Wikiversity

Design for the Environment/All Purpose Residential Cleaning

< Design for the Environment

The first commercially available detergent was Nekal sold in Germany in 1917, to relieve Germany of soap shortages from WWI[1]. Emergence of detergent has not only made home cleaning much easier, but also enhanced the cleaning effectiveness. Over the past century, detergent have evolved drastically due to its threat to human health as well as environmental impact. For instance, many detergent contained phosphate in the 1960’s, which contributed to the eutrophication of lakes and other water bodies, causing enhanced growth of choking aquatic vegetation that disrupted the normal function of the [w:Ecosystem|ecosystem] [2]. Very few modern detergent still contain phosphate. From continuous improvements for almost a century, today’s detergent seek not only cleaning effectiveness, but also reduction in its environmental impact and effect on human health.

Alternatives

Three alternatives that chose to analyze and compare

1)Baseline: Lysol All Purpose Cleaner[3]

  • 1200mL
  • $2.89
  • packaged in a pourable bottle
  • comes in multiple fragrances

2)Alternative One: Next GENERATION TM All Purpose Cleaner[4]

  • 500mL
  • $6.49
  • stored in a trigger spray bottle

3)Alternative Two: Ecogent All Purpose Cleaner[5]

  • 3780mL
  • $41.5
  • stored in pourable bottle
  • no scent

A thorough life cycle analysis will be conducted using an Eonomic Input-Output Life Cycle Analysis(EIOLCA), a Life Cycle Assessment(SLCA) and a cost analysis, to analyze and compare the environmental and societal impacts, as well as economic assessments of our three alternatives.

The EIOLCA identifies direct and indirect costs within different sectors, and then converts the economic costs to potential environmental impacts. It has three general types of analyzing models—custom model, hybrid model, and traditional model. The traditional models are the basis of the EIOLCA, given by the website. The custom model is a traditional model with the prices of sectors changed, while the hybrid model is the combination of traditional models. Four major environmental factors, namely Energy use, Greenhouse Gases, toxic release and conventional air pollutants will be analyzed and compared.

Streamlined Life Cycle Assessment (SLCA) is a semi-quantitative method to evaluate a product’s entire life cycle impacts to the environment and society. The goal is to identify environmental burdens associated with a product’s entire life cycle. A 5X5 matrix is used in this method, and each cell holds a score from 0 to 4 (poor to outstanding), with a total score of 100. In addition, each column indicates different product life stage, and each row indicates a single environment factor. SLCA is a fast way to compare a product’s influence to the environment, and gives a comprehensive result for comparing products’ impact to the environment separated by life stages.

A cost analysis is reported for each alternative, which will include direct and indirect costs. Cause minimizing the environmental impact may be the objective for much modern merchandise, yet, good economic performance has always been the absolute foundation for any successful product. Thus there must be a balance between environmental concern and profitability in order for any product to be successful.

Project Information

edit

MIE315 section 01, Team A13

  • Lucy Deng [lucy1111]
  • John Liao [johnl123d]
  • Thomas Cao [Tylc]
  • Jason Hung [Hungjaso]

Highlights and Recommendations

edit
 

Upon examining the Economic Input-Output Life Cycle Analysis(EIOLCA). Lysol is the best alternative in terms of its economic input-output ratio. The other two alternatives are eliminated mainly due to the surfactant ingredient of the next GENERATION cleaner which contributs a major impact to the environment, and the exceptionally high price of the ECOgent cleaner.

According to the Streamlined Life Cycle Anassessment(SLCA) scores, the ECOgent cleaner is the best, followed by the next GENERATION cleaner, and then the Lysol cleaner. This is due to the fact that ingredients in both Next Generation and Eco-gent cleaners are mostly natural, thus the extraction processes and mixing of the chemicals produces less Greenhouse Gases(GHG), while the ingredients in the Lysol cleaner requires much more complex extraction processes(i.e. the dry mill process for producing ethanol). This is because the Lysol cleaner contains a variety of chemicals such as ethanol, which will not naturally degrade when flushed down the drain, and requires water treatment. Finally, we conclude that the ECOgent cleaner is the best alternative in terms of environmental impacts, since ECOgent cleaner is a novelty product aiming to have the most naturally degradable ingredients.

