Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP Environmental, Health, and Safety Guidelines for Textile Manufacturing Introduction taken into account. The applicability of specific technical recommendations should be based on the professional opinion The Environmental, Health, and Safety (EHS) Guidelines are of qualified and experienced persons. technical reference documents with general and industry- specific examples of Good International Industry Practice When host country regulations differ from the levels and (GIIP) 1. When one or more members of the World Bank Group measures presented in the EHS Guidelines, projects are are involved in a project, these EHS Guidelines are applied as expected to achieve whichever is more stringent. If less required by their respective policies and standards. These stringent levels or measures than those provided in these EHS industry sector EHS guidelines are designed to be used Guidelines are appropriate, in view of specific project together with the General EHS Guidelines document, which circumstances, a full and detailed justification for any proposed provides guidance to users on common EHS issues potentially alternatives is needed as part of the site-specific environmental applicable to all industry sectors. For complex projects, use of assessment. This justification should demonstrate that the multiple industry-sector guidelines may be necessary. A choice for any alternate performance levels is protective of complete list of industry-sector guidelines can be found at: human health and the environment. www.ifc.org/ifcext/enviro.nsf/Content/EnvironmentalGuidelines Applicability The EHS Guidelines contain the performance levels and The EHS Guidelines for Textile Manufacturing include measures that are generally considered to be achievable in new facilities by existing technology at reasonable costs. Application information relevant to textile manufacturing projects and facilities for natural fibers, synthetic fibers (made entirely from of the EHS Guidelines to existing facilities may involve the chemicals), and regenerated fibers (made from natural materials establishment of site-specific targets, with an appropriate by processing these materials to form a fiber structure). This timetable for achieving them. document does not include polymer synthesis and natural raw The applicability of the EHS Guidelines should be tailored to materials production. Annex A contains a full description of the hazards and risks established for each project on the basis industry activities for this sector. of the results of an environmental assessment in which site- This document is organized according to the following sections: specific variables, such as host country context, assimilative capacity of the environment, and other project factors, are Section 1.0 — Industry-Specific Impacts and Management Section 2.0 — Performance Indicators and Monitoring 1 Defined as the exercise of professional skill, diligence, prudence and foresight Section 3.0 — References that would be reasonably expected from skilled and experienced professionals engaged in the same type of undertaking under the same or similar Annex A — General Description of Industry Activities circumstances globally. The circumstances that skilled and experienced professionals may find when evaluating the range of pollution prevention and control techniques available to a project may include, but are not limited to, varying levels of environmental degradation and environmental assimilative capacity as well as varying levels of financial and technical feasibility. APRIL 30, 2007 1 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP 1.0 Industry-Specific Impacts less hazardous compounds or process modifications that allow removal of iron and alkaline cations); and Management • The use of non-permanent flame retardants and cross- The following section provides a summary of EHS issues linking agents with high formaldehyde levels should be associated with textiles manufacturing, which occur during the avoided; operational phase, along with recommendations for their • Toxic and persistent organic and inorganic textile management. Recommendations for the management of EHS preservation chemicals (e.g. brominated and chlorinated issues common to most large industrial facilities during the compounds, dieldrin, arsenic, and mercury) used in construction and decommissioning phases are provided in the mothproofing, carpet bicking, and other finishing General EHS Guidelines. processes, should be replaced with biodegradable agents; 1.1 Environment • The use of potentially impacting antifoaming agents should be avoided or minimized, through recycling, preventing Environmental issues during the operational phase of textile fabric rotation, or selecting biodegradable / bioeliminable manufacturing primarily include the following: agents. • Hazardous materials management The following chemicals should be avoided: • Wastewater • Emissions to air • Chemicals prohibited by the Oeko-Tex Standard 1000,2; • Energy consumption • Heavy benzene compounds used in emulsion • Solid and liquid waste concentrations of the pigment print process; • Dichromates as oxidizing agents, unless replacement is not possible due to fabric characteristics and color fastness Hazardous Materials Management requirements; Chemical Selection and Use • Chlorinated and fluorochlorinated solvents in open Textile manufacturing activities may include the use of systems. hazardous chemicals in pretreatment, dyeing, and other processes to provide the final product with desired visual and Wastewater functional properties. Recommendations to avoid or, where avoidance is not possible, to minimize the use of hazardous Industrial Process Wastewater materials include the following: Industry-specific wastewater effluents are related to wet operations, which are conducted during different parts of the • Potentially hazardous surfactants should be replaced with textile manufacturing process. Process wastewater from textile biodegradable / bioeliminable compounds that do not manufacturing is typically alkaline and has high BOD (from 700 generate potentially toxic metabolites; to 2,000 mg/l) and COD loads. Pollutants in textile effluents • The use of non-biodegradable and bioeliminable tensides and complexing agents in pretreatment and dyeing 2The prohibited chemicals are listed in Section 6.2.1 of the Oeko-Tex processes should be avoided (e.g. through the selection of Association Standard 1000 (Oeko-Tex Association, 2006c).. APRIL 30, 2007 2 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP include suspended solids, mineral oils (e.g. antifoaming agents, • Use of readily biodegradable detergents / surfactants that grease, spinning lubricants, non-biodegradable or low- do not give rise to toxic metabolites. (e.g. APEO should be biodegradable surfactants [alkylphenol ethoxylates APEO, replaced with alcohol ethoxylates); nonylphenol ethoxylates], and other organic compounds, • Optimization of mechanical removal of water prior to the including phenols from wet finishing processes (e.g. dyeing), drying process; and halogenated organics from solvent use in bleaching. • Adoption of low volatile organic compound (VOC) emitting Effluent streams from dyeing processes are typically hot and solvent wash for removal of water insoluble oils. colored and may contain significant concentrations of heavy metals (e.g. chromium, copper, zinc, lead, or nickel). For water-based wool scouring, dirt removal / grease recovery loops lead to low water consumption (2-4 l / kg of greasy wool) Industrial process wastewater from natural fiber processing may and a reduction of organic load in the effluent. contain pesticides used in prefinishing processes (e.g. cotton growing and animal fiber production), potential microbiological Water temperature control (optimum at 65° C) and dryer pollutants (e.g. bacteria, fungi, and other pathogens), and other automatic humidity control using sensors typically leads to contaminants (e.g. sheep