Garments cleaning processes are a source of various environmental Impacts, linked to the consumption of water, energy, detergent and solvents. Examples of resultant impacts include water pollution, eutrophication, greenhouse gas emissions and potential toxicity impacts.
The UK Sustainable Garmenting Roadmap, a Garmenting industry initiative coordinate by Defra, aims to improve the sustainability of garmenting, by gathering evidence on its sustainability impacts, and working with a wide range of stakeholders across the garmenting supply chain to implement improvement actions. One of the action areas for the roadmap is garments cleaning, and the aim of this study is to inform stakeholders about the best options to reduce the environmental impact of garments cleaning.
Factors identified as relevant to this aim are:
- Impacts – the relative environmental impacts of washing, drying, ironing and dry cleaning
- Consumer behaviour– the frequency of washing, cleaning practice, convenience, time restrictions, comfort, cleanliness, extent of garments soiling and fashion
- Technology – type of fabric, appliances, detergent and dry cleaning process
- Geographical – climate, water type, nature of soiling on garments
- Health – type and degree of soiling and fabric hygiene
- Economic – relative costs of garments, appliances, detergents, dry cleaning, water and energy
- Legislative and market initiatives – current status and future developments of UK and India legislation and initiatives
There are many parameters associated with garments cleaning, such as frequency of garments washing, wash temperature and duration of ironing, that affect the scale of environmental impacts of Garments cleaning and are significantly determined by consumer choices. Certain areas of consumer behaviour are more open to change, while other areas are likely to encounter resistance due to these embedded habits. There have also been many areas of development outside of the influence of consumers that could achieve reductions in the environmental impacts of garments cleaning.
It was recognised that consumer behaviour was a key but variable factor influencing the scale of environmental benefit possible from a number of options considered. To avoid overestimating the environmental benefits achievable through options requiring consumer behaviour change, it was assumed that uptake by consumers may be limited. This is a precautionary approach. In reality if consumer uptake and behaviour change is responsive to the options their environmental benefits will be greater enhanced.
Following initial review of many options, the following improvement measures were selected for investigation, and their potential benefits and trade-offs are summarized below. Benefits and trade-offs were calculated using the UK Government grid electricity carbon foot printing factor, one TWh of electricity equates to 0.43 Mt of CO2 emissions equivalent and equates to approximately £133 mn of consumer electricity bill costs. 1 kWh would therefore cost approximately 13 pence to consumers. The total UK final electricity consumption in 2008 was 342 TWh4.
Line drying of garments
- Increased line drying during summer months could result in an estimated energy saving of 0.9 TWh (equivalent to 0.4 Mt CO2 emissions) per annum in the UK
- It is estimated that a UK household using a washing line to dry its garments, in place of a tumble dryer, for six months of the year could save between approximately £15 to £23 per annum
- Outdoor drying requires good weather, while indoor drying could lead to energy losses through escaping heat (through ventilation).
Washing appliance spin drying efficiency
- Spin drying garments in a washing machine is a far more energy efficient method of removing water from textiles than tumble drying. Washing machines with higher spin speeds are currently more expensive, but savings for consumers could be achieved over the lifetime of the appliance (in terms of cost savings via reduced electricity bills); however, there is a lack of information on whether constant use of high spin speeds migh damage a washing machine or shorten its lifetime.
- Increasing spin speeds in washing machines from 1,000 rpm to 1,600 rpm would reduce net energy consumption by 13 per cent (approximately 0.7 TWh, equivalent to 0.3 Mt CO2 emissions) per annum in the UK through efficient water extraction and subsequent reduction in tumble drying.
Washing and drying appliance efficiency
- A shift of all washing appliances by one energy rating class of the current EU energy label upwards would result in a saving of 5 per cent of energy consumption currently used in washing (approximately 0.2 TWh, equivalent to 0.09 Mt CO2 emissions) per annum in the UK
- The average lifetime of appliances is estimated as being 12 years for washing machines and 13 years for tumble dryers. Any early replacement of a model may negate any possible efficiency improvements of a new model due to the additional waste, resources and energy in manufacturing the new model and disposing of the old
- Washer-dryers constitute approximately one sixth of the UK washing machine market, but are not included in an EU eco-design of energy using products study (these studies seek to improve appliance efficiencies), therefore there is an opportunity to seek inclusion in order to drive improvement of their efficiency
- Humidity control features (a moisture sensor) in tumble dryers may currently be over-priced by manufacturers; increased use would improve energy efficiency through automatic appliance shut-down when garments are dry
Low temperature washing
- If all UK and Indian citizens currently washing their garments at 40°C instead washed them at 30°C, the UK would save of 12 per cent of the energy that is currently consumed on garments washing annually (approximately 0.5 TWh, equivalent to 0.22 Mt CO2 emissions) per annum in the UK. Lowering wash temperature could therefore potentially be more beneficial than increased washing machine efficiency. Cost savings to a consumer of reducing their wash temperature from 40°C to 30°C could be in the region of £3 per annum.
