are international, voluntary standards that set requirements for third-party certification of recycled input and chain of custody. The shared goal of the standards is to increase the use of recycled materials. The GRS includes additional criteria for social and environmental processing requirements and chemical restrictions (https://textileexchange.org/standards/recycled).
The desire to control bacteria, fungi, mold, and algae and eliminate some human health problems, damage, stains, smells, and some materials that have been antimicrobial modified increased considerably in recent years. Biocidal products used to treat various textile materials are designed to neutralize and prevent the action or to exercise effective control on the development of any harmful organism in chemical or biological ways. At the same time, biocides may manifest harmful effects on humans, and animals. Biocides are used to maintain textiles in good hygienic conditions to avoid mold formation and deterioration. Biocidal products are regulated and the use of biocides is restricted. Residue tests are analyzed according to ISO 17,025. Pesticides, fertilizers used during the cultivation of natural fibers (e.g. cotton), and pesticides do not decompose until final use in humans. They increase toxic substances. This harms the reproductive, hormonal, and immune systems of humans.
Heavy metals such as arsenic, lead, cadmium, cobalt, chromium, nickel, copper, and mercury can be found in dyestuffs used in coloring.
PFOS (perfluorooctane sulfonate), PFOA (perfluorooctanoic acid), and Teflon (Fluoro Carbon) have been used because of their heat-resistant, water, and oil-repellent properties in textile, leather, and paper coating, dyeing (Hou et al. 2022). But these substances have carcinogenic effects and their use was restricted or prohibited.
There are many academic studies on using natural dyes in the textile industry. The number of these studies has been increasing rapidly in recent years (Alkan, Torgan, and Karadag 2017;Baaka 2020;Guzel and Karadag 2021;Guzel, Karadag, and Alkan 2020). There are many methods and many different recipe studies in the dyeing of protein and cellulose-based fibers with natural dyes (Karadag 2022(Karadag , 2023Ozdemir and Karadag 2023;Karadag and Yildiz 2022;Karadag, Buyukakinci, and Guzel 2022).
Sustainability, awareness, and properties of natural dyes are especially important to environmentally sensitive and conscious consumers, as interest in textile products dyed with natural dyes has grown in recent years. Many textile industries are using natural dyes in some of their production to meet the demands of their customers. Some textile companies continue their R&D studies for mass production with natural dyeing. Yet, there is no standard to check that a textile product has been dyed with natural dye. Thus, it is necessary to establish the NODS (Natural Organic Dye Standard) The NODS aims to define particular requirements to ensure the natural dye status of textiles, from raw materials to environmentally and sustainably responsible manufacturing to provide credible assurance to the end consumer.

Dye plants
The vast majority of natural dye raw materials are dye plants. The roots, stems, branches, and flowers or whole parts of certain plants are utilized in natural dyeings. The main coloring compounds (dyestuffs) of the dye plants are anthraquinones, flavonoids, anthocyanins, carotenoids, indigoids, and tannins, as outlined in these dyestuffs resources books (Böhmer et al. Cardon 2007;Karadag 2007;Schweppe 1992) and many publications (Baliarsingh et al. 2012;Petroviciua et al. 2012;Shahid, Islam, and Mohammad 2013). The NODS includes 1546 dye plants (Table 1).

Dye molluscs
The purple color was obtained from dye mollusks. The purple dye extracted from mollusks has historically been considered a luxurious color and evidence of its first use has been found around the Mediterranean basin. The color has been known as Imperial and Royal purple since ancient times. The dye mollusks include indigoid coloring compounds, as contained in many books (Böhmer et al. 2002;Cardon 2007;Karadag 2007;Schweppe 1992) and many publications (Karapanagiotis et al. 2007;Reese 2008). The standard includes 12 dye mollusks (Table 3).

Dye lichens
Several dyes have been obtained from lichens, and the use of lichens to produce dyes has a long history. Lichens form a group comprising of more peculiar natural colorants in dyeing violet and purple colors that have been widely used in Europe and other parts of the world since ancient times up until the beginning of the Middle Ages. The standard includes mainly 46 dye lichens (Cardon 2007;Schweppe 1992) as do many publications (Raisanen 2009;Shaheen, Iqbal, and Hussain 2018) (Table 4).