marking dye, tar). This is particularly energy reduction. significant for animal fiber processing. Recommendations for the Wool scouring using organic solvents leads to low energy management of specific wastewater streams in textile consumption and an almost complete removal of pesticides from manufacturing are discussed below. the wool, however, fugitive emissions and water contaminated Scouring : Fiber (especially wool) scouring involves the use of with solvents may be generated and require treatment. hot water and detergents to remove soil, vegetable impurities, Finishing operations : Wet processing or finishing processes grease (lanolin) and d other contaminants from fibers. Wool include the main processes of fabric preparation, namely scouring typically uses water and alkali, although scouring with desizing, bleaching, mercerizing, dyeing, printing, and other an organic solvent is also possible. Scouring with alkali breaks specific treatments. These phases treat fabrics with chemical down natural oils and surfactants and suspends impurities in the and liquor baths and often require several washing, rinsing, and bath. The scouring effluent is strongly alkaline, and a significant drying steps, generating significant wastewater effluents. portion of BOD5 and COD loads from textile manufacturing arises from scouring processes. The recommended pollution The recommended pollution prevention and control techniques prevention and control techniques include the following: for the finishing pretreatment steps include the following: • Design of scouring systems to remove heavy settleable • Selection of water soluble and biodegradable lubricants for solids continuously; increase recovery of wool grease (for knitted fabrics instead of mineral oil and wash them with sale); recover heat from the final facility effluent; and water; control water usage;3 • Use of organic solvent washing for non water soluble lubricants; 3 An example of this approach is the Wool Research Organization of New • The thermofixing step may be performed before the Zealand (WRONZ) Comprehensive Scouring System, which is a modified form of emulsion scouring. washing step. Air emissions generated from the stenter APRIL 30, 2007 3 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP should be treated by dry electrofiltration. The oil separated dioxide gas. Hydrogen peroxide is the most commonly used should be collected to limit effluent contamination; bleaching agent for cotton and is typically used with alkali • Residual liquor should be minimized through reduced solutions. The use of chlorine-based bleaches may produce application, reduced tank volumes and padding liquor organic halogens (due to secondary reactions) and cause recycling; significant concentrations of adsorbable organic halogens • using mechanical dewatering equipment to reduce water (AOX), particularly trichloromethane, in the wastewater. Sodium content of the incoming fabric and reduce energy hypochlorite bleaching represents the most significant concern, consumption in stenter frame. and lower AOX formation should result if sodium chlorite bleaching is used. The wastewater is alkaline. Recommended Desizing : Desizing operations may generate effluents with pollution prevention and control techniques include the significant concentrations of organic matters and solids. BOD5 following: and COD loads from desizing may be significant (35 to 50 percent of the total load), and COD concentrations up to 20,000 • Use of hydrogen peroxide bleaching agent, instead of mg/L may be generated.4 Recommended pollution prevention sulfur- and chlorine-based bleaches; and control techniques include the following: • Reduce the use of sodium hypochlorite6; • Control of stabilizers employed, using biodegradable • Selection of raw material with low add-on techniques (e.g. products where possible and avoiding products with poorly pre-wetting of the warp yarn); bioeliminable complexing agents (e.g. • Selection of more bioeliminable sizing agents (e.g. ethylenediaminetetraacetic acid [EDTA], modified starches, certain galactomannans, polyvinyl diethylenetriaminepentaacetic acid [DTPA]). alcohol, and certain polyacrylates);5 • Application of enzymatic or oxidative desizing with starch Mercerizing : During mercerizing, cotton fiber reacts with a and modified starch sizing agents, followed by washing solution of caustic soda, and a hot-water wash treatment systems; removes the caustic solution from the fiber. The caustic solution • Integration of desizing / scouring and bleaching in a single remaining on the fiber is neutralized with acid, followed by a step to reduce effluent generation (e.g. reuse of bleach number of rinses to remove the acid. Wastewater from rinse water in desizing); mercerizing is highly alkaline, since it contains caustic soda. • Recovery and reuse of specific water-soluble synthetic The recommended pollution prevention and control technique sizing agents (e.g. PVA, polyacrylates, and carboxymethyl involves the recovery and reuse of alkali from mercerizing cellulose) by ultrafiltration. effluent, particularly rinsing water, subject to color limitations that may apply to mercerized cloth woven from dyed yarn. Bleaching: Common bleaching reagents include hydrogen peroxide, sodium hypochlorite, sodium chlorite, and sulfur Dyeing : Wastewater from dyeing may contain color pigments, halogens (especially in vat, disperse, and reactive dyes), metals 4 European Commission, 2003b 6 This agent should be considered only for flax and bast fibers that cannot be 5 The degree of bioelimination should be >80 percent after 7 days based on bleached with hydrogen peroxide. Consider use of a two-step process with a OECD test method 302 B, recommended in the IPPC BREF resource document hydrogen peroxide stage to remove impurities, which would act as a precursor for the textile industry (European Commission, 2003b). for AOX formation, followed by elemental chlorine–free bleaching. APRIL 30, 2007 4 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP (e.g. copper, chromium, zinc, cobalt, and nickel), amines • Conduct dyeing in high temperature conditions without (produced by azo dyes under reducing conditions) in spent carriers; dyes, and other chemicals used as auxiliaries in dye formulation • Replacement of sodium dithionite with reducing agents (e.g. dispersing and antifoaming agents) and in the dyeing based on sulfinic acid derivatives; process (e.g. alkalis, salts, and reducing / oxidizing agents). • Replacement of conventional powder and liquid sulfur dyes Dyeing process effluents are characterized by relatively high with stabilized non-pre-reduced sulfide-free dyestuffs or BOD and COD values, the latter commonly above 5,000 mg/l. with pre-reduced liquid dye formulations with a sulfide Salt concentration (e.g. from reactive dye use) may range content of less than 1 percent; between 2,000 and 3,000 ppm7. The recommended pollution • Adoption of systems and measures capable to allow that prevention and control techniques include the following: only the lowest amount needed of reducing agent is consumed to reduce the dyestuff; • Use of automatic systems for dosing and dispensing dyes; • Use of disperse dyes that can be cleared in alkaline • When applicable, use of continuous and semi-continuous medium by hydrolytic solubilization instead of reduction; dyeing processes to reduce water consumption with • Use of dye formulations that contain highly biodegradable respect to more traditional batch dyeing processes; dispersing agents (e.g. based on fatty acid esters or • Use of bleaching systems (e.g. jet and package dyers and modified aromatic sulfonic acids); pad batch techniques), that reduce liquor-to-fabric ratios; • Substitution of chrome dyes with reactive dyes. Benzidine- • Use of machinery with automatic controllers of temperature based azo dyes, dyes containing heavy metals, and and dyeing cycle parameters; chlorine-based dyes should be avoided. Azo dyes that may • Optimization of machine size related to the size