Design Life-Cycle

Lanhui Zhen 

Group members: Celene Moua, Paola Zaragoza Alcazar 

DES 40A 

Professor Cogdell 

March 16, 2023 

Materials in the Life Cycle of Gouache Paint

Gouache is often referred to as the in-between of acrylic and watercolor paint. This is because gouache combines the benefit of acrylic paint, which is being able to reach 100% opacity, and the benefit of watercolor paint, which can be rehydrated even after the paint has dried. These properties of gouache allow artists to paint translucently or opaquely depending on their needs and clean easily; it has been a favored medium among many plein-air artists (plein-air means to paint on-site, usually outdoor). This paper will address the materials that go into every step of the life cycle of gouache paint, from raw materials acquisition, to manufacturing, to transportation and distribution, to use and maintenance, to recycling, and to waste management. For the actual raw materials used in production, it will mainly be discussed in the first three steps of the life cycle. And for the rest of the paper, I will discuss the additional materials needed to paint with gouache, the recycling process both from the user and manufacturer’s perspective, and current issues with wastewater management in the paint industry. 

Raw Materials Acquisition 

The three basic materials that make up pretty much any paint are: pigments, solvent, and binder (“Ingredients Matter”). For pigments, there are two types: natural and synthetic. Natural pigments can be harvested from plants, insects, minerals, and earth (Landis). Plant pigments can be classified into four categories (Plant Pigments). Anthocyanin, which provides colors ranging from pink through scarlet, purple, and blue; carotenoids, which are responsible for colors ranging from yellow to bright red; chlorophylls, which accounts for the green pigments; betalains, provides colors ranging from yellow to violet (Plant Pigments). For insect based pigments, one of the most common ones comes from cochineal insects, and it provides a rich crimson red color. Another example is sepia color, which derives from squid ink! Earth pigments, also known as iron oxide pigments, are basically colored soil that got dug up and grounded into a fine powder (Hoffman). Blue pigments are rare in nature. However, many beautiful blue pigments can be found in minerals, such as cobalt and ultramarine. Synthetic pigments are produced through a chemical process. For example, the first Egyptian blue was created by heating a mixture of sand, limestone, salt, and iron dust. Although the nature of gouache paint is non-toxic, certain pigments contained within the paint can be toxic, such as cadmium and cobalt (Winsor & Newton). Artists should avoid using them as much as they can or find other alternatives. 

For solvent, gouache paint uses distilled water, which is a type of purified water. Distilled water is created through collecting the steam from boiling water (Blades). In this process, salts, minerals, and other organic compounds are removed, leaving with the “purest” form of water. Distilled water is used in instances where mineral buildup from regular tap water must be minimized. 

Binder helps bind the pigment powder together to give the paint its consistency. Different paints use different binder, like linseed oil for oil paint, egg for tempera paint, and acrylic polymers for acrylic paint. But for gouache paint, it uses gum arabic, which is made from the sap of Acacia senegal tree; most of these trees are grown in the Sudan region, Nigeria, Kenya, etc. (Grant).

Manufacturing, Processing and Formulation 

The formulation of gouache paint varies among different manufacturers. It was difficult to find the specific formulations from different paint brands because they are not disclosed to the public. But during the manufacturing process, in addition to the three basic ingredients (pigment, solvent, binder), other additives such as opacifier, preservative, plasticizer, and moisturizer are often added into the paint to enhance the final quality (Gurney). 

In order to achieve the opacity of gouache paint, an opacifier can be added. Some common types of opacifiers are calcium carbonate, titanium dioxide, talc, and marble dust. These opacifiers come in the form of white powder. This means that when an opacifier is added in, it can decrease the intensity of the paint color. Therefore, some manufacturers claim that they do not use any opacifier in their formulations, because these compounds are considered as relatively cheap paint fillers and they degrade the quality of the paint. Well-known paint manufacturers like Winsor & Newton and Holbein achieve the opacity in paint through pigmentation, which just means to use more pigment in the formulations. The paint will be less opaque, but it offers great saturation! The saturation of the original tube of paint is especially important for artists because artists can always mix in more white paint themselves if they want that opacity, but they will never be able to increase the saturation of the paint. However, certain pigments like ultramarine blue and phthalo green are naturally more translucent than other earth pigments like umbers and sienna (Gurney). In this case, some amount of opacifier is necessary to ensure that the paint has sufficient covering power expected from gouache. 

