**4. Antibacterial agents used in the textile industry**

The most common antimicrobial substances used to give textile materials antimicrobial properties are quaternary ammonium compounds (QAC), polyhexamethylene biguanide (PHMB), chitosan, regenerated N-halamine compounds, peroxy acids, metal/metal salts, and triclosan. In addition, there are antimicrobial-enabled paints (e.g., metallic paints) that allow simultaneous dyeing and antimicrobial finishing processes [25]. The chapter is about metal-based antimicrobial finishing and triclosan-based antimicrobial finishing.

#### **4.1 Metal-based antimicrobial finishing**

Many heavy metals are toxic to microorganisms, both freely and in compounds, even at very low concentrations. Other heavy metals such as copper, zinc, and cobalt are also used in the production of antimicrobial textiles, but the most preferred are silver and silver compounds for this purpose [17, 29, 30]. In recent years, the nano-forms of metal and metal compounds have attracted attention as new generation biocides [30]. According to 2018 data, the most commonly used antimicrobial substances in the production of antimicrobial medical textiles are metal/metal salts (39.6%) [31]. The most commonly used metallic salts are silver,

**27**

*The Waste Problem of Antimicrobial Finishing DOI: http://dx.doi.org/10.5772/intechopen.91863*

to exceed \$3.3 billion in 2024 [34].

ensure washing durability [30].

salts (Ag+

production [29].

amount of metal/metal salt on the fiber [29].

*4.1.1 Silver-based antimicrobial finishing*

and there is no toxicity in low concentrations [35–37].

antibiotic-resistant bacteria are used [35].

copper, zinc, and cobalt [31–33]. The global nano-silver market volume is estimated

In synthetic fibers, metal and metal compounds can be added to the environ-

The application of metals to natural fibers can only be done during the finishing process. Various strategies have been developed to improve binding and durability. Cotton was pre-treated with succinct acid anhydrites. Succinic acid anhydride acts as a ligand (atom, molecule, or ion attached to the central atom) for metal ions and provides very effective antibacterial activity by increasing the retention of metal

 and Cu2+) on the surface. In protein fibers (e.g., wool), aspartyl and glutamyl residues are thought to be binding groups for free carboxyl groups, most likely metal ions. Binding capacity can be further increased with EDTA with the ability to skip the tannin acid or metal ions that increase the serious restrictions due to technical and environmental problems; therefore, it is not accepted in commercial

Silver has been used in many areas for centuries as a broad-spectrum antimicrobial substance with antibacterial, antifungal, and antiviral properties. Metallic silver, silver nitrate, and silver sulfadiazine forms have been used for many years to treat burns, wounds, and numerous bacterial infections [35]. Most metal ions are also known to have antimicrobial properties, but silver is best effective against bacteria, viruses, and other eukaryotic microorganisms [35]. Silver has very important advantages as an antibacterial substance. These benefits include the fact that silver is a very broad-spectrum antibiotic and has almost no bacterial resistance to silver,

It is known that the use of silver in the treatment of burns and chronic ulcers in water disinfection dates back to the 1000 BC. In the literature, it is mentioned that silver was used as an eye drop in the 1800s, and then its used was reduced with the presence of penicillin, but 0.5% silver nitrate solution in the 1960s was widely used in burn treatment. In these years, silver's effectiveness against bacteria such as *Staphylococcus aureus*, *Pseudomonas aeruginosa*, and *Escherichia coli* has been proven. In 1968, silver sulfadiazine cream was obtained by combining silver nitrate with sulfonamide. This cream has been widely used in the treatment of burns due to its effectiveness against many microorganisms. The literature states that silver sulfadiazine is active against bacteria such as *E. coli*, *S. aureus*, *Klossiella* sp., and *Pseudomonas* sp. and also has antifungal and antiviral activities [35]. 1% silver nitrate solution is still used as eye antiseptic for various purposes in newborn babies [38]. Today, wound dresses containing different amounts of silver against

Concentrations greater than 0.5% are not generally preferred in silver solutions used for medical purposes. In these concentrations, silver allergy is not reported.