of fabric produce carcinogenic aromatic amines should also be lots processed; avoided; • Implementation of mechanical liquor extraction to reduce • Adoption of low-salt dyeing techniques, especially for dye liquor carryover and improve washing efficiency; reactive dyes; • Adoption of optimized process cycles and procedures to • Adoption of a pH-controlled drying process (use of pH- reduce cycle duration; reuse of rinse water for subsequent controllable acid and basic dyes that allow control of pH); dyeing, or countercurrent rinsing in continuous machines; • Treatment of dyeing wastewater at treatment plants using and reconstitution and reuse of dye bath; commonly available techniques, such as electrolysis, • Substitution of conventional dye carriers and finishing ultrafiltration and reverse osmosis, activated sludge, agents with less toxic compounds based on flocculation, and oxidation/reduction. benzylbenzoate and N-alkylphthalimide. Carriers containing chlorinated organic compounds, phenyls, and Printing: Print paste components consist of color concentrates, biphenyls should be avoided; solvents, and binder resins. Color concentrates contain • Use of non–carrier dyeable polyester fibers; pigments (insoluble particles) or dyes. Organic solvents are used exclusively with pigments. Defoamers and resins are aimed at increasing color fastness. Printing blankets or back 7 Cotton batch dyeing operations typically use quantities of salt ranging from 20 grays (fabric backing material that absorbs excess print paste), to 80 percent of the weight of fabrics dyed. APRIL 30, 2007 5 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP which are washed with water before drying, may generate o Avoid the use of dyeing auxiliaries (e.g. leveling wastewater with an oily appearance and significant volatile agents) that can retard the uptake of mothproofing organic compound (VOC) levels from the solvents (mineral agents. spirits) used in print paste. The recommended pollution prevention and control techniques include the following: Process Wastewater Treatment Since textile manufacturing operations use a myriad of raw • Reduce printing paste losses in rotary screen printing by materials, chemicals and processes, wastewater treatment may minimizing the volume of printing paste supply and by require the use of unit operations specific to the manufacturing recovering and recycling printing paste at the end of each process in use. Techniques for treating industrial process run; wastewater in this sector include source segregation and • Reuse rinsing water leftover from cleaning the printing belt; pretreatment of wastewater streams as follows: (i) high load • Use transfer printing for synthetic fabrics and digital ink-jet (COD) streams containing non-biodegradable compounds using printing machines to produce short runs of fabrics; chemical oxidation, (ii) reduction in heavy metals using chemical • Avoid the use of urea by controlled addition of moisture or precipitation, coagulation and flocculation, etc. and (iii) treatment by two-step printing methods; of highly colored or high TDS streams using reverse osmosis. • Use printing pastes with no or low VOC emissions (e.g., Typical wastewater treatment steps include: grease traps, water-based, APEO-free, and reduced-ammonia-content skimmers or oil water separators for separation of floatable printing pastes). solids; filtration for separation of filterable solids; flow and load equalization; sedimentation for suspended solids reduction Mothproofing : Mothproofing agents can be based on using clarifiers; biological treatment, typically aerobic treatment, permethrin, cyfluthrin and other biocides, which are potentially for reduction of soluble organic matter (BOD); biological nutrient highly toxic compounds to aquatic life. The recommended removal for reduction in nitrogen and phosphorus; chlorination pollution prevention and control techniques include the of effluent when disinfection is required; dewatering and following: disposal of residuals in designated hazardous waste landfills. • Implement handling procedures during dispensing and Additional engineering controls may be required for (i) advanced transport of mothproofing agent concentrates to minimize metals removal using membrane filtration or other spillage within the dyehouse; physical/chemical treatment technologies, (ii) removal of • Implement operating techniques to ensure maximum recalcitrant organics, residual pesticides and halogenated efficiency (transfer of insect resist agent to the fibre) and organics using activated carbon or advanced chemical lowest residues of active substance in the spent dyeing oxidation, (iii) residual color removal using adsorption or liquor and rinse water, such as: chemical oxidation, (iv) reduction in effluent toxicity using o Ensure that a pH value lower than 4.5 is reached at appropriate technology (such as reverse osmosis, ion the end of the process. If this cannot be achieved, the exchange, activated carbon, etc.), (v) reduction in TDS in the insect resist agent should be applied in a separate effluent using reverse osmosis or evaporation, and (vi) step, re-using the bath, containment and neutralization of nuisance odors. APRIL 30, 2007 6 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP Management of industrial wastewater and examples of Emissions to Air treatment approaches are discussed in the General EHS Textile manufacturing operations that may generate significant Guidelines . Through use of these technologies and good sources of air pollutants include the finishing processes (e.g. practice techniques for wastewater management, facilities coating and dyeing operations). Other significant sources of air should meet the Guideline Values for wastewater discharge as emissions in textile operations include drying, printing, fabric indicated in the relevant table of Section 2 of this industry sector preparation, and wastewater treatment residues. Solvents may document. be emitted from coating / treatment finishing processes, drying ovens, and high-temperature drying and curing. Other potential Other Wastewater Streams emissions include formaldehyde, acids (especially acetic acid), Guidance on the management of non-contaminated wastewater and other volatile compounds, such as carriers and solvents, from utility operations, non-contaminated stormwater, and emitted during dyeing operations and from wastewater sanitary sewage is provided in the General EHS Guidelines. treatment operations. Solvent vapors may contain toxic Contaminated streams should be routed to the treatment system compounds such as acetaldehyde, chlorofluorocarbons, for industrial process wastewater. dichlorobenzene, ethyl acetate, methylnaphthalene, chlorotoluene, among others. Water Consumption Dust Water consumption in textile manufacturing has a significant environmental impact, in terms of freshwater needs, Dust emissions associated with textile manufacturing occur wastewater/sludge production, and energy used in heating. during natural fiber and synthetic staple processing and yarn Recommendations to reduce water consumption, especially manufacturing. Fiber (especially cotton) handling and storage where it may be a limited natural resource, are provided in the are sources of dust, particularly within work areas. The main General EHS Guidelines. Recommendations specific to this sources are bale breakers, automatic feeders, separators and sector include: openers, mechanical conveyors, pickers, and cards. The recommended prevention and control methods for these main • Reuse of dyebaths; sources of dust emissions include: • Adoption of continuous horizontal washers and vertical spray washers or vertical, double-laced washers; • Enclosure of dust producing equipment, and use of local • Adoption of countercurrent washing (e.g. reuse the least exhaust ventilation; contaminated water from the final wash for the next-to-last • Use of dust extraction and recycling systems to remove wash); dust from work areas; • Use of water flow–control