To prevent gouache from growing mold or other baterias, preservatives like benzisothiazolinone or antimicrobials are added for longer shelf life. Sometimes plasticizer is added to provide elasticity to the paint to help minimize cracking. According to Timothy Hopper, vice president of Holbein, they also add a moisturizer called polyethylene glycol to their gouache. But I couldn’t find what purpose a moisturizer serves exactly for paint. 

Distribution and Transportation 

After gouache is manufactured, it usually gets stored in an aluminum tube. Aluminum is a great material for making paint tubes because it’s affordable, lightweight, and malleable. According to Montebello’s Hawkesbury aluminum paint tube production, aluminum first gets coated with a lubricant called zinc stearate for stretching. After the aluminum gets shaped into the form of paint tubes and heated up for malleability, the inside of paint tubes will then get sprayed with two coats of epoxy lacquer as a protective barrier between the aluminum and the paint; the outside will be coated with polyester enamel paint for sun resistance. Then, paint tubes will get sent off to the printing machine for labelings. Finally, plastic caps will be screwed in and a strip of latex sealant will be sprayed inside the open end of the tubes. These packaging tubes will be sent to paint manufacturers. To prevent them from twisting during shipping, a sheet of sticky paper will often be placed over a box of paint tubes. The boxes used for shipping will usually be cardboard boxes because they are the cheapest kind. I couldn’t find the information on the full process of the distribution and transportation of gouache paint, but I would assume that it gets transported through cargo ships and trucks just like most items. 

Use / Maintenance 

In a typical painting session, in addition to gouache paint, an artist will need water, towel, brushes, color palette, water cup, and watercolor paper. Depending on the artist’s practice, the longevity of these materials may vary. Some beginner artists might prefer to use plastic cups to hold their dirty paint water while more advanced artists might prefer to go for more sustainable options, like ceramic cups. In addition, the quality of art supplies matters! The cheap paint brushes from Dollar Tree are likely to start shedding after the first couple of uses. This means that artists will have to replace them more often. However, even if the artist does buy high quality art supplies, it also depends on whether the artist knows how to take care of them. For example, a watercolor brush bought for gouache painting is later used for acrylic paint can ruin it immediately, because acrylic paint residue will dry hard. 

Recycle 

Generally, there is not much recycling for gouache paint at the users’ end of life cycle. Paint will either get all used up or dried up. Because a tube of gouache paint is relatively small and cheap, it does not worth the time and effort to send to a recycling center. Therefore, people will generally just toss them away in the trash. However, on the manufacturers’ end, more and more factories are now recycling expired paint and using them as an alternative energy source for other industrial applications (Productcare Recycling). For the packaging, aluminum is an extremely recyclable material; it can virtually be recycled infinitely through melting and reshaping (“How Are Aluminum Cans Recycled”).  

Waste Management

At the end of the life cycle of gouache paint, the main concern is wastewater management. Unlike oil paint, gouache is a non-toxic paint, which means that the waste doesn’t need any special disposal and can be dumped into the drain like typical household waste. The wastewater will then get treated the same way through the municipality. As I dived more into the wastewater treatment process, I found that just by itself can be a very broad and complex topic; it will probably require another paper to explain it. But to summarize, there are three main types of wastewater treatment methods: physical treatment, chemical treatment, and biological treatment. Physical treatment can filter out any debris from wastewater; chemical treatment uses chemicals to separate or convert pollutants as a result of chemical reactions; biological treatment removes biodegradable, soluble, organic, and nutrient substances from wastewater (Shojaei). 