ment before fiber extraction or in the polymer stage before electrospinning and nano-fiber production. During its lifetime, metal ions are released causing biocidal effects in the presence of moisture. The amount of metal ion released varies depending on the chemical structure of the fiber, its surface feature, and the

Metal and metal compounds cause oxidative stress in the microorganism, causing damage to microorganism lipid, protein, and DNA, resulting death [30]. The mechanism of action of the nano-forms of metal/metal compounds is similar. Silica such as zeolite, polymer matrixes, and various cross linking agents are used to stabilize nanoparticles in the structure, to provide controlled oscillation, and to

#### *The Waste Problem of Antimicrobial Finishing DOI: http://dx.doi.org/10.5772/intechopen.91863*

*Waste in Textile and Leather Sectors*

products against mold [27].

and survival.

membrane function.

and proliferation of the cell.

and triclosan-based antimicrobial finishing.

**4.1 Metal-based antimicrobial finishing**

proliferation [27].

fabric [27].

layers or coatings that are simply resistant to the passage of microorganisms into fabric or (b) layers or coatings with direct surface contact effect against microbial

Fire, water, weather, and mildew resistant (FWWMR) end process is an example of obstacle coating. In this process, fabrics are coated with a mixture of organic and anorganic compounds containing fungicide. The blocking or blocking mechanism has been used to protect fabrics from mold yeast and decaying fungi with resin applications or chemical modification of cellulose with cyanoetylation or acetylation. When the finishing process containing flame-retardent agents and resins forms of finishing agent with covalent bonds, they are the most effective

The product of the only antibacterial finishing process based directly on the concept of surface contact attachment obstruction is an organosilicon polymer containing hanging quaternary ammonium groups that form a biobarrier in the

Most of the antimicrobial agents used to manufacture commercial textiles have biocidal effects, but they show activity on microorganism in different ways [17]:

• They damage or inhibit the synthesis of the cell wall, which is critical for life

• They damage intracellular and non-cell matter transport by inhibiting cell

• They cause the death of the microorganism by inhibiting the synthesis of the

• By inhibiting nucleic acid (DNA and RNA) synthesis, they prevent the survival

• By inhibiting metabolic processes, they cause the death of the microorganism.

The most common antimicrobial substances used to give textile materials antimicrobial properties are quaternary ammonium compounds (QAC), polyhexamethylene biguanide (PHMB), chitosan, regenerated N-halamine compounds, peroxy acids, metal/metal salts, and triclosan. In addition, there are antimicrobial-enabled paints (e.g., metallic paints) that allow simultaneous dyeing and antimicrobial finishing processes [25]. The chapter is about metal-based antimicrobial finishing

Many heavy metals are toxic to microorganisms, both freely and in compounds,

even at very low concentrations. Other heavy metals such as copper, zinc, and cobalt are also used in the production of antimicrobial textiles, but the most preferred are silver and silver compounds for this purpose [17, 29, 30]. In recent years, the nano-forms of metal and metal compounds have attracted attention as new generation biocides [30]. According to 2018 data, the most commonly used antimicrobial substances in the production of antimicrobial medical textiles are metal/metal salts (39.6%) [31]. The most commonly used metallic salts are silver,

proteins that make up the building rocks of the cell and enzymes.

**4. Antibacterial agents used in the textile industry**

**26**

copper, zinc, and cobalt [31–33]. The global nano-silver market volume is estimated to exceed \$3.3 billion in 2024 [34].

Metal and metal compounds cause oxidative stress in the microorganism, causing damage to microorganism lipid, protein, and DNA, resulting death [30]. The mechanism of action of the nano-forms of metal/metal compounds is similar. Silica such as zeolite, polymer matrixes, and various cross linking agents are used to stabilize nanoparticles in the structure, to provide controlled oscillation, and to ensure washing durability [30].

In synthetic fibers, metal and metal compounds can be added to the environment before fiber extraction or in the polymer stage before electrospinning and nano-fiber production. During its lifetime, metal ions are released causing biocidal effects in the presence of moisture. The amount of metal ion released varies depending on the chemical structure of the fiber, its surface feature, and the amount of metal/metal salt on the fiber [29].