devices to ensure that water only • Installation of fabric filters to prevent outdoor emissions. flows to a process when needed; The use of asbestos fibers as a source of natural fiber in the • Reuse of preparation and finishing water. manufacturing of staple is no longer considered good industry practice and must be avoided. APRIL 30, 2007 7 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP Air Pollutants from Fiber Manufacturing halogenated organic solvents cannot be avoided (e.g. for Regenerated fibers (viscose) and synthetic polymers (nylon and fabrics that are heavily loaded with silicone oils); acrylic fibers) production processes involve the potential release • Using appropriate control technologies (e.g. diversion of of chemicals (e.g. carbon disulfide, hydrogen sulfide, stack emissions through boilers; installation of scrubbers hexamethylene diamine, and nitric acid). Pollution prevention with activated carbon slurries; installation of activated and control measures include: carbon absorbers; or incineration of extracted vapors in a combustion system). • Air removed from the processes by the exhaust ventilation should be transported to a recovery system; Exhaust Gases • Use of emissions control techniques (e.g. absorption and Combustion sources for power generation and process heating chemical scrubbing). requirements are common in this industry sector. Guidance for the management of combustion products arising from sources VOCs and Oil Mists with a heat input capacity of up to 50 megawatt including air Emissions of VOCs are related to the use of organic solvents in emission standards, is provided in the General EHS activities such as printing processes, fabric cleaning, wool Guidelines . Guidance applicable to larger emissions sources scouring and heat treatments (e.g. thermofixation, drying, and are presented in the EHS Guidelines for Thermal Power. curing). Another source of emissions is the evaporation or Odors thermal degradation of chemicals used on the textile materials Odors may be generated in textile manufacturing, particularly (e.g. oil-based antifoaming agents, plasticizers, and finishing during dyeing and other finishing processes, and use of oils, agents). The main sources are often the stenter frames, which solvent vapors, formaldehyde, sulfur compounds, and ammonia. are used in drying. Other substances with significant air Techniques for the prevention or minimization of odor from emission potential are used in printing processes, including these sources include: ammonia, formaldehyde, methanols and other alcohols, esters, aliphatic hydrocarbons, and several monomers. • Substituting odor-intensive substances with less impacting compounds (e.g. sulfur containing dyestuffs and reducing Pollution prevention and control techniques include the agents with non-pre-reduced sulphide-free dyestuffs; following: sodium dithionite in dyeing after treatment with aliphatic • Installing and modifying equipment to reduce solvent use; short-chain sulfinic acid derivatives); • Adopting water-based methods for removing oil and grease • Installing and modifying equipment to reduce use of from fabric instead of using volatile solvents; odorous chemicals; • Substituting cleaning solvents with less toxic solvents, • Capturing and recovering the off-gases from the processes particularly chlorinated solvents; (e.g. installation of heat recovery systems); • Recovery of VOCs through vapor recovery units, and use • Routing of stack emissions through boilers to reduce odor of a fully closed-loop system, especially if cleaning with emissions. APRIL 30, 2007 8 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP Energy Consumption undertaken in accordance with guidance included in the Textile manufacturing may involve significant use of energy General EHS Guidelines. resources. Heat consumption is particularly significant in drying and curing operations and in activities involving wet treatments. 1.2 Occupational Health and Safety In addition to energy conservation measures discussed in the Occupational health and safety hazards during the operational General EHS Guidelines, the following techniques are specific phase of textile manufacturing projects primarily include the to this sector: following: • Adoption of low-bath-ratio dyeing (e.g. jet dyeing and • Chemical hazards package dyeing) to reduce energy consumption, which is • Physical hazards dependent on bath volume; • Heat • Use of pad batch (cold) dyeing for cotton, rayon, and • Noise blends to conserve energy and water (in addition to dyes • Ionizing and non-ionizing radiation and chemicals); • Consider efficient combination of operations, such as Chemical Hazards scouring and bleaching, to save energy and water; Respiratory & Dermal contact hazards • Use of continuous knit bleaching ranges instead of batch Dust: Exposure to fine particulates is mainly associated with preparation knitting equipment; natural fibers and yarn manufacturing processes described in • Use of heat recovery from continuous dyeing / bleaching Section 1.1. of this document. Cotton dust is generated during ranges to preheat incoming water and heat recovery the handling or processing of cotton and contains cotton fibers through reuse of cooling water and by heat exchange from and other potential chemical and microbiological contaminants hot effluents discharged by batch dyeing machines. (e.g. bacteria, fungi, pesticides, and herbicides). Exposure to cotton dust can generate respiratory hazards (e.g. byssinosis in Wastes cotton manufacturing, chronic bronchitis, asthma, and Wastes specific to the textile industry include trials, selvedge, emphysema). trimmings, cuttings of fabrics, and yarns; spent dyes, pigments, Prevention and control of occupational health and safety and printing pastes; and sludge from process wastewater hazards relevant to natural fiber dust include the following treatment containing mainly fibers and grease. Solid and liquid wastes generated in textile industries should be • Installation of dust extraction, recycling and ventilation effectively recycled or reused within the process or external (e.g. systems to remove dust from work areas, especially in waste fibers, cuttings, and trimmings can be recycled as a cotton mills; feedstock for other operations, including low-grade products, • Use of vacuum cleaning of surfaces instead of compressed non-wovens, insulation, and geotextiles). Management and air “sweeping” techniques; disposal of hazardous and non-hazardous wastes should be • Implementation of regular housekeeping procedures, especially in the “flocking” area; APRIL 30, 2007 9 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP • Use of mechanical methods to handle cotton and cotton • Use of personal protective equipment (PPE), such as waste; respirators, as necessary. • Use of personal protective equipment (PPE) for exposed workers, such as masks and respirators, as necessary. Chromium: is a major cause of allergic contact dermatitis among dyehouse workers and workers who perform dyeing Workplace exposure to asbestos dust during fiber production operations and handle dyestuffs containing chromium. represents a known risk of lung cancer (mesothelioma) and Prevention and control of this potential hazard include reduction injury to the bronchial tubes. The use of asbestos fiber is in the proportion of soluble chromium in dyestuffs and the use of prohibited.8 Appropriate dust extraction systems in facilities adequate PPE to prevent dermal contact, as described in the where inorganic natural fibers are processed should be General EHS Guidelines. implemented (e.g. filters using nano-whiskers). Explosion Volatile Organic Compounds (VOC) : Exposure to VOC Organic dusts, including cotton dust, are combustible and emissions is related to the use of solvents in textile printing present a potential explosion hazard. This hazard is most processes, fabric cleaning, and heat treatments (e.g. effectively controlled through the measures for prevention of thermofixation, drying, and