Dye fungi
Fungi occupy a unique place in the history of dyeing. The fungi class of organisms previously considered part of the plant kingdom, is now recognized as a separate kingdom, distinct from both plants and animals. Most fungi produce pigments that are water-soluble and ideal for industrial production since they can be easily to scaled up in industrial fermenters and extracted without the use of organic solvents (Venil et al. 2020). The standard includes 72 dye fungi (Cardon 2007;Schweppe 1992) as do many publications (Venil et al. 2020) (Table 5).

Fastness
The color fastness property of textile materials, especially fabric is very important for processing and use. It is the ability to withstand the reduction of color from the surface of textile materials when undergoing different processes and treatments. The response of the color fastness property to washing, light, rubbing, and sweat fastness (alkaline and acidic) of the dyed goods was determined according to ISO 105 C06 A1 M, ISO 105 B02, ISO 105 × 12, and ISO 105 E04, respectively (Table 7).

Prohibited and restricted substances
Prohibited and restricted substances in the GOTS (Global Organic Textile Standard) were prohibited and restricted by the NODS (Natural Organic Dye Standard) (Tables 8-12). Synthetic coloring compounds (dyestuffs) and synthetic binders are also prohibited under GOTS standards (https://global-standard.org/). In addition, list of restricted substances in finished products, major risk areas in the textile supply chain, and the importance of manufacturing restricted substances were given (Gobalakrishnan, Das, and Saravanan 2021).

Result and discussion
NODS was set as a standard after the needs of the textile industries and the demand of customers. Numerous published articles (Deveogl and Karadag 2019;Şahinbaşkan, Karadag, and Torgan 2018) and books (Böhmer et al. 2002;Cardon 2007;Karadag 2007;Raisanen 2009;Schweppe 1992) about natural dyes and natural coloring compounds have been published in the last thirty years. NODS includes natural dyes/coloring compounds found in textile goods (Tables 1-6). It rates the fastness of natural dyes lower than of synthetic dyes in cellulosebased fibers or fabrics. For this reason, it has been assumed that the fastness of natural dyes is moderate. However, the fastness values are sufficient for the textile companies using them for natural dyed textiles goods (Table 7). Heavy metals and substances that are restricted, prohibited, and limited to use in textile products according to GOTS standards were also restricted, prohibited, and limited uses in NODS standards (Tables 8-10). Free mordant metals and some free elements were given in the NODS (Table 11). All synthetic dyestuff groups and all synthetic binder groups contained in the textile product were prohibited in the NODS (Table 12).

Conclusion
Quality, sustainability, eco-friendly, awareness, ZHCD, GOTS, and other criteria now outweigh price as the prime consideration for customers. Natural dye resources and natural coloring compounds (dyestuffs) are increasingly used in high-volume textile production industries (Karadag 2022(Karadag , 2023. With both consumer and brand demand, it has become a necessity set a standard (NODS) in the dyed textile products for natural dyes as well as the other desirable standards for textile products. NODS criteria are also requested in the natural dyed productions. To respond to this demand, the articles have developed criteria for NODS based on previous research. When purchasing textiles that follow the NODS, the consumers can be sure that the goods are colored with natural dye and will be able to use them with confidence. Brands and textile industries that produce according to the NODS will be earning more while contributing to sustainability and eco-friendly dyeings.
By its nature, the NODS does not include dangerous substances, heavy metals, toxic dyes, carcinogenic substances, pesticides, and synthetic dyes.
Following new developed in technology and materials, and responding to new customer demands, and to new analysis methods, engineers and chemists are constantly improving and refining standards such as GOTS, OECO-TEX, ZDHC, and others. For similar reasons, new versions of NODS will also respond to changes in science. NODS creates important and timely new standards for the textile industry. It is created exclusively for textiles that use natural dyes and is not suitable for synthetic materials or synthetic dyes. The image of the NODS standard was designed as above the title.
• One of the most important issues of recent years is the Zero Discharge of Hazardous Chemicals (ZDHC) concept in textile dyeing and goods. It is known that natural dye is the most suitable method for the criteria of ZDCH and this dyeing is encouraged in the textile dyeings by important textile companies. • All dye plants, dye insects, and dye mollusks were given used in the natural dyeings in the manuscript.
• Fastness tests were given in the manuscript. • NODS is demanded by the textile industries and their customers.