The application of metals to natural fibers can only be done during the finishing process. Various strategies have been developed to improve binding and durability. Cotton was pre-treated with succinct acid anhydrites. Succinic acid anhydride acts as a ligand (atom, molecule, or ion attached to the central atom) for metal ions and provides very effective antibacterial activity by increasing the retention of metal salts (Ag+ and Cu2+) on the surface. In protein fibers (e.g., wool), aspartyl and glutamyl residues are thought to be binding groups for free carboxyl groups, most likely metal ions. Binding capacity can be further increased with EDTA with the ability to skip the tannin acid or metal ions that increase the serious restrictions due to technical and environmental problems; therefore, it is not accepted in commercial production [29].

### *4.1.1 Silver-based antimicrobial finishing*

Silver has been used in many areas for centuries as a broad-spectrum antimicrobial substance with antibacterial, antifungal, and antiviral properties. Metallic silver, silver nitrate, and silver sulfadiazine forms have been used for many years to treat burns, wounds, and numerous bacterial infections [35]. Most metal ions are also known to have antimicrobial properties, but silver is best effective against bacteria, viruses, and other eukaryotic microorganisms [35]. Silver has very important advantages as an antibacterial substance. These benefits include the fact that silver is a very broad-spectrum antibiotic and has almost no bacterial resistance to silver, and there is no toxicity in low concentrations [35–37].

It is known that the use of silver in the treatment of burns and chronic ulcers in water disinfection dates back to the 1000 BC. In the literature, it is mentioned that silver was used as an eye drop in the 1800s, and then its used was reduced with the presence of penicillin, but 0.5% silver nitrate solution in the 1960s was widely used in burn treatment. In these years, silver's effectiveness against bacteria such as *Staphylococcus aureus*, *Pseudomonas aeruginosa*, and *Escherichia coli* has been proven. In 1968, silver sulfadiazine cream was obtained by combining silver nitrate with sulfonamide. This cream has been widely used in the treatment of burns due to its effectiveness against many microorganisms. The literature states that silver sulfadiazine is active against bacteria such as *E. coli*, *S. aureus*, *Klossiella* sp., and *Pseudomonas* sp. and also has antifungal and antiviral activities [35]. 1% silver nitrate solution is still used as eye antiseptic for various purposes in newborn babies [38]. Today, wound dresses containing different amounts of silver against antibiotic-resistant bacteria are used [35].

Concentrations greater than 0.5% are not generally preferred in silver solutions used for medical purposes. In these concentrations, silver allergy is not reported.

However, when using wound dress containing a high amount of silver ion in large wounds, a disease called argyrism can be found in the form of bluish and brown lesions in the skin and mucous membrane. This disease causes the removal of silver ions from the open wound for a long time [35, 39].

Metallic silver is actually inert, but when it comes into contact with the skin, the moisture and fluid of the wound on the skin make it ionized. Iodine silver is highly reactive. It connects to tissue proteins, causing structural changes in the bacterial cell wall and then the nuclear membrane, causing the death of the microorganism [35].

#### *4.1.2 Mechanism and toxicity of silver*

The mechanism of killing microorganisms by silver is still not very clear. The mechanism was attempted to be clearer by examining morphological and structural changes caused by metallic silver, silver ions, and silver nanoparticles in the bacterial cell. In light of the studies, it is known that silver is connected to the bacterial cell wall and cell membrane, interacting with thiol groups to inhibit respiratory enzymes, thus leading to the death of the microorganism [35, 36].

Liau and his colleagues studied the effect of silver ions on amino acids containing thiol (–SH) groups in 1997 [40].

A 2000 study by Feng and colleagues examined the morphological changes that silver ions have on gram-positive *S. aureus* and gram-negative *E. coli* bacteria. AgNO3 was used as an ion source in the study. Gram-positive *S. aureus* has been shown to be able to better resist silver ions due to its thick cell wall, which is typical of positive bacteria. Again, the study reported that DNA, which can only be copied while free, has become a more intense form within the cell, which shows that DNA has lost its ability to copy itself [41].