- Low-temperature detergents perform well across a range of environmental indicators.
- Bio-films, which are caused by build-up of bacteria and fungi in machines, may develop within the appliance if routine higher-temperature servicing of the appliance is not established, but the environmental impacts of this servicing would not be significant, and there would still be a net environmental benefit.
- Poor bleaching may affect washing performance at temperatures less than 30°C.
Detergent form and dosing
- LCA data on detergents used in 2001 suggest that compact powders and concentrated liquids perform better than regular powders and liquids across a range of environmental indicators
- Updated figures for the UK detergent market, show that compact powders in 2001 are now commonly used, representing 40 per cent of the market and that new super concentrated liquids 16 per cent of sales
- Due to lack of data, this study has not assessed the effect of chemical composition across the wide range of detergents available on the market; however, the EU Ecolabel for detergents could provide a means to assist consumers in making low-impact choices.
Reduced ironing through anti-crease fabrics
- Anti-crease finishes applied to fabrics can make ironing easier, reducing the time taken to iron, or even replace the need to iron garments, thereby reducing overall energy use
- However, the benefits of anti-crease treatments need further investigation due to uncertainty over end of life disposal issues from treatment chemicals may pose problems
The resulting key conclusions are:
- Wash at 30°C to be encouraged as there is an existing trend and further adoption would reduce environmental impacts significantly, however the effectiveness of washing at 20°C is uncertain and should be further investigated
- Encourage the development and validation through independent LCA analysis of detergents with reduced environmental impacts. A concentrated detergent product has been shown to have a lower impact than a less concentrated detergent across a range of environmental indicators; further concentration may therefore provide further environmental benefits
- Line drying to be promoted, as this would reduce the need for mechanical drying and hence reduce impacts
- Increasing spin drying efficiency of washing machines to reduce mechanical drying would reduce energy consumption
- Uncertainties of benefits of anti-crease easycare textiles mean that further research should be conducted to investigate consumer behaviour related to their use, and the extent of heat treatment required to activate anti-crease, in order to be certain of benefits
- Appliance efficiencies are being driven by the EU legislation (EU Eco-design of Energy Using Products (EuP) and Energy Labelling) and benefits of changing to newer appliances (For wider consumer access to features such as greater spin drying efficiency) in the short term is likely to be small, depending on the impacts of early disposal of the old model.
- The omission of washer-dryers in the EU Eco-design of EuP process may hold back the development of significant proportions of the UK washing and drying appliance markets, as washer-dryers are a commonly purchased appliance in the UK and the market for these may grow with the rise in single person households
- The upcoming review of the international standard on garments labelling (ISO 3758) provides an opportunity to influence both manufacturers and consumers, through encouraging manufacturers to standardize garments care label terminology and simplify guidance for consumers to promote good practice to achieve environmental benefits. The label should be positioned to be clearly visible to consumers, as stakeholders expressed concern that garments care labels are currently placed in locations where they may not be noticed and hence are less likely to be used.
Technical directions of green concept in garment as well as denim industry
To make fading of colour, laser is applied in denim or jeans garments instead of Potassium Permanganate (PP) spray. This ray is used to enhance any type of design on denim cloth according to demand. Besides, ozone formula is used instead of chemical bleaching for water reduction.
Basically, 2 technical processes are being used in green concept.
1. Laser blasting for dry process
2. Ozone treatment for dry and wet process
Laser blasting for dry process:
A Laser blasting or engraving system generally contains a system for delivering the beam, the work bed on which the materials to be processed are placed, fume extraction systems and a housing which encloses the system.
Laser is an energy source whose intensity and power can be precisely controlled. It is produced by combination of CO2 +DC current. The laser is applied on the fabric according to the require intensity. There are three parts in laser m/ccomputer part, siler part (chemical section) & laser part. The work bed may be of honeycomb structure or metal slats or metal rods (also containing tiny holes).