It was difficult to find information about wastewater treatment for gouache paint, so I looked to the paint industry in general. Currently, wastewater treatment methods specifically targeted to the paint industry are still being developed, but the main concern is the heavy metal buildups in wastewater as they can be extremely polluting to the environment (Manu and Azhoni). 

Conclusion 

As a designer, gouache has been a favorite medium of mine. It looks so simple at first glance. But as I dived deeper into the life cycle, I learned that there are so many raw materials needed to be harvested for just a simple tube of gouache; formulas of paint have to be carefully developed for each specific color; waste management methods need to be continually developed to minimize the environmental impact. 

Works Cited

Author links open overlay panelM.A. Gondal a, et al. “Determination of Poisonous Metals in 

Wastewater Collected from Paint Manufacturing Plant Using Laser-Induced Breakdown

Spectroscopy.” Talanta, Elsevier, 18 Apr. 2006,

https://www.sciencedirect.com/science/article/pii/S0039914006002207. 

Author links open overlay panelSurya Nair K, et al. “Sustainable Treatment of Paint Industry

Wastewater: Current Techniques and Challenges.” Journal of Environmental

Management, Academic Press, 30 June 2021,

https://www.sciencedirect.com/science/article/pii/S0301479721011671. 

“Cheap vs. Expensive Watercolor Art Supplies - Is It Really Worth It?: Art Journal Thursday EP. 

30.” YouTube, 11 Jan. 2018, https://youtu.be/BlPiCAQ_MJM. 

“Distilled Water Overview.” WebMD, WebMD,

https://www.webmd.com/diet/distilled-water-overview. 

“Gouache Ingredients: Info from Manufacturers.” Gurney Journey,

http://gurneyjourney.blogspot.com/2015/06/gouache-ingredients-info-from.html. 

“Gouache.” Gouache | BLICK Art Materials,

https://www.dickblick.com/categories/painting/gouache/. 

Grant, Bonnie L. “Gum Arabic Information - Where Does Acacia Gum Come From.” Gardening 

Know How, 23 July 2021,

https://www.gardeningknowhow.com/ornamental/trees/acacia/acacia-gum-acacia-gum-uses-history.htm. 

“How Natural Pigments and Dyes Have Been Used in Art.” Invaluable, 11 Sept. 2018, 

https://www.invaluable.com/blog/natural-pigments/. 

Landis, Holly. “Drawn from Nature: A Guide to Natural Pigments.” Skillshare Blog, 30 Aug. 

2022, https://www.skillshare.com/en/blog/drawn-from-nature-a-guide-to-natural-pigments/. 

“Paint Recycling: How It Works.” Product Care Recycling, 2 Mar. 2023, 

https://www.productcare.org/about/blog/how-is-paint-recycled/. 

Pioneer Athletics. “Ingredients Matter: The Basics of Paint: Blog: Pioneer Athletics.” Blog | 

Pioneer Athletics, Pioneer Athletics, 19 Sept. 2019,

https://pioneerathletics.com/blog/ingredients-matter-the-basics-of-paint. 

“Plant Pigments.” Plant Pigments - an Overview | ScienceDirect Topics, 

https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/plant-pigments

#:~:text=2%20Natural%20colorants%20from%20plant,naturally%20derived%20colors%

20from%20plants. 

“Wastewater Treatment.” Wastewater Treatment - an Overview | ScienceDirect Topics, 

https://www.sciencedirect.com/topics/earth-and-planetary-sciences/wastewater-treatment. 

“What Are Earth Pigments? A Guide to Ochres, Oxides, and Minerals.” Natural Earth Paint, 

https://naturalearthpaint.com/blogwhat-are-earth-pigments-a-guide-to-ochres-oxides-and-

minerals/. 

“Winsor & Newton Designers Gouache.” Winsor & Newton Designers Gouache | BLICK Art 

Materials, https://www.dickblick.com/products/winsor-newton-designers-gouache/. 