In his 2005 study, Holt and colleagues reported that the increase in the amount of potassium in the environment was detoxicated by the toxicity of silver against microorganisms [42].

Li and colleagues studied the antibacterial effect mechanism of silver nanoparticles on *E. coli* in a 2010 study. In this study, silver nanoparticles first disrupted the structure of the cell membrane and entered the cell and then inhibited the respiratory enzymes by relocating the hydrogen atoms (–S–Ag–) in the cysteine thiol (–SH) groups. The development and proliferation of bacteria stop if cell member permeability and respiratory of cell deteriorate [43].

Many studies are being conducted on the antimicrobial mechanism of nanosilver particles, but there is not enough work on toxicity. A limited number of studies conducted in in vitro conditions show that nano-silver particles are much more toxic than conventional silver and other heavy metals [35, 44]. Shapes, particle sizes, crystalline, surface properties, ambient humidity, ambient pH, cations in the environment, and their concentrations are among the particles that affect the toxicity of silver nanoparticles [45]. In vitro studies reveal that nano-silver particles cause damage to the brain, liver, and reproductive cells in mammals. In 1999, the FDA warned that the use of colloidal silver solutions containing microor nanoparticles could lead to neurological problems, headaches, skin irritation, weakness, stomach ailments, and kidney ailments. It is also reported that silver nanoparticles will affect rivers, lakes, and all living things that make up the ecosystem by blending into the food chain by mixing into the water. Washing machines produced in recent years, using nano-silver technology, are also objectionable in this context. In order to further clarify this issue, a large number of independent animal and clinical trials that are not supported by producers must be performed [35, 43, 46].

**29**

*The Waste Problem of Antimicrobial Finishing DOI: http://dx.doi.org/10.5772/intechopen.91863*

powder form) [35–37].

in this region [31].

**4.2 Triclosan-based antimicrobial finishing**

away from textile materials [57].

*4.1.3 Silver contaminated waste and silver accumulation*

effect on all living organisms and reach the food chain [14, 35].

Silver and its different forms are wide spectrum antibiotics. They have low risk of bacterial resistance, and their low concentrations are not toxic, and they have ease of application and low cost. Because of these advantages, silver and other forms of it are widely used in most areas and surfaces, which are being antimicrobial desired. It is also widely used in the production of antimicrobial textiles in different forms of Ag and silver (colloidal silver, silver salts, and elemental silver in

Ag particles are applied to the textile surface using binder or cross-binding substances; it is possible to increase washing resistance. However, as a result of washing both during antimicrobial textile production and throughout its life cycle, most of the Ag particles on the textile surface mix into rivers, lakes, and groundwater along with wastewater, causing the accumulation of silver in the ecosystem. Disposable hygiene products are a similar situation [36]. Most antimicrobial textile products are released into washing water for 50% of the amount of silver at the end of three washings. And the textile products release 10–98% content of the silver into washing water at the end of 10 washings [47]. According to a study, up to 75% of silver may be released from textiles impregnated with Ag NPs in one washing cycle [48]. It is clear that silver accumulated in the ecosystem, water or soil, will have a toxic

According to a study conducted in 64 countries on the release of silver from different products into nature, the United States is the country that releases the most silver into the environment, globally. The Asian continent is the continent which has the most silver emissions directly into the aquatic environment and land [49]. According to a report, 68% of the global silver consumption is used for water treatment and 32% for other uses. And 3.4–40 metric tons of silver are used in textiles per year [5]. In the United States, 29% of the silver used in different industries is released into the aquatic environment, and 69% are known to be dumped in solid waste storage [50]. In recent years nano-silver consumption in textiles like other industries has been increasing rapidly also [51]. The regions where antimicrobial medical textiles containing metallic salts such as copper, zinc, cobalt, mainly silver most used are North America (39% of market volume), Europe (23% of market volume), the Asia Pacific regions (30% of market volume) and the rest of the world (7% of the market volume) respectively [31, 48]. The highest use rate belongs to North America because hospital infection and cardiovascular disease rates are high