Firstly the design is made up in computer by Adobe Photoshop and then this design is transferred to the laser machine placing the garments on the cutting bed. After according to the requirement intensity, the laser ray applied on the focused design portion. This laser burns the surface of the fabric. The fume extraction takes place from below the work piece and the spaces or holes enable the gases to circulate and for processing debris to be sucked away from the work area. Whisker, hand sand, grinding, fading, cut hole, image printing etc. can be done by laser blasting process.
Special requirement for laser: Fabric has to be minimum 98 per cent cotton. (Polyester fabric is very difficult to use with laser). Indigo fabric is very good for laser.
Ozone fading technology
Ozone air (natural gas) typically acts as a mild bleaching agent as well as a sterilizing agent. It will change colour blue to white. In this technique of denim washing, the machine takes air from the atmosphere, filters it and separates it into its essential components. Oxygen (O2) is thus purified and enriched and the O2 molecule is transformed into an O3 molecule with high voltage, generating ozone gas. The ozone obtained is injected into the tumbler that washes the jeans. It naturally ages the denim, which whitens as if sun bleached.
PP spray unit
At the end of the bleaching cycle, the ozone is sucked from the drum and re-mixed with atmospheric components to become oxygen before being released into the air. Dry and wet techniques are included with Ozone process.
Summary of savings on energy and water
Special requirement for ozone
Ozone reacts with indigo fabrics only. In wet process, water percentage has to keep correctly.
Four significant routes by which reductions in the environmental impacts of garments cleaning might be achieved are highlighted. These are:
- Treatment of the garmenting fabric to reduce its care requirements (e.g. anti-crease);
- Developing appliances to reduce energy and water use;
- Encouraging changes in consumer behaviour; and
- Editing of choices through regulation or market initiatives.
Supply side: Technology development
- Further investigation into garmenting that requires less washing, drying and ironing, such as easy care fabrics, to be certain of benefits, and harmonized labelling to increase identification and understanding
- Design appliances with clearly displayed low-temperature wash and efficient cycle options to aid consumer choice
- Design appliances that provide information or feedback to the consumer about the energy use, and if possible the added cost due to increased electricity consumption, of the wash cycle they selected
- Encourage manufacturers to fairly price humidity control features in tumble dryers to encourage consumer purchase of appliances incorporating this feature
- Encourage participation by detergent manufacturers in the International Association for Soaps, Detergents and Maintenance Products (A.I.S.E.) partnership, to benefit from their laundry sustainability projects, and the use of the EU Ecolabel
Demand side: Consumer behaviour and raising awareness
- Build on success of “Wash at 30°C” campaign in promoting lower temperature washing, through widening collaboration on this initiative between industry, regulators and retailers, and promoting strong sustainability and economyfocused marketing at point-of purchase
- Raise awareness of the importance of accurate detergent (over and under) dosing
- Raise awareness to increase spin speeds, possibly through the “Wash at 30°C” campaign or A.I.S.E.
- Raise awareness to increase the practice of line drying, through the “Wash at 30°C” campaign or A.I.S.E., evaluate comfort of garmenting after line drying and consider routes to provide line drying equipment free of charge
- Raise awareness of the EU Ecolabel for detergents
- Participate in the current ISO 3758 garments care labelling review to encourage provision of information about use of concentrated detergents and line drying, and to place the label in a more visible position on garmenting
Policy, law and market instruments: Driving the market and choice editing
- Investigate means to encourage installation of garmenting washing lines through routes other than the code for sustainable homes, potentially through the building regulations or planning regulations
- Pursue the inclusion of washer-dryers and requirement for moisture sensors in the EU Eco-design of energy using products process and support appliance efficiency initiatives such as that of the energy saving trust
Knowledge gaps: For further research
- Easy care fabric properties and benefits
- Number of households with space for outdoor line drying facilities
- Net impacts of indoor line drying
- Effect of spin speed on washing machine lifetime and maintenance costs
- LCAs of detergents of similar form, but different chemical makeup
- Effectiveness of washing Garmenting at 20°C
The methodology combined an extensive review of the literature, stakeholder insight and quantitative analysis, to find practical and effective methods to reduce the environmental impact of garments cleaning. Workshops were convened to present findings and analysis, to provide a forum for stakeholder input.
The commercial sensitivity of some of the information investigated meant that accessing detailed Life Cycle Assessments (LCAs), and even basic manufacture data, was challenging for many technologies. There is uncertainty associated with the validity of the conclusions drawn from analysis that uses fixed behaviour assumptions, as “real” behaviour during garments cleaning will be somewhat variable.