From the Cost Analysis, it is evident that the Lysol cleaner is the best alternative. With a price ratio of almost 2:1 compared to the Lysol cleaner, it will be hard for the Eco-gent cleaner to overcome the price hurdle even though it has the least environmental impact.In conclusion, the Lysol cleaner is the best alternative in terms of economic performance.

Based on the SLCA, EIOLCA, and the cost analysis, we conclude that the Lysol cleaner is the most practical alternative for the present. Even though the Lysol cleaner received the lowest score of 58/100 in the SLCA, one must realize that SLCA's are strictly in accordance with the environmental impacts, and does not fully represent the viability of a product. The Lysol All Purpose Cleaner had the least energy use, GHG release, toxic release, as well as conventional air pollutants out of the three cleaners. The cost analysis further strengthens Lysol as the most practical cleaner, since the price of a Lysol cleaner is almost half as cheap as the second leading cleaner (ECOgent cleaner).

Nevertheless, as technology advances, along with our society's will of becoming a more environmentally friendly community, soon environmentally friendly cleaners may soon become practical.

Functional Analysis

edit

Baseline: Lysol TM All Purpose Cleaner

edit

LysolTM All Purpose Cleaner is a cleaning product that disinfects and cleans all types of surfaces. It not only disinfects and kills germs on hard non-porous surfaces, but also effectively cuts grease and grime. Furthermore, it also removes tough soap scum. On top of the cleaning the different surfaces, Lysol All Purpose Cleaners also deodorizes the surfaces.

Alternative 1: next GENERATION TM All Purpose Cleaner

edit

The next GENERATIONTM All Purpose Cleaner comes to existence as people become more aware about the environment and start to strive for a greener product than the traditional cleaner. It is as versatile as the traditional all purpose cleaner which is able to clean from the kitchen bench tops to the bathroom sinks. It has nearly the same performance as the traditional one, but contains less harmful chemicals.

Alternative 2 : Ecogent All Purpose Cleaner

edit

The ECOgent all purpose cleaner is a flexible cleaner. Not only is it environmentally friendly, but it also covers a very board range of uses that other cleaners don’t. ECOgent cleaner can be used in all daily household applications. In addition, its 100% natural formula allows it to not irritate skin; therefore it is especially user friendly to customers with sensitive skin[6] . The ECOgent cleaner is non-aquatic toxic, more importantly; it has a low dermal toxicity LD 50 of 2000 mg/kg and a oral toxicity LD 50 of 12526 mg/kg[7]. Therefore it is also safe for when small children and pets are involved.

Economic Input-Output Life Cycle Analysis

edit

General Assumptions

  • All prices are converted to 1997 US$ by using the US department of commerce CPI calculator.
  • The operating costs are minimized (treated close to zero) due to short lifespan of cleaner and therefore are insignificant compare to the other sectors
  • Since most of the ingredients of general cleaners are confidential, the composition of the ingredients is largely based on assumptions based on reports and various resources
  • All products are assumed to come in 500mL / unit


Baseline : Lysol TM All Purpose Cleaner

edit

The EIOLCA is conducted using the traditional model with “soap and other detergents manufacturing” sector to represent the Lysol All Purpose Cleaner. The following chart and graphs show the different types environmental impacts during the five life stages for making 1 million units of Lysol All Purpose Cleaner (estimated price of $1 each).


Energy Use

 

The above figure shows the energy consumption of each life stage of the Lysol cleaner. As expected, the pre-manufacturing and manufacturing stages are most energy consuming, due to the manufacturing and chemical mixing processes that require great amounts of energy.