YouTube, 7 Oct. 2016, https://youtu.be/3jOFYDWRHxM. Accessed 14 Mar. 2023. 

YouTube, 9 Nov. 2019, https://youtu.be/UwjieN8Dul0. Accessed 14 Mar. 2023. 

YouTube, YouTube, 13 Mar. 2021, https://www.youtube.com/watch?v=Q7Z2lttME1c. Accessed 

14 Mar. 2023. 

YouTube, YouTube, 20 Jan. 2011, https://www.youtube.com/watch?v=8yOqFbygVAQ. Accessed 

14 Mar. 2023. 

YouTube, YouTube, 21 Sept. 2018, https://www.youtube.com/watch?v=KmMP67eC2tg.

Accessed 14 Mar. 2023. 

Energy

Gouache is a water medium paint that has versatility like watercolor but can be opaque like acrylic. It can be in a jelly form in containers or a paste in tubes which is the most common form. Its contents contain pigment, a binder like gum arabic, and a white substance like chalk to make the colors opaque. Gouache is known as an environmentally friendly paint alternative due to its earth-friendly components, however, the energy used put into extracting the materials, packaging, and transporting is not environmentally friendly. Energy is constantly being used by extracting Arabic gum for the gouache or obtaining pigment for the packages it’s held in and the shipping across seas and distribution to stores. 

Raw Materials Acquisitions

Energy consumption for obtaining raw materials uses thermal, mechanical, chemical, and electrical energy. One of the main ingredients for Gouache, which makes paint stick to the paper as the water dries, is gum Arabic. Gum Arabic is a sap extracted from specific acacia Senegal trees. Mechanical energy is used to peel back the bark of the tree or to pierce tools into the tree so the sap can leak out. As the sap leaks out and dries up, it will be collected to sit out on drying racks and then processed through grading, sanitation, and filtration. Lastly, thermal energy will melt down the gum Arabic to emulsify it into a gel.(Niranjan Prasad et al.) Pigments go through chemical energy as they form into a solid as they’re made in labs like synthetic pigments. Natural and synthetic pigments consume similar energy as gum arabic. All pigments are collected and made manually. For example, natural pigments made of bugs, dried plants, or soil have to be collected. Machines will dehydrate the natural resources while people sieve through the products before being crushed into a fine powder. To get pigments to a fine powder it is crushed up by machines that use electricity and are heated sometimes to change the pigment hue. Synthetic pigments are manually made by manipulating their chemical process with thermal energy. For example, Egyptian blue, one of the oldest synthetic pigments, is a mixture of sand, natron, and bronze or copper shavings which are formed into balls and put into a furnace. When it comes out of the furnace the mixture solidifies and then ground into a pigment. 

Manufacturing

When the raw materials are gathered and collected they are sent to factories where they'll be mixed and packaged. The factories run on nonrenewable materials and energy to keep them working. This energy provides electricity for machines to combine the pigments along with the binder (Arabic gum). 

In Montebello's Hawkesbury distribution aluminum tubes start off as slugs, coin shape size, and are put into tumblers to be coated in zinc stearate even and then machine distributed to be pressed. The slugs are lined horizontally and enter a stage called impact extrusion where 200 tons of pressure is applied to create a sired thickness and length. Compressed air aligns the tubes to be trimmed by machine and heated to soften the metal in order to be internally coated by a protective lacquer. The tubes are then coated in paint and printing labels and put into the oven to dry. They are then lined internally with a latex sealant at the end of the tube and capped with a lid. Finally, the tubes are packaged and manually checked for their quality to be shipped off for use.  Like the aluminum tubes, the plastic holders for the package are molded by heat so the paint tubes can be stored in them.