curing). Worker exposure can cause dust accumulation as above. In addition, all possible sources of skin and respiratory impacts. Exposure to certain compounds ignition where organic dusts may form clouds or accumulate (e.g. carbon disulfide in rayon manufacturing) may have should be removed. VOC use, such as solvents, may form significant toxic effects, including nervous system and heart potentially explosive mixtures in air. Electrical equipment in diseases. these areas should be rated for ignition prevention. Prevention and control techniques to reduce VOC exposure Physical Hazards hazards include the following: Activities related to the maintenance operations of industry- • Use of hoods and enclosed equipment; specific equipment (e.g. cards, spinning machinery, looms, and • Use of well-ventilated rooms, with a slight positive stenters) may expose workers to physical impacts, particularly pressure, for process control operators, and as worker rest with reference to hot surfaces and moving equipment. stations; Prevention and control of these impacts include the • Use of shift and task rotation strategies for workers to implementation of general protection measures (e.g. machine minimize VOC exposure; guarding and lock-out-tag-out systems and procedures), as described in the General EHS Guidelines. • Installation of extraction and air recycling systems to remove VOCs from the work area with use of appropriate Heat abatement technologies (e.g. scrubbers employing The most significant risk of exposure to heat and high humidity activated carbon absorbers) or routing the extracted vapors occurs during wet processing and dry finishing operations and is to the combustion system; caused by the use of steam and hot fluids in these processes. 8Use of asbestos is not considered good industry practice and is prohibited according to the IFC Exclusion List. APRIL 30, 2007 10 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP Prevention and control recommendations are presented in the manufacturer should avoid using allergenic dyestuffs and General EHS Guidelines. dyestuffs that form carcinogenic compounds. Adequate testing for pH, pesticides, heavy metals, formaldehyde, chlorinated Noise phenols, chloro-organic carriers, and biologically active finishes The main sources of noise in textile plants are associated with should be conducted to assess textile characteristics according yarn processing (e.g. texturizing and twisting and doubling) and to the typical conditions of their use prior to entry into the woven fabric production. Noise management, including the use market.9 of personal hearing protection, is described in the General EHS Guidelines. Ionizing and Non-Ionizing Radiation X-ray stations are sometimes used for continuous monitoring of the foam thickness in continuous foam dyeing and for tank level control systems. Operators of this equipment should be protected through the use of ionizing radiation protection measures to limit exposure doses, as described in the General EHS Guidelines. 1.3 Community Health and Safety Community health and safety impacts during the construction and decommissioning of textile manufacturing plants are common to those of most industrial facilities, and are discussed in the General EHS Guidelines. Specific potential impacts during operations include odors that are produced by several sources in textile manufacturing. Odors are usually generated during dyeing and other finishing processes by oils, solvent vapors, formaldehyde, sulfur compounds, and ammonia. They should be adequately controlled and contained, as discussed in Section 1.1, to avoid becoming a nuisance for the community. An additional community health and safety issue concerns the use of chemicals and their potential risk to the health of consumers who purchase garments or home textiles produced by the textile industry. Specific consideration should be given to 9 Specific guidance can be found in the Oeko-Tex Standards (2006a, 2006b, ensuring that these products are safe for human use. The 2006c). APRIL 30, 2007 11 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP 2.0 Performance Indicators and Table 1. Air emission levels for textile industry d Monitoring Pollutants Units Guideline Value VOCs mg/Nm 3 2 / 20 / 50 / 75 / 100 / 150 a b 2.1 Environment Chlorine mg/Nm 3 5 Emissions and Effluent Guidelines Formaldehyde mg/Nm 3 20 Tables 1 and 2 present emission and effluent guidelines for this Ammonia mg/Nm 3 30 sector. Guideline values for process emissions and effluents in Particulates mg/Nm 3 50c this sector are indicative of good international industry practice H2S mg/Nm 3 5 as reflected in relevant standards of countries with recognized regulatory frameworks. These guidelines are achievable under CS2 mg/Nm 3 150 NOTES: normal operating conditions in appropriately designed and a Calculated as total carbon. b As the 30-minute mean for stack emission. Applicability of guideline values: operated facilities through the application of pollution prevention - 2 mg/Nm 3 for VOCs classified as carcinogenic or mutagenic with mass flow greater than or equal to 10 g/hour; and control techniques discussed in the preceding sections of - 20 mg/Nm 3 for discharges of halogenated VOCs with a mass flow equal or this document. These levels should be achieved, without greater than 100 g/hour; - 50 mg/Nm3 for waste gases from drying for large installations (solvent dilution, at least 95 percent of the time that the plant or unit is consumption >15 t/a); - 75 mg/Nm³ for coating application processes for large installations (solvent operating, to be calculated as a proportion of annual operating consumption >15 t/a); - 100mg/Nm³ for small installations (solvent consumption <15 t/a). hours. Deviation from these levels in consideration of specific, - If solvent is recovered from emissions and reused, the limit value is 150 mg/Nm³ local project conditions should be justified in the environmental c As the 30-minute mean for stack emissions. d Guideline values are applicable to installations with a solvent consumption > assessment. 5t/a. Effluent guidelines are applicable for direct discharges of treated effluents to surface waters for general use. Site-specific discharge levels may be established based on the availability and conditions in use of publicly operated sewage collection and treatment systems or, if discharged directly to surface waters, on the receiving water use classification as described in the General EHS Guidelines. Emissions guidelines are applicable to process emissions. Combustion source emissions guidelines associated with steam- and power-generation activities from sources with a heat input capacity equal to or lower than 50 MW are addressed in the General EHS Guidelines with larger power source emissions addressed in the EHS Guidelines for Thermal Power. Guidance on ambient considerations based on the total load of emissions is provided in the General EHS Guidelines . APRIL 30, 2007 12 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP Resource Use Table 2. Effluent levels for the textile industry a Tables 3 and 4 provide examples of industry-specific indicators Pollutants Units Guideline Value for resource and energy consumption and waste generation. pH -- 6 –9 These benchmark values are provided for comparative BOD mg/L 30 purposes only, and individual projects should target continual COD mg/L 160 improvement in these areas. AOX mg/L 1 TSS mg/L 50 Table 3. Resource and energy consumption a Oil and Grease mg/L 10 Electrical Thermal Water Energy Energy Consumption Pesticides mg/L 0.05-0.10 b Process (kWh/kg) (MJ/kg) (l / kg) Cadmium mg/L 0.02 Wool Scouring 0.3 3.5 2–6 Chromium (total) mg/L 0.5 Yarn Finishing – – 70–120 Chromium (hexavalent) mg/L 0.1 Yarn Dyeing 0.8–1.1 13–16 15–30 (dyeing) Cobalt mg/L 0.5 30–50 (rinsing) Loose Fiber 0.1– 0.4 4–14 4–15 (dyeing) Copper mg/L 0.5 Dyeing 4–20 (rinsing) Nickel mg/L 0.5 Knitted Fabric 1–6 10–60(2) 70–120 Zinc mg/L 2 Finishing Woven Fabric 0.5–1.5 30–70(3) 50–100 Phenol mg/L 0.5 