Greenhouse Gases

 

The above figure shows the greenhouse gas emissions from the life cycle of a Lysol cleaner. The life stages are reversed to better show the releases of each stage. Pre-manufacturing and manufacturing are the two dominant stages in terms of Global Warming Potential (GWP) and CO2 releases. This is mainly due to the various manufacturing and chemical extraction processes that cause extensiveGreenhouse gases(GHG) release.


Toxic Releases

 

The most toxics are released during the pre-manufacturing stage. This is mainly due to the chemical extraction processes that prepare the raw materials for the production of the cleaning solution. Manufacturing and Disposal stages also have considerable amount of toxic releases. For the manufacturing stage, the processes are similar to the pre-manufacturing stage, but with less chemical extraction processes and more manufacturing processes. For the disposal stage, recycling the packaging material of the Lysol cleaner (High Density Polyethylene(HDPE)) requires a complicated process which generates a considerable amount of toxic release.

Alternative 1 : next GENERATION TM All Purpose Cleaner

edit

Since Next GENERATIONTM All Purpose Cleaner has similar performance as the traditional cleaner; therefore, a custom model is employed and 1,000,000 units are expected to be produced annually same as the Lysol cleaners.


Energy Use


Most energy is used during the Pre-production/Manufacturing phase, representing nearly 100% of the total energy usage. This is due to the fact that manufacturing of the chemicals and the extraction of the raw materials consume large amount of energy.


Greenhouse Gases


As shown in the figure, the Pre-production/Manufacturing stage accounts for 99% of the total GWP. Within that section, the production of surfactants cause the most GWP--8680 MTCO2E, while the transportation and the disposal stages together contribute to only 1% of the total GWP.


Toxic Release


Pre-production/Manufacturing phase again has the largest amount of toxic release. Within the sector, production of surfactants release about 7910kg of toxic substances, 74% of the total toxic release. The reason for this large amount is due to the fact that surfactants have a large part in the chemical compositions (about 8%) and its production produces a lot of toxic substances to land, water and air. Since most of the ingredients are biodegradable, the contribution to toxic release from the disposal phase is insignificant.


Conventional Air Pollutants


As shown in the figure,the Pre-production/Manufacturing phases had the largest air pollutants and CO emissions. The production of surfactants contributes the most in the sector and the least contributor is the production of the HDPE containers. The disposal stage causes the least amount of air pollutants emission due to the fact that most of the ingredients in the cleaner are biodegradable.

Alternative 2 : Ecogent All Purpose Cleaner

edit

Since ECOgent all-purpose cleaner contains no detergent and surfactant, its cleaning ability is expected to decrease. Therefore, ECOgent products uses a custom model producing 2,000,000 units each year.

Energy Use

 

According to the graph, most of the energy is comsumed during the pre-manufacturing stage. Energy used in the extraction of the ingredients is intensive relative to the rest of the life stage operations. It contributes to almost 88% of the total energy consumption.

Green House Gases

 

According to the graph above, a significant amount of energy is used in the premanufacturing phase, causing high CO2 release, which reaches as high as 2000 MTCO2E annually and contributes to 80% of the total green house gas production. Whereas little CH4, N2O, CFCs are produced as expected, because natural organic ingredients are being extracted which are mostly natural hydrocarbons.


Toxic release

 

Insignificant amount of toxic components are released during the use and disposal phases of the product, while most toxic release happens during premanufacturing stage as expected. This is due to the intensive use of energy during extraction of chemicals.


Air pollution

 

Premanufacturing again dominates the total Air pollutant release. Releases of air pollutant during the premanufacturing stage are mostly due to the operations in the factory, instead of the extraction of ingredients.