Transportation and Distribution

After being manufactured it is ready to be transported and shipped to stores that will seal the paints. Transportation and distribution are one of the many parts of the lifecycle that consumes the most energy because vehicles, cargo ships, and planes all use non-renewable fossil fuels. The amount of energy used depends on where factories are located and where the products end up being sold. However transportation doesn’t begin after the gouache paint has been combined and packaged up and ready to ship off, it begins once the raw materials are gathered. Vehicles use an average of 4.5L of diesel fuel for every 100km. (Brito et al.) On a much larger distribution and transportation scale, cargo ships use the most amount of energy. 37% of the energy is converted to work for the main engine. (Tadeu, 2019, pg.34) 

Reuse and Maintenance 

Gouache is fairly easy to maintain and reuse because it is water soluble. Like watercolor, it can be reactivated when it comes into contact with water. There isn’t much energy put into gouache itself besides mechanical energy. The person using the paint will use their energy to control the product. However, the energy is mainly focused on water use. When using gouache people get water from the faucet. Chemical and electrical energy is used to keep the water clean for human consumption and use. Water undergoes chemical filtration and uses thermal energy like heat to eliminate any harmful pathogen that may reside in it. However to keep water running and safe to use, chemical energy is used to make electrical energy that keeps machines running and filtering. “To lift 100 m3 of water per minute to a height of 100 m requires more than 1.5 MWe of power if the pumps are 100% efficient. To do this continuously for a year using electricity from a typical oil-fired power plant and pumps that are 50% efficient would require the energy content of nearly 50,000 barrels of oil.” (Gleick, 1994, 270) 

The energy put into water varies depending on the location of the water source. Not everyone and every factory have its water source next to them so they take it from somewhere else. “Most long-distance water-transfer systems have both pumps for getting water over hills and mountains and hydroelectric generators to take advantage of the energy in the falling water as it comes down the other side. Whether a system is a net consumer or producer of energy depends on its geographical characteristics. Where additional energy must be supplied, it is typically generated with fossil-fuel or nuclear facilities, adding to the environmental costs of the water diversion itself.”(Gleick, 1994, 270) 

Recycling 

Goauche the paint itself can be washed down the drain or poured out onto soil because most of its ingredients are eco-friendly, and naturally derived from the earth. However, the water will have to go through the same steps of filtration and sanitation to be used again. Aside from the gouache itself, its counterparts like the aluminum tube along with the plastic and cardboard packaging have to be recycled. 85% of the aluminum can be recycled. “The energy required to remelt aluminum is 5% of the energy required for its primary production.” (Green, 2007, pg.114) Cardboard and paper that are included in the packaging require energy for their processes like incineration and electricity for applying pressure. However, Villanueva, Alejandro, and Wenzel state that virgin paper “uses more energy because it requires the harvesting of wood and a pulping process, followed by refining and drying.”(2007) Most of the energy used is put into the technology that processes the cardboard and papers. As mentioned before, cargo ship consumes the most energy for transportation and distribution. However, not all the energy consumed is recycled. “29% of energy is transferred to exhaust gas, part of this energy is recovered by exhaust gas economizers producing steam for heating needs.” (Tadeu, pg.34) 

Waste Management

In the manufacturing process aluminum tubes are formed by heat and pressure, however, a lot of the energy is lost in heat. Aluminum factories are energy intensive and release a large proportion of energy to the atmosphere in the form of waste heat”. (Brough and Jouhara, 2019) For products like aluminum, natural pigments, Arabic gum, to cardboard boxes energy is used and energy comes in different forms. Heat is used to manipulate the shape and forms of contents. Heat can also be used to get rid of materials in landfills. Another form of energy is water which is used to grow trees like the acacia Senegal tree that produces sap or compost cardboard boxes for recycling. “Water is required when an energy resource is mined, as a feedstock to alter fuel properties, for the construction, operation, and maintenance of energy-generation facilities, for power-plant cooling, and for the disposal of waste products.” (Gleick, 1994, p.268) With transportation playing a significant role in product making 34% of the cargo ship fuel energy “is wasted into the environment through the cooling systems, shaft frictions, and radiations.” (Tadeu, 2019, pg.34)

Conclusion 

In conclusion, gouache requires three main ingredients; pigments, opacifiers, and water. However, the simplicity of Gouache paint isn’t the same as the amount of energy put into their counterparts. The amount of energy used for material acquisition, transportation, manufacturing, and recycling outweighs the energy used for the maintenance and reuse of the product. Even for maintenance, and use, using manual labor to mix gouache with water doesn’t use large amounts of energy as maintaining water. 