Finishing Dyed Woven – – <200 Sulfide mg/L 1 Fabric Finishing a European Commission (2003b). The data of “industry benchmarks” originate Total Phosphorous mg/L 2 from only a limited number of installations. b The higher value is for mills also having spinning and coning sections. Ammonia mg/L 10 c The higher value is for mills also having spinning, twisting, and coning sections. Total Nitrogen mg/L 10 m-1 7 (436 nm, yellow) Color 5 (525 nm, red) 3 (620 nm, blue) Toxicity to Fish Eggs T.U. 96h 2 Temperature increase °C <3 Coliform bacteria MPN/100ml 400 a At the edge of a scientifically established mixing zone which takes into account ambient water quality, receiving water use, potential receptors and assimilative capacity b 0.05 mg/L for total pesticides (organophosphorous pesticides excluded); 0.10 mg/l for organophosphorous pesticides. APRIL 30, 2007 13 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP Table 4. Waste generation.a Environmental Monitoring Environmental monitoring programs for this sector should be Outputs per unit of product Unit Industry Benchmark implemented to address all activities that have been identified to Wastewater have potentially significant impacts on the environment, during l/kg 2–6 b Wool Scouring both normal operations and unsettled conditions. Environmental Wastewater monitoring activities should be based on direct or indirect Yarn Finishing l/kg 35–45 indicators of emissions, effluents, and resource use applicable Wool to the particular project. Wastewater Yarn Finishing l/kg 100–120 Cotton Monitoring frequency should be sufficient to provide Wastewater representative data for the parameter being monitored. Yarn Finishing l/kg 65–85 Synthetic Fiber Monitoring should be conducted by trained individuals following Wastewater monitoring and record-keeping procedures and using properly Knitted Fabric Finishing l/kg 60–70 Wool calibrated and maintained equipment. Monitoring data should be Wastewater analyzed and reviewed at regular intervals and compared with Knitted Fabric Finishing l/kg 60–135 the operating standards so that any necessary corrective Cotton actions can be taken. Additional guidance on applicable Wastewater Knitted Fabric Finishing l/kg 35–80 sampling and analytical methods for emissions and effluents is Synthetic Fiber provided in the General EHS Guidelines. Wastewater Woven Fabric Finishing l/kg 70–140 Wool 2.2 Occupational Health and Safety Wastewater Woven Fabric Finishing l/kg 50–70 Occupational Health and Safety Guidelines Cotton Wastewater Occupational health and safety performance should be Woven Fabric Finishing + l/kg 150––80 evaluated against internationally published exposure guidelines, Print Cotton of which examples include the Threshold Limit Value (TLV®) Wastewater occupational exposure guidelines and Biological Exposure Woven Fabrics Finishing l/kg 100-180 Synthetic Fiber Indices (BEIs®) published by American Conference of Sludge kg/m 3 treated Governmental Industrial Hygienists (ACGIH),10 the Pocket from Wastewater wastewater 1–5 c Treatment Guide to Chemical Hazards published by the United States a European Commission (2002b). National Institute for Occupational Health and Safety (NIOSH),11 b BAT is 2–4 l/kg of greasy wool for medium and large mills (15000 tons/year of greasy wool) and 6 l/kg for small mills. Permissible Exposure Limits (PELs) published by the c Volume of sludge produced after dewatering 1–5 kg/m3 of treated wastewater. Occupational Safety and Health Administration of the United 10 Available at: http://www.acgih.org/TLV/ and http://www.acgih.org/store/ 11 Available at: http://www.cdc.gov/niosh/npg/ APRIL 30, 2007 14 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP States (OSHA),12 Indicative Occupational Exposure Limit Values published by European Union member states,13 or other similar sources. Accident and Fatality Rates Projects should try to reduce the number of accidents among project workers (whether directly employed or subcontracted) to a rate of zero, especially accidents that could result in lost work time, different levels of disability, or even fatalities. Facility rates may be benchmarked against the performance of facilities in this sector in developed countries through consultation with published sources (e.g. US Bureau of Labor Statistics and UK Health and Safety Executive)14. Occupational Health and Safety Monitoring The working environment should be monitored for occupational hazards relevant to the specific project. Monitoring should be designed and implemented by accredited professionals as part of an occupational health and safety monitoring program. Facilities should also maintain a record of occupational accidents and diseases and of dangerous occurrences and accidents.15 Additional guidance on occupational health and safety monitoring programs is provided in the General EHS Guidelines. 12 Available at: http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDAR DS&p_id=9992 13 Available at: http://europe.osha.eu.int/good_practice/risks/ds/oel/ 14 Available at: http://www.bls.gov/iif/ and http://www.hse.gov.uk/statistics/index.htm 15 Accredited professionals may include certified industrial hygienists, registered occupational hygienists, certified safety professionals, or their equivalent. APRIL 30, 2007 15 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP 3.0 References and Additional Sources Denton, M. J., and P. N. Daniels. 2002. Textile Terms and Definitions. Organization for Economic Co-operation and Development (OECD). 2004. Cambridge: Woodhead Publishing Ltd. Emission Scenario Document on Textile Finishing Industry. OECD Series on Emission Scenario Documents, Number 7. Doc. ENV/JM/MONO(2004)12. Paris, Environment Australia. 1999. National Pollutant Inventory: Emission Estimation France. Technique Manual for Textile and Clothing Industry. Canberra, Australia. Oslo and Paris Conventions for the Prevention of Marine Pollution, Joint European Commission. 2002. Decision 2002/371/EC of 15 May 2002 Meeting. 1997. PARCOM Recommendation 97/1 Concerning Reference Values Establishing the Ecological Criteria for the Award of the Community Eco-label to for Effluent Discharges from Wet Processes in the Textile Processing Industry. Textile Products and Amending Decision 1999/178/EC. Brussels, Belgium. Brussels, Belgium European Commission. 2003a. Integrated Pollution Prevention and Control Republic of Italy. 1999. Decreto Legislativo 11 Maggio 1999. No. 152. (IPPC), Reference Document on Best Available Techniques for Common Waste Disposizioni sulla Tutela delle Acque dall’Inquinamento e Recepimento della Water and Waste Gas Treatment and Management Systems in the Chemical Direttiva 91/271/CEE Concernente il Trattamento delle Acque Reflue Urbane e Sector. Seville, Spain della Direttiva 91/676/CEE Relativa alla Protezione delle Acque dall’Inquinamento Provocato dai Nitrati Provenienti da Fonti Agricole. Gazzetta Ufficiale della Repubblica Italiana, No. 124. Rome, Italy. European Commission. 2003b. Integrated Pollution Prevention and Control (IPPC), Reference Document on Be st Available Techniques for the Textile Industry. Seville, Spain. Republic of Italy. 2006. Decreto Legislativo 3 Aprile 2006, No. 152. Norme in Materia Ambientale. Gazzetta Ufficiale della Repubblica Italiana, No. 96/L. Rome, Italy. European Union. 1999. Council Directive 1999/13/EC of 11 March 1999 on the Limitation of Emissions of Volatile Organic Compounds due to the Use of Organic Solvents in Certain Activities and Installations. Brussels, Belgium. State Government of Victoria, Environmental Protection Authority. 1998. Environmental Guidelines for the Textile Dyeing and Finishing Industry. Melbourne, Australia. European Union. 2002.Council Directive 2002/61/EC of 19 July 2002 Amending for the Nineteenth Time Council Directive 76/769/EEC Relating to Restriction on the Marketing and Use of Certain Dangerous Substances and Preparations U.K. Environmental Agency. Scottish Environmental Protection Agency. (Azocolourants). Brussels, Belgium. Environmental and Heritage Service. 