Streamlined LCA

edit

Baseline : Lysol TM All Purpose Cleaner

edit
Life Stages Material Choice Energy use Solid Residues Liquid Residues Gaseous residues Total
Pre-Manufacture 1 1 2 2 2 8/20
Product Manufacture 1 2 2 2 2 9/20
Product distribution 3 2 3 3 3 14/20
Product use 3 4 3 3 3 16/20
After-use and disposal 2 3 2 2 2 11/20
Total 10/20 12/20 12/20 12/20 12/20 58/100

Lysol All Purpose Cleaner uses many different chemicals, which are obtained through various industrial processes, such as the dry mill process for obtaining ethanol[8], and electrolysis of brine for obtaining chlorine. These processes require an excessive amount of energy input. The (High Density Polyethylene(HDPE)) Lysol uses for packaging is mostly recycled, however, HDPE production is energy intensive, using approximately 1kWh of energy for every one million USD worth of HDPE manufactured[9]. Therefore the majority of the environmental impact comes from the consumption of energy. Lysol has an extremely poor rating on energy consumption divided by net revenue, suggesting low energy efficiency. According to study, 86% of primary energy sources are fossil fuels, and the burning fossil fuels releases huge amounts of carbon dioxides, and other harmful gases into the air[10]. Low energy efficiency will translate to a lot more energy consumed for the same amount of cleaning solution, thus generating a lot more GHG and other pollutants compared to other all purpose cleaners (i.e. w:Sulphur_dioxide sulphur dioxide and nitrogen oxides)[11]. In terms of recycling, a lot of solid waste and a considerable amount of energy is used to to transport the bottles to the recycling sites.

Alternative 1 : next GENERATION TM All Purpose Cleaner

edit
Life Stages Material Choice Energy use Solid Residues Liquid Residues Gaseous residues Total
Pre-Manufacture 3 2 3 1 2 11/20
Product Manufacture 3 2 4 2 2 13/20
Product distribution 4 3 4 3 3 17/20
Product use 3 4 4 2 1 14/20
After-use and disposal 3 3 4 2 3 15/20
Total 16/20 14/20 19/20 10/20 11/20 70/100


First of all, the containers for this product are made of HDPE which are recyclable. Large amount of energy is required for the extraction of crude oil and natural gas. The process of turning them into plastic resins and surfactants are also energy intensive. Glycerin and alcohol are produced during the production of surfactants and liquid residues like water are generated in the production of HDPE resins. [12]Manufacturing of the HDPE containers requires extrusion, injection molding and blow molding[13]. All of these processes are energy intensive and produces liquid and gaseous residues. However, not a significant amount of solid wastes are generated since HDPE resins are recyclable. Truck transportation is required to carry the freights and therefore causing gaseous and liquid residues. Energy is also required for the transportation (for example, burning gasoline). The next GENERATION TM All Purpose Cleaner has similar performance as the traditional cleaner[14]. As a result, the amount of cleaner (consumables) used by an average household is minimized. Liquid and gaseous residues are produced during usage of the cleaner. Some chemicals evaporate into the air after the cleaner solution is sprayed on top of the house appliances. Energy is required for the recycling process and the sewage treatment. Some gaseous residues are produced after the solution evaporates. Large amount of liquid residues are generated as consumers pour the solution down the drain.

Alternative 2 : Ecogent All Purpose Cleaner

edit
Life Stages Material Choice Energy use Solid Residues Liquid Residues Gaseous residues Total
Pre-Manufacture 3 3 4 4 2 16/20
Product Manufacture 4 3 3 3 3 16/20
Product distribution 3 3 3 3 3 15/20
Product use 3 4 4 3 3 17/20
After-use and disposal 4 2 2 4 3 15/20
Total 17/20 15/20 16/20 17/20 14/20 79/100