Bibliography 

Abdallahaijjou, LHOUSSAIN BAHATTI, and A. B. D. E. L. H. A. D. I. Raihani. "Study on container ship energy consumption." Energy Sustain. VIII 237 (2019): 25.

“Ancient Color.” Ancient Color | Creating Blue, exhibitions.kelsey.lsa.umich.edu/ancient-color/blue.php. 

Brito, F. P., et al. “Página Principal.” Reposit�RiUM, Nova Science Publishers, 1 Jan. 1970, http://repositorium.uminho.pt/handle/1822/26392. 

Brough, Daniel, and Hussam Jouhara. "The aluminum industry: A review on state-of-the-art technologies, environmental impacts and possibilities for waste heat recovery." International Journal of Thermofluids 1 (2020): 100007.

Gleick, Peter H. "Water and energy." Annual Review of Energy and the environment 19.1 (1994): 267-299.

Green, John AS. Aluminum recycling and processing for energy conservation and sustainability. ASM International, 2007.

“‘How It's Made’ Featuring Montebello Packaging.” YouTube, YouTube, 20 Jan. 2011, www.youtube.com/watch?v=8yOqFbygVAQ. 

Niranjan Prasad, et al. “Gum Arabic – a Versatile Natural Gum: A Review on Production, Processing, Properties, and Applications.” Industrial Crops and Products, Elsevier, 7 July 2022.

Tadeu, A. (2019). Energy and sustainability Viii. WIT Press. 

Villanueva, Alejandro, and Henrik Wenzel. "Paper waste–recycling, incineration or landfilling? A review of existing life cycle assessments." Waste management 27.8 (2007): S29-S46.

Waste

 Paola Zaragoza 

Design 40A

Mar 15, 2023

Waste of Gouache Paint

Gouache paint is a type of paint that is a mixture of watercolor and acrylic paint.  Gouache paint differs from watercolor and acrylic paint because it's as pigmented as acrylic and can be reactivated with water once it dries, unlike watercolor. But most people don’t consider how and what gouache paint is made and its environmental impacts. The majority of waste in gouache comes from energy and transportation and from raw materials in the form of carbon emissions and run-off that contributes to significant environmental and social impacts, such as global warming. This paper aims to inform people of the waste that comes from producing gouache paint in all the stages of the product's life cycle. 

Raw materials

Gouache paint is made using natural or synthetic pigments, water, and gum arabic (“What Is the Difference Between Gouache and Acrylic?”). Gum arabic is sourced from the acacia tree, which has to be cut down to get the sap needed to create the gum arabic. Sudan is the biggest producer of gum arabic, and this can be due because the acacia tree grows better in tropical climates(“Gum Arabic Company”). Pigments are what give the paint its color, and there are organic and synthetic pigments. Synthetic pigments are acquired through coal tars and petrochemicals(Metych). Petrochemicals are chemicals made using fossil fuels like coal, natural gas, and oil. The bad thing about petrochemicals is that they are bad for the environment. Petrochemicals release a lot of carbon emissions, a total of 1.5 gigatonnes of CO2 in 2018(Gallacher). Petrochemicals can also be harmful if released into the environment on land and in water because it's very toxic. It can harm aquatic life or the soil(Gallacher). Like petrochemicals, coal tars also harm the environment. Coal tars are a byproduct of coke extracted from coal (“Coal Tar”). Coal tar can be hazardous to aquatic and human life due to its high chemical polycyclic aromatic hydrocarbons concentration if it gets into run-off waste(“Environmental Impact of Coal-Tar Pitch”). 