2002. Guidance for the Textile Sector. Sector Guidance Note IPPC S6.05. London, U.K. German Federal Government. 2002. First General Administrative Regulation Pertaining to the Federal Emission Control Act (Technical Instructions on Air United Kingdom. Health and Safety Commission. 2005. Workplace Exposure Quality Control—TA Luft). Berlin, Germany. Limits. Table 1: List of Approved Workplace Exposure Limits. EH40/2005. London, U.K. German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety. 2004. Promulgation of the New Version of the Ordinance on U.S. Department of Health and Human Services (DHHS). National Institute for Requirements for the Discharge of Waste Water into Waters (Waste Water Occupational Safety and Health. 1988. Occupational Safety and Health Ordinance—AbwV) of 17 June 2004. Berlin, Germany. Guideline for Cotton Dust. Washington, DC: U.S. DHHS. Helsinki Commission. 2002. Reduction of Discharges and Emissions from U.S. Environmental Protection Agency. Office of Compliance. 1997. Sector Production of Textiles. Recommendation 23/12. Helsinki, Finland. Notebook Project. Profile of the Textile Industry. EPA/310-R-97-009. Washington, DC: U.S. EPA.. Japan International Center for Occupational Safety and Health. 2001–2002. Accident Frequency Rates and Severity Rates by Industry (2001–2002). Tokyo, U.S. Environmental Protection Agency (EPA). 2000. Emergency Planning and Japan. Community Right-To-Know Act. Section 313, Reporting Guidance for the Textile Processing Industry. EPA 745-B-00-008. Washington, DC: U.S. EPA. North Ireland Department of the Environment. 2004. Textile and Fabric Coating and Finishing. Process Guidance Note NIPG 6/8 (Version 2). Belfast, Northern U.S. Environmental Protection Agency. 40 CFR Part 410. Protection of Ireland, U.K. Environment—Textile Mills Point Source Category. Washington, DC: U.S. EPA. Oeko-Tex Association, International Association for Research and Testing in the Field of Textile Ecology. 2006a. Oeko-Tex Standard 100. Available at http://www.oeko-tex.com/en/main.html Oeko-Tex Association, International Association for Research and Testing in the Field of Textile Ecology. 2006b. Oeko-Tex Standard 200. Available at http://www.oeko-tex.com/en/main.html Oeko-Tex Association, International Association for Research and Testing in the Field of Textile Ecology. 2006c. Oeko-Tex Standard 1000. Available at http://www.oeko-tex.com/en/main.html APRIL 30, 2007 16 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP Annex A: General Description of Industry Activities The textile industry includes the production of yarn, fabric, and undertaken. Natural mineral fibers including basalt fibers (both finished goods. Textile manufacturers receive and prepare raw continuous filaments and staple fibers) and asbestos (a staple fibers; transform fibers into yarn, thread, or webbing; convert the fiber) are known. Manmade fibers include synthetic organic yarn into fabric; and dye, finish, and assemble these materials at materials from the petrochemical industry (e.g. polyamides, various stages of production. Raw materials used in textile polyesters, polyolefins, and polyacrylic fibers), and regenerated manufacturing include natural fibers (organic or inorganic), natural organic fibers, including regenerated cellulose (viscose chemical and manufactured fibers, chemicals, water and and cupro form), cellulose acetate, and triacetate manufactured energy. (See Table A-1).16 from wood fibers. Manmade fibers may be processed into filament yarn or staple-length fibers to facilitate spinning. Table A.1. Textile Fibers Manmade inorganic fibers include glass and carbon fibers, which are continuous filaments and staple fibers. The staple Categories / Sub- Categories Examples fibers of both of these materials are used in felts and composite. Cotton Vegetable Fibers Flax, Hemp The continuous filament of glass is processed by spinning, Organic Jute, Sisal, Broom twisting, and sizing. The continuous filaments of carbon are Natural Fibers Wools Animal Fibers produced by pyrolisis. Silk Basalt Inorganic Mineral Fibers Asbestos Yarn Manufacturing Regenerated cellulose Staple (including natural, regenerated natural, and manmade) Viscose Organic Regenerated Natural Fibers Cupro fibers are transformed into yarn through grouping and twisting Cellulose acetate operations. Other fibers are processed using spinning Cellulose triacetate Man-made Fibers Polyamide operations. Yarn manufacturing typically includes the following Polyester operations: Organic Synthetic Polymers Polyolefins Polyacrilic Glass • Vegetable fibers: ginning, fiber blend, carding, combing, Inorganic Fibers Carbon spinning (that is, ring and open end), and twisting • Animal fibers: scouring, fiber blend, carding, combing, spinning (ring), and twisting Fiber Manufacturing / Preparation • Mineral fibers: spinning, twisting, and sizing The textile industry uses two general categories of fibers, • Regenerated natural fibers: carding, combing, spinning namely natural and manmade . Natural fibers, known as staple (ring), and twisting fibers when harvested, include vegetable and animal fibers (e.g. • Manmade fibers: carding, combing, spinning (ring or open cotton, silk, and wool). Before these fibers can be spun into end), and twisting yarn, a series of preparation phases, including ginning, opening, blending, scouring, carding, combing, and drafting are Continuous filament yarn may be used directly or after the 16Specific terms and definition used in textile manufacturing can be found in following operations: Textile Terms and Definitions 11th Edition, 2002 APRIL 30, 2007 17 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP • Natural fibers (for example, silk): twisting during weaving. The primary sizing compounds include starch, • Regenerated natural fibers: spinning and twisting gelatin, oil, wax, and manufactured polymers (such as polyvinyl • Manmade fibers: spinning, twisting, and texturizing alcohol, polystyrene, polyacrylic acid, and polyacetates). • Inorganic fibers: spinning (glass) or pyrolisis (carbon), The beam-to-beam sizing method transfers a warp from a warp twisting, and sizing beam to a loom beam. The sized warp is dried by hot air or by Fabric Production Winding Winding involves transferring yarn from one type of package to contact with steam-heated cylinders during its transfer to the another to facilitate subsequent processing. Precision winders loom beam. are used primarily for filament yarn and produce packages with a diamond-patterned wind. Drum winders are used mainly for Fabric Manufacture spun yarns. The most important methods for fabric manufacture are weaving and knitting. Weaving is done using looms (any set of devices Warping permitting a warp to be tensioned and a shed to be formed with Warping involves winding a portion of the total number of ends the aid of heddles). There are many kinds of looms including of a warp in full width onto a back beam. shuttle, projectile, rapier, and fluid jet. The shuttle loom uses a weft insertion device that propels the filling yarn across (over Section Warping and under) the warp yarns. The projectile loom uses a projectile Section warping is a machine method of preparing a warp on a that conveys the weft through the shed and leaves a trail of yarn beam. The process involves winding a warp in sections on a behind it. The rapier-type loom conveys a weft yarn from a reel and beaming off the complete warp from the reel onto a stationary package through the shed. Rapier looms are simpler warp beam. and more versatile than dummy-shuttle looms, however their weaving speed is slower. The two types of fluid-jet looms are air Beaming jet and water jet. Beaming is an activity during warp-making in which ends, withdrawn from a warping creel, are wound onto a beam to a Knitting is a method of converting yarn into fabric by length that is a multiple of the loom warp length. Several similar intermeshing loops, which are formed with the help of needles. beams (known as a set of