The ECOgent all purpose surface cleaner is produced from 100% natural substances, meaning that they are also biodegradable after use. Ingredients such as, lactic acid and Xanthan gum are obtained from plants extracts and fermentation[15]. Furthermore, the extraction agents used in the process are natural substances that are approved for the production of natural cosmetics such as carbon dioxide (CO2), alcohol of plants origin, fats and oil from plants origin etc[16]. Other ingredients used in the production of the ECOgent all-purpose surface cleaner are the Polyglycoside wetting agents such as Disodium Cocopolyglucose Citrate, C10-C16 Alkyl polyglycoside and Alkyl Polysaccharide. These ingredients are complex compounds made by the chemical synthesis of glucose and fatty alcohol which are also natural substances [17]. Another important ingredient we should consider is high density polyethylene (HDPE). Combustion of crude oil is required for the preparation of HDPE, to produce 1 kg of HDPE, approximately 1¾ kg of oil is required ( raw material and energy used )[18].


Detergent surfactants such as [[w:Benzene|benzene] and benzene derived active compounds are the greatest contributor to solid residue. During use, these surfactants leave disinfectant residues on the environmental surfaces which contribute to development of bacterial resistance to biocides and antibiotics[19]. This implies that the disinfectant becomes less effective in cleaning harmful bacteria and pathogens which eventually leads to worse indoor air quality and affect people’s health. Since the ECOgent all-purpose clean promotes detergent free cleaning, it contains no surfactants which leaves no solid residues on environment surfaces.


Furthermore, water makes up 85% of the product[20]. This implies that less concentration of material is used and minimal diversity of material is used. This product is readily biodegradable in both anaerobic and aerobic environment, make it easy to remove and recycle. In addition to the liquid contain itself, after used the HDPE container will also have to be disposed of, and HDPE is also commonly recycled. Since, the product biodegrade readily under anaerobic environment, it participates very little in the sewage treatment process. The recycling of HDPE is a moderate energy intensive process.[21]. HDPE is International Organization for Standardization(ISO) rated as number 2 recycling plastic[21]. However Solid residues are produced during the recycling process of HDPE. In the screening and sorting phase, dirt, stones and rocks, metals, or other physical contaminants that present in the plastics are removed which results in solid residues. In addition, during granulating phase, large pieces of metal are also being removed, adding to solid residues[21].Since the ECOgent product rarely involved in sewage treatment process, liquid residue that is produced during the process will not be accounted for.

In terms of gaseous residue, the HDPE recycling process requires the heating and melting of plastics which requires the burning of fuel. The heating value for recycling 1 kg of HDPE is equivalent to ¾ kg of oil[21]It is less than oil but still significant. This process results in the production of water and carbon dioxide.

Cost Analysis

edit

Assumptions

  • The operating cost is assumed to be insignificant compare to the other cost and therefore is neglected.
  • All values used are in 2009 US dollar equivalent
  • no sensitivity analysis will be conducted, nor will the time value of money be taken into account


Baseline : Lysol TM All Purpose Cleaner

edit

Injection Molding machines: $200,000/each *2=$400,000[22] Assembly Cost (robotic arms): $40,000/each*5=$200,000[23] Labor Cost (Annually): $12/person/hr*1920hrs*50=$1,152,000 All ingredients in the cleaner are assumed to be outsourced. And the cost analysis is based on the production of 1 million units (1 year).

Direct Cost

edit

 

From the chart above, labor clearly uses the most money, while disposal cost amount to around two percent of the total cost.

Indirect Cost

edit

Through the life cycle of the Lysol cleaner, many processes including chemical extraction, transportation, etc causes environmental damage by greenhouse gas, tox release, as well as conventional air pollutants release. These releases are converted to Global Warming Potential (GWP) in units of mtCO2E. The cost of which can be estimated from the Chicago Climate Exchange[24]. CO2 emission cost is about $4/mt From EIOLCA, the total GWP in terms of mtCO2 is 635.79 Therefore, Indirect cost=$4/mt*635.79=$2,543

By examining the direct and indirect costs, we can conclude that the majority of the cost comes from the labor cost and raw material purchase. Disposal phase of the life cycle uses less than 2 percent of the total economic input.