Manufacturing, processing, and formulation

Gouache paint is typically packed in tubes made of aluminum because it's cheaper and malleable. The tube labels must be coated in polyester enameled paint because it's resistant to most solvents and sun damage(“How it’s made”). It can be very toxic when applied to the tube, but okay once it fully dries (Dadd), which is why machines apply the paint. Since its toxic while applied, it can harm humans by inhaling it. After it is covered in the polyester enameled paint, the tubes, a machine applies the label using a printing plate that rolls the label onto the tube. It is then heated in an oven for the ink to dry. After the tubes are dry, they are then capped with plastic caps. The caps are not good because plastic packaging, like caps, emitted 3.4% of greenhouse gas emissions in 2019(“Plastic Leakage and Greenhouse Gas Emissions”).   

Distribution and Transportation

For the tubes of paint to be distributed to places worldwide, transportation like cargo trucks and container ships are needed since different gouache paint companies have their gouache paint made in other parts of the world. Container ships carry goods from all over the world in big boxes made of steel to get them to their destination. In 2020 container ships emitted 140 million metric tons of carbon dioxide, and general cargo ships emitted 40 million tons(Tiseo). Once the ships reach the port, they need tractor-trailers to pick them up to get them to their next destination. These tractor-trailers contribute more to greenhouse gas emissions because they make up 7% of the greenhouse gasses emitted in the United States in 2020 and are predicted to increase in the next few years(O’Connor).      

Use, Re-Use, and Maintenance

Gouache paint is easy to reuse since it can be reactivated with water even if it was left out and dried for a while. It’s a very versatile medium. Because of this, gouache paint is easy to keep using repeatedly. This is primarily because gouache paint is water-based. Even after the gouache paint has been dried and reactivated, it doesn’t lose its pigmentation and can become less opaque by adding more water to make it look more like watercolor. The only waste from usage is the gouache water paint because some gouache paints can contain toxic chemicals and shouldn’t be poured down the drain.  

Recycle

The tubes of gouache paint can be recycled depending on the recycling center and its rules. For example, some recycling centers accept metal paint tubes/tins, but some might require the tins and tubes to be cleaned before being recycled. And some Recycling centers may not accept paint tubes/tins(Okello). In addition, the plastic caps on the paint tubes are hard to recycle since plastic is hard to decompose since bacteria cannot break them down(Elkins). The plastic caps are also too small and can get stuck between the gears of the machinery in the recycling process (Davis). 

Waste Management

To dispose of the water used for painting with gouache paint, it's better not to pour it down the drain because the ingredients used within the paint can be toxic and harmful to the environment(“How to Dispose of Gouache Paint”). Due to components such as synthetic pigments made using petrochemicals and coal tar. Some gouache paint can contain harmful, toxic chemicals such as lead and cadmium(Yadro). And if the gouache paint water is poured down the drain and it has cadmium, it can cause harm to aquatic life if it ends up in the water. Cadmium is also harmful to human health because of its toxicity. Humans can be exposed to cadmium by breathing or eating it. Even lower exposures over time can cause health problems such as kidney disease, lung damage, and death and have been found to be linked to lung cancer(“Cadmium”).  As for lead, if the water containing lead was to be discharged into bodies of water, it could impact the ecosystem around there. It can reduce the growth and reproduction of both plants and animals(“Basic Information about Lead”).

Conclusion

The waste of gouache paint, through the cycles of raw materials, energy, and final disposal, can end up in landfills, oceans, and the air. But the part of the cycle that is the most significant contributor to waste is during the raw materials process since it takes fossil fuels to create the synthetic pigments for the paints. And transportation and distribution emits a lot of carbon emission because vehicles like cargo chips, trailer tractors, and cargo trucks are used to get goods worldwide alone. Thus while gouache paint is generally not toxic to humans, it doesn’t mean it doesn’t impact the environment throughout its life cycle as a product.  

Bibliography

“What Is the Difference Between Gouache and Acrylic?” Online Art Supplies Store, King's Framing and Art Gallery, 31 Dec. 2021, https://www.kingsframingandartgallery.com/blog/post/gouache-vs-acrylic. 