back beams) provide the total number Two weft-knitting technologies are used including flat bed (used of ends required in the woven warps. Beaming is usually for heavier gauge material) and circular. Warp-knitting implemented for bulk production of grey warp. Direct beaming is technologies include chain (e.g. lace, light tricot), raschel (e.g. a specific single-stage method. lace, velvet, technical fabrics), and crochet (e.g. technical fabrics). Sizing Sizing involves applying sizing compounds to warp yarn to bind Tufting is a process used to make carpets. Non-woven fabrics the surface fiber together and protect the yarn against abrasion are produced using mechanical-bonding, water-bonding, and air-bonding machines. Braiding is an interlacing technology in APRIL 30, 2007 18 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP which two sets of continuous fibers are interwoven sized with water-insoluble starches or mixtures of starch and symmetrically around an axis. other materials. Desizing is often conducted through the use of enzymes capable of breaking starches into water soluble Finishing Processes sugars. Sugars are then removed by washing before fabric Woven and knit fabrics are not normally processed into apparel scouring. or other finished goods until the undyed and unfinished fabrics, known as gray (woven) or greige (knit) fabrics, have passed Gassing or Singeing through several water-intensive wet-processing stages. These Gassing or singeing involves passing protruding fibers from yarn processes convert them into finished fabrics, enhancing their or fabric over a flame or heated copper plates to burn them off.. appearance, durability, and serviceability. Wet processing or finishing processes include the main processes of fabric Spinning preparation, namely dyeing, printing, and other specific Spinning involves creating yarn from raw fiber material. treatments. These phases treat fabrics with chemical and liquor Compact or condensed spinning is a modification of the ring- baths and often require several washing, rinsing, and drying spinning process, which allows lower fiber waste production, steps. greater exploitation of fiber tenacity, enhanced appearance, and lower hair content of spun yarn. Preparation Preparation (also known as pretreatment) of dyed, printed, or Mercerizing finished fabrics consists of a series of treatment and rinsing Mercerizing consists of the treatment of cellulosic textile fibers steps, which are critical for the results in subsequent textile (both yarn and fabric) with a concentrated solution of caustic finishing processes. Mills are used to remove natural impurities alkalis. The treatment allows fibers to swell and increases the or processing chemicals that may interfere with dyeing, printing, strength and dye affinity of the materials. An alternative process and finishing. Typical preparation treatments include desizing, uses liquid ammonia treatment produces some of the effects of scouring, and bleaching, as well as other processes (e.g. mercerization. gassing or singeing and mercerizing) designed to chemically or physically alter the fabric. Some pollutants generated during this Bleaching Bleaching is a process to improve the whiteness of textile phase may result from the removal of previously applied material, commonly using chlorine-based bleaches (sodium processing chemicals and agricultural residues. Wastewater hypochlorite and sodium chlorite) or hydrogen peroxide. may include metals, organics, and phosphorus contained in the Peracetic acid bleaching is sometimes used for synthetic fibers surfactants and detergents. that cannot be bleached using hydrogen peroxide (e.g. Desizing polyamide). Desizing is the preparation step used to remove size materials Dyeing applied before weaving. As manmade fibers are generally sized Dyeing is the application and fixing of a dye to a substrate. The with water-soluble sizes, removal is usually done by hot water textile industry uses several dyeing techniques (e.g. yarn wash or in the scouring process. Natural fibers are most often package dyeing, piece dyeing, spray dyeing, top [stock] and APRIL 30, 2007 19 Environmental, Health, and Safety Guidelines TEXTILE MANUFACTURING WORLD BANK GROUP hank [skein] dyeing) and machines (e.g. winch, jet, paddle, Coating and Laminating overflow) to dye the fabric through a liquor. Dyeing is conducted Coating involves the application of semiliquid material on one or in the textile manufacturing plant or by specialty dyehouses. both sides of a textile material. Drying and curing, as necessary, of the coating material forms a bond with the fabric. Techniques Textiles are dyed using a wide range of chemicals and include direct coating (e.g. spreading the coating with a knife); dyestuffs. Dyes are normally synthetic molecules and are sold roller coating (e.g. application through a roller to the moving as powders, granules, pastes, and liquid dispersions. Dyeing substrate fabric); and transfer coating (e.g. application to a can be performed using batch or continuous processes. In batch temporary substrate and the addition of an adhesive coating, the dyeing, a quantity of the textile is loaded into a dyeing machine tie coat, to allow transfer to the desired substrate). Flame and put in contact with the dye liquor. Auxiliary chemicals and lamination is widely used with thin, thermoplastic foam sheet bath conditions are used to accelerate the dyeing action. The (e.g. polyurethane) exposed to a wide flame burner located dye is then fixed using heat and / or chemicals, and a wash before the laminating rolls. removes unfixed dyes and chemicals from the textile fiber or fabric. The liquor ratio (the weight ratio between the total dry Wet processing produces the most significant amounts of material and the total liquor) of the equipment used is an emissions and waste in textile operations. Additionally, important parameter in discontinuous dyeing. This ratio ranges significant quantities of energy are needed for heating and from 3:1 (less water needed per unit weight of textile material) to cooling baths and for drying fabrics and yarn. Methods used more than 50:1 (typical of low-affinity dyes and less efficient or vary depending on end products and applications, site-specific more demanding dyeing processes). Dying winches and hank manufacturing practices, and fiber type. Natural fibers typically machines use higher ratios than jet drying, package dyeing, and require more processing steps than synthetic fibers. Processing pad batch techniques. Continuous dyeing processes feed the methods may differ based on the final properties desired, such textiles into a dye machine where dye application in a bath, dye as tensile strength, flexibility, uniformity, and luster. fixation with chemicals or heat, and washing are conducted at speeds between 50 and 250 meters of fabric per minute. Manufactured textiles are often shipped from textile mills to dyeing and finishing shops for wet processing, although large Printing textile manufacturing plants may have integrated wet processing Printing produces designs or motifs on the fabric by applying a into their operations. colorant or other reagent, usually in a paste or ink. Techniques include screen printing (in which a print paste is forced through Manufacturing of End Products a mesh, in contact with the substrate), sublimation printing (in Manufacturing of textile end products includes finished fabric which dyes that sublime readily are applied), and ink-jet printing. decoration, such as embroidery, garment assembly, home interiors, and other industrial uses of finished fabrics. Stentering Embroidery is the art of decorating fabric or other materials with Stentering straightens and dries products using hot air, resulting designs stitched in strands of thread or yarn using a needle. in the desired width for finished products. Embroidery may also incorporate other materials such as metal strips, pearls, and so on. Garment assembly may be a labor- intensive activity. APRIL 30, 2007 20