Alternative 1 : next GENERATION TM All Purpose Cleaner

edit

The cost analysis is similar to the analysis conducted in EIOLCA Injection Molding machines[25]: $200,000/each *2=$400,000 Assembly Cost (robotic arms)[26]$200,000 Labor Cost (Annually): $1,152,000 All ingredients in the cleaner are assumed to be outsourced. And the cost analysis is based on the production of 1 million units (1 year).

Direct Cost

edit

As can be seen from the calculations, the majority of the costs fall under Capital Cost. This includes all the fixed costs from equipments, transportation costs and all the costs related to the outsourcing materials. Since most of the ingredients in the next GENERATION TM All Purpose Cleaner are biodegradable, the disposal cost is minor(less than 1% of the total cost).

Indirect Cost

edit

The product causes environmental costs due to the emission of Greenhouse. This can be estimated from the Chicago Climate Exchange[27].

CO2 emission cost is about $4/mt

From EIOLCA, the total GWP in terms of mtCO2 is 10,280

Therefore, Indirect cost = $41,120

Alternative 2 : Ecogent All Purpose Cleaner

edit

Direct cost

edit

Assume each bottle of ECOgent all purpose cleaner contains 500mL of liquid. The table below shows a listing of direct cost from premanufacturing and disposal of the product.

 

Indirect Cost

edit

“It is safe to use and store ECOgent around children or pets without concern for the harmful effects usually associated with cleaning products”[28] For the fact that ECOgent all purpose cleaner has a toxicity very close to water. Medical cost related to accidental ingestion of surfactant, especially by young children has been greatly reduced. In addition, common surfactants leave solid residues on environmental surfaces, which cause the increase in resistant of pathogen to disinfectant; this also contributes to health issues. This cost is difficult to estimate, however the fact that ECOgent leaves no solid residue has greatly reduce the medical cost associated with the problem