“Gum Arabic Company (GAC) - Age (African Growing Enterprises) File.” IDE-JETRO, Institution of Developing Economies Japan External Trade Organization, https://www.ide.go.jp/English/Data/Africa_file/Company/sudan06.html. 

Metych, Michele. “Synthetic Organic Pigment.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., https://www.britannica.com/technology/pigment. 

Gallacher, Paula. “What Are Petrochemicals and Why Are They Bad?” Cove Cleaning, Cove Cleaning, 1 Feb. 2022, https://cove.cleaning/blogs/blogs/what-are-petrochemicals-and-why-should-we-avoid-them. 

“Coal Tar and Coal-Tar Pitch - Cancer-Causing Substances.” National Cancer Institute, NIH National Cancer Institute, 5 Dec. 2022, https://www.cancer.gov/about-cancer/causes-prevention/risk/substances/coal-tar.  

“Environmental Impact of Coal Tar Pitch - Ecoshield Asphalt.” Eco Shield, Eco Shield Asphalt Products, https://ecoshieldasphalt.com/news/environmental-impact-of-coal-tar-pitch/.  

“‘How It's Made’ Featuring Montebello Packaging.” YouTube, YouTube, 20 Jan. 2011, https://www.youtube.com/watch?v=8yOqFbygVAQ.  Accessed 13 Mar. 2023. 

 Dadd, Debra Lynn. “Polyester Enamel Paint on Metal.” Debra Lynn Dadd, 1 May 2014, https://www.debralynndadd.com/q-a/polyester-enamel-paint-on-metal/.  

“Plastic Leakage and Greenhouse Gas Emissions Are Increasing.” OECD, 2019, https://www.oecd.org/environment/plastics/increased-plastic-leakage-and-greenhouse-gas-emissions.htm.  

O'Connor, Timothy. “100% Zero-Emissions Trucks. How Close Are We?” Environmental Defense Fund, 16 Sept. 2020, https://www.edf.org/blog/2020/09/16/100-zero-emissions-trucks-how-close-are-we.  

Tiseo, Ian. “International Shipping: CO2 Emissions by Ship Type 2020.” Statista, 6 Feb. 2023, https://www.statista.com/statistics/216048/worldwide-co2-emissions-by-ship-type/. 

 Okello, Joel. “How to Dispose of Acrylic Paint Safely.” PaintsAcrylic, 2 May 2022, https://paintsacrylic.com/how-to-dispose-of-acrylic-paint/. 

Elkins, Zeke. “Why Is It so Hard to Decompose Plastic?” Columbia Daily Tribune, Columbia Daily Tribune, 7 Jan. 2019, https://www.columbiatribune.com/story/lifestyle/family/2019/01/07/why-is-it-so-hard/984920007/.  

Davis, Rebecca, and Christopher Joyce. “Plastics: What's Recyclable, What Becomes Trash - and Why.” NPR, NPR, 21 Aug. 2019, https://apps.npr.org/plastics-recycling/.  

Yadro, Cecile. “Is Gouache Toxic?” Cecile Yadro, 19 Nov. 2022, https://cecileyadro.com/is-gouache-toxic-2/#:~:text=Gouache%20is%20a%20type%20of,considered%20to%20be%20non%2Dtoxic. 

“How to Dispose of Gouache Paint.” Blended Canvas, 17 May 2021, https://blendedcanvas.com/how-to-dispose-of-gouache-paint/.

“Cadmium.” NewTech Recycling, NewTech Recycling Corporate Electronics Recycling, 21 Mar. 2022, https://newtechrecycling.com/glossary/cadmium/#:~:text=It%20is%20necessary%20to%20ensure,recycling%20center%20like%20Newtech%20Recycling.  

“Basic Information about Lead Air Pollution.” EPA, Environmental Protection Agency, 26 July 2022, https://www.epa.gov/lead-air-pollution/basic-information-about-lead-air-pollution.