Triclosan has been widely used in commercial products for many years as an antimicrobial substance used in soaps, deodorants, cosmetics, cleaning lotions, plastics, toothpastes, and antibacterial textiles [52–56]. The European Union's consumption of triclosan in 2006 is reported to be approximately 450 tons. It is reported that 85% of this is used in personal care products, 5% in textile products, and 10% in plastics and products that come into contact with food [54, 57]. Triclosan is also frequently used in the textile industry. Triclosan is used to prevent the formation of bad odor in wool; to prevent the reproduction of bacteria and fungi in synthetic, mixtures, and non-woven textile materials; and to keep mites

75–210 metric tons of triclosan are used in textiles per year globally [5]. According to a 2009 report by the Australian government, between 2001 and 2005, the amount of triclosan contained in textile products exported to Australia varied

*Waste in Textile and Leather Sectors*

microorganism [35].

*4.1.2 Mechanism and toxicity of silver*

ing thiol (–SH) groups in 1997 [40].

has lost its ability to copy itself [41].

permeability and respiratory of cell deteriorate [43].

microorganisms [42].

ions from the open wound for a long time [35, 39].

However, when using wound dress containing a high amount of silver ion in large wounds, a disease called argyrism can be found in the form of bluish and brown lesions in the skin and mucous membrane. This disease causes the removal of silver

Metallic silver is actually inert, but when it comes into contact with the skin, the moisture and fluid of the wound on the skin make it ionized. Iodine silver is highly reactive. It connects to tissue proteins, causing structural changes in the bacterial cell wall and then the nuclear membrane, causing the death of the

The mechanism of killing microorganisms by silver is still not very clear. The mechanism was attempted to be clearer by examining morphological and structural changes caused by metallic silver, silver ions, and silver nanoparticles in the bacterial cell. In light of the studies, it is known that silver is connected to the bacterial cell wall and cell membrane, interacting with thiol groups to inhibit respiratory

Liau and his colleagues studied the effect of silver ions on amino acids contain-

In his 2005 study, Holt and colleagues reported that the increase in the amount of potassium in the environment was detoxicated by the toxicity of silver against

Li and colleagues studied the antibacterial effect mechanism of silver nanoparticles on *E. coli* in a 2010 study. In this study, silver nanoparticles first disrupted the structure of the cell membrane and entered the cell and then inhibited the respiratory enzymes by relocating the hydrogen atoms (–S–Ag–) in the cysteine thiol (–SH) groups. The development and proliferation of bacteria stop if cell member

Many studies are being conducted on the antimicrobial mechanism of nanosilver particles, but there is not enough work on toxicity. A limited number of studies conducted in in vitro conditions show that nano-silver particles are much more toxic than conventional silver and other heavy metals [35, 44]. Shapes, particle sizes, crystalline, surface properties, ambient humidity, ambient pH, cations in the environment, and their concentrations are among the particles that affect the toxicity of silver nanoparticles [45]. In vitro studies reveal that nano-silver particles cause damage to the brain, liver, and reproductive cells in mammals. In 1999, the FDA warned that the use of colloidal silver solutions containing microor nanoparticles could lead to neurological problems, headaches, skin irritation, weakness, stomach ailments, and kidney ailments. It is also reported that silver nanoparticles will affect rivers, lakes, and all living things that make up the ecosystem by blending into the food chain by mixing into the water. Washing machines produced in recent years, using nano-silver technology, are also objectionable in this context. In order to further clarify this issue, a large number of independent animal and clinical trials that are not supported by producers must be performed

A 2000 study by Feng and colleagues examined the morphological changes that silver ions have on gram-positive *S. aureus* and gram-negative *E. coli* bacteria. AgNO3 was used as an ion source in the study. Gram-positive *S. aureus* has been shown to be able to better resist silver ions due to its thick cell wall, which is typical of positive bacteria. Again, the study reported that DNA, which can only be copied while free, has become a more intense form within the cell, which shows that DNA

enzymes, thus leading to the death of the microorganism [35, 36].

**28**

[35, 43, 46].