References

edit
  1. ↑ “Analytical Chemists job description”. [Online document].[ Accessed: March 2009] Available at HTTP http://www.123oye.com/job-descriptions/a/analytical-chemist.htm
  2. ↑ “Analytical Chemists job description”. [Online document].[ Accessed: March 2009] Available at HTTP http://www.123oye.com/job-descriptions/a/analytical-chemist.htm
  3. ↑ “LYSOL® All Purpose Cleaner – Pour”[Online document]. LYSOL® 2009 [Accessed: March 2009]. Available at http://www.lysol.com/products/all-purpose-cleaners/all-purpose-pour/
  4. ↑ ”Next generation”[Online document]. Next generation 2009 [Accessed: March 2009]. Available at HTTP http://www.nextgeneration.co.nz/
  5. ↑ “Price search results for Ecogent General Purpose Cleaner” [Online document] EROL shopping 2008 [Accessed: March 2009]. Available at HTTP http://shopping.erol.co.uk/product/Ecogent-General-Purpose-Cleaner-3.78L.html
  6. ↑ “ECOgent uses”, [Online document]. Cogent Environmental solution [Accessed: March 2009]. Available at HTTP http://www.ecogent.ca/products/eco_uses.htm
  7. ↑ “ECOgent Properties”, [Online document]. Cogent Environmental solution [Accessed: March 2009]. Available at HTTP http://www.ecogent.ca/products/eco_properties.htm
  8. ↑ “Health and safety rating” [Online document]. [Accessed: March 2009] Available at HTTP http://www.goodguide.com/products/171502-lysol-all-purpose-cleaner-disinfectant-pine/details#rating-6537480
  9. ↑ “EIO-LCA”[Online docuemnet]. [Accessed: March 2009] Avaliable at HTTP www.eiolca.net
  10. ↑ Ball, Max W.; Douglas Ball, Daniel S. Turner (1965). “This Fascinating Oil Business.” Indianapolis: Bobbs-Merrill. ISBN 0-672-50829-X.
  11. ↑ “Pollution from Fossil Fuel-Fired Electric Power Plants” [Online document] [Accessed: March 2009]. Available at HTTP (http://leahy.senate.gov/issues/environment/ca_stats.html)
  12. ↑ 16Shell Chemicals, “Sustainability of Alcohol-Derived Surfactants”, [Online document], [Accessed: March 2009], Available at: http://www-static.shell.com/static/chemicals/downloads/products_services/endler_cesio_2008_poster.pdf
  13. ↑ American Chemistry, “life cycle of a plastic product”, [Online document], [Accessed: March 2009], Available at: http://www.americanchemistry.com/s_plastics/doc.asp?CID=1571&DID=5972
  14. ↑ “next GENERATIONTM ,”[ Online document], [Accessed: March 2009], Available at: http://www.nextgeneration.co.nz/index.html
  15. ↑ “What is Xanthan gum?” [Online document]. wiseGEEK [Accessed: March 2009]. Available at HTTP http://www.wisegeek.com/what-is-xanthan-gum.htm
  16. ↑ “NaTrue Label: requirements to be met by natural and organic cosmetics” [Online document]. NaTrue – lable2008 [Accessed: March 2009]. Available at HTTP http://www.natrue-label.com/fileadmin/docs/pdf/NaTrue-Label_Requirements_V1-3_26022009.pdf
  17. ↑ ” Antimicrobial quaternary surfactants based upon alkyl polyglycoside” [Online document]. FreshPatents [Accessed: March 2009] Available at HTTP http://www.freshpatents.com/Antimicrobial-quaternary-surfactants-based-upon-alkyl-polyglycoside-dt20060119ptan20060014703.php
  18. ↑ ” US Patent 5888482 - Emulsifying composition based on alkylpolyglycosides and its uses” [Online Document]. Patentstorm US [Accessed: March 2009]. Available at HTTP http://www.patentstorm.us/patents/5888482/description.html
  19. ↑ “ECOgent Properties”, [Online document]. Cogent Environmental solution [Accessed: March 2009]. Available at HTTP http://www.ecogent.ca/products/eco_properties.htm
  20. ↑ “Full ingredients disclosure” [online documents] Chemspec, Inc., [ 1 March 2009]. Available at HTTP http://www.ecogent.ca/products/ingredient%20disclosure%201.pdf
  21. ↑ 21.0 21.1 21.2 21.3 ” Best Practice Guide for HDPE Recycling” [Online document] Clean Washington center [Accessed: March 2009]. Available at HTTP http://www.cwc.org/hdpe/hdpe1.htm
  22. ↑ K.D. Capital “Machines in the Plastic Injection Molding Category”, [Online document], [Accessed: March 2009], Available at: http://www.kdcapital.com/Machines.cfm/ID/4009
  23. ↑ Trend Robotics, [Online document], [Accessed: March 2009], Available at: http://www.trendrobotics.com/products.php?list=C1
  24. ↑ Chicago Climate Exchange, [Online document], [Accessed: March 2009], Available at: http://www.chicagoclimatex.com/market/data/summary.jsf
  25. ↑ K.D. Capital “Machines in the Plastic Injection Molding Category”, [Online document], [Accessed: March 2009], Available at: http://www.kdcapital.com/Machines.cfm/ID/4009
  26. ↑ Trend Robotics, [Online document], [Accessed: March 2009], Available at: http://www.trendrobotics.com/products.php?list=C1
  27. ↑ Chicago Climate Exchange, [Online document], [Accessed: March 2009], Available at: http://www.chicagoclimatex.com/market/data/summary.jsf
  28. ↑ ”Customer FAQ”, [Online document]. Cogent Environmental solution [Accessed: March 2009] Available at HTTP http://www.ecogent.ca/index1.htm
Retrieved from "https://en.wikiversity.org/w/index.php?title=Design_for_the_Environment/All_Purpose_Residential_Cleaning&oldid=2305688"