Design Life-Cycle

 Lucie Mendoza

DES 40A

Professor Cogdell

Fall 2021

Diva Cup Life Cycle: Raw Materials

Introduction

Menstrual cups have become one of the most popular alternatives to tampons and pads today. Known for being reusable and eco-friendly, menstrual cups have been developed from different materials over the years. The first menstrual cups date back to the late 1800’s, made out of sacks and in some cases metal. Some of the early menstrual cups were designed to be worn with belts as well. Later on in 1937, American actress Leona Chalmers filed a patent for a more modern menstrual cup, using primarily rubber latex. This would be considered the first menstrual cup to be sustained by the holder’s pelvic muscles and was also to be sold commercially. One of the most popular menstrual cups to date is the Diva Cup which is primarily made of medical grade silicone. In this paper, we will be discussing the raw materials that are used in the production, reuse, and waste stages. 

Raw Materials Acquisition and Manufacturing

In order to understand how the Diva Cup is made, we must first get to know the materials used to make the product. In this case, the Diva Cup is majorly made of 100% medical grade silicone. The difference between silicone and medical grade silicone is that medical grade silicone must meet three requirements to be used biomedically: the silicone must successfully be able to work with animals and humans when implanted, must undergo its manufacturing process in good conditions in a pharmaceutical environment and must have medical quality in which it can be used in a medical field ("The chemistry and properties of the medical-grade silicon es."). 

In producing medical grade silicone, the first step is to separate the silica and silicon. Silica is one of the most common minerals found and can come from various ground sources such as beach sand and granite. After it has been reduced to silicon, the element is then reacted with methyl chloride. Methyl chloride can be found through natural processes in oceans or biomass in burning forested areas and grasslands. The outcome of this reaction is dimethyl dichlorosilane to which then water is added, forming a polymer. Hexamethyl disiloxane is then added to the mix making polydimethylsiloxane, this would leave the silicone in its liquid state however, in order to give its menstrual cup shape and the silicone must undergo the process of vulcanization. 

In order to complete this process, the silicone will be given a filler then a vulcanized agent such as dichlorobenzoyl peroxide. Combined with the heat of the oven (after being placed in one to complete the process), it takes high temperatures up to 1700 degrees Celsius for the menstrual cup to “cure and bond”(Quality Assurance). By completing this step, this will ensure that the Diva Cup’s elasticity will be able to mold into a desired size. After being molded in the oven, the Diva Cups are inspected, packaged into their box along with a pouch to carry on the go and a sticker to prove to the user that their Diva Cup is authentic. And finally, it is shipped and distributed. 

Distribution and transportation

The Diva Cup is manufactured and distributed in Kitchener, Ontario, Canada. This product is distributed internationally thus providing various modes of transportation for its distrubution. These include via aviation, marine transport, and land transport such as train or wheeled vehicles. The raw materials used in transportation modes such as these will use fossil fuels for land transport or petroleum based fuel for aviation transportation. With marine transport, aside from marine fuel being used to power transport, a more recent alternative is Shore Power. Shower Power is power that allows ships to be powered from land electrically when a ship is docked, reducing air emissions. (What is shore power and why does it matter?) Overall, various groups of primary and secondary raw materials are used in the processes of distributing and transporting the manufactured Diva Cups internationally from Canada. 

Use/reuse, Maintenance

In using the Diva Cup, little to no raw materials are being used when the user is using the cup. To start using the cup, the user must first boil the cup for 5-10 minutes (“Diva Cup Care and Cleaning”). This roughly estimates the water to be boiled at about 65 degrees Celsius. While the menstrual cup is in use, there are no raw materials needed. After every use, the user must empty the cup and wash the menstrual cup to keep good hygiene. The user then rinses the cup and washes the Diva Cup with a water based, unscented oil free wash to avoid any irritants for the user. Diva Inc also sells a Diva Wash that is oil free and unscented that way consumers can take the wash to go. The Diva Wash is made of ingredients such as water, sodium chloride, and cocamidopropyl betaine. With water and cocamidopropyl betaine being the main ingredients, the latter ingredient is coconut based as it can be derived from coconut oil and made into a synthetic fatty acid. It can also be found in other scent-free shampoo. Generally, the usage and reusing of the menstrual cup can also vary from each person who uses the Diva Cup, from how much water is being used when someone first purchase a Diva Cup to often they clean their cup to how much wash/shampoo is being used to clean the Diva Cup. 

Recycle

With the proper care of being washed at the appropriate times, the Diva Cup can last on average from six months to 10 years. Should the user use the incorrect wash or wash it regularly it can last for a certain time or should they do as instructed and recommended, the consumer will have the menstrual cup to its maximum time. Afterwards, the user has the choice of sending the Diva Cup to be recycled with Diva Inc.’s recycling program of Diva Recycles, who is paired with TerraCycle. TerraCycle is a waste management business that helps companies like Diva Inc. recycle their products through breaking down the recycled product and reusing the material for an alternative purpose. In the case of the Diva Cup, the processing of recycling the menstrual cup starts with washing down the collected cups then they are grounded down to powder where the material will be transferred and used to make more products such as athletic tracks and playgrounds. Not much information in regards to the raw materials used in this process could be found other than the already mentioned materials used to make the Diva Cup which, in this part of the life cycle, is being grounded to be reused. 

Conclusion

The raw materials used in the life cycle of the Diva Cup may have less amount of raw materials than other femmine hygiene products. It is reusable and can be recycled at the end of its cycle, however, with different materials come different processes and raw materials to construct the different menstrual cups. In conclusion, the Diva Cup may carry few raw materials throughout its life cycle but it doesn’t mean it doesn’t make an environmental impact during its production. From the acquisition of the materials like the quartz to make silca and the extraction of silicon the the heat processing, to the international distribution of the product seeing the air emissions expand. 

Works Cited

Hait, Amy, and Susan E. Powers. "Dataset: Feminine hygiene product lifecycle inventory and impact assessment." Data in brief 28 (2020): 104851 

Hait, Amy, and Susan E. Powers. "The value of reusable feminine hygiene products evaluated by comparative environmental life cycle assessment." Resources, Conservation and Recycling 150 (2019): 104422.

Peter, Anmiya, and K. Abhitha. "Menstrual Cup: A replacement to sanitary pads for a plastic free periods." Materials Today: Proceedings (2021).

Madziyire, Mugove G., Tsitsi M. Magure, and Chipo F. Madziwa. "Menstrual cups as a menstrual management method for low socioeconomic status women and girls in Zimbabwe: a pilot study." Women's Reproductive Health 5.1 (2018): 59-65.

Van Eijk, Anna Maria, et al. "Menstrual cup use, leakage, acceptability, safety, and availability: a systematic review and meta-analysis." The lancet public health 4.8 (2019): e376-e393.

Simtec. “How Is Silicone Produced?” SIMTEC Silicone Parts, 24 May 2017, https://www.simtec-silicone.com/how-is-silicone-produced/. 

Braley, Silas."The chemistry and properties of the medical-grade silicon es." Journal of Macromolecular Science—Chemistry 4.3 (1970): 529-544.

“Quality Assurance.” Diva International, 25 May 2020, https://divainternational.ca/quality-assurance/?_ga=2.129477900.1266636764.1636703121-2032073521.1636703121. 

“What Is Shore Power and Why Does It Matter?” Clear Seas, 18 Dec. 2020, https://clearseas.org/en/blog/shore-power-why-does-it-matter/. 

“Care and Cleaning: Washing Your Divacup: DivaWash.” DivaCup.com | Official Website for the World's #1 Menstrual Cup, 27 Oct. 2021, https://divacup.com/care-cleaning/. 

Boiling Water, http://jwilson.coe.uga.edu/EMT668/EMAT6680.2003.fall/Shiver/assignment12/Boiling%20Water.htm. 

“DivaWash: Divacup.com: Official Website for the World's #1 Menstrual Cup.” DivaCup.com | Official Website for the World's #1 Menstrual Cup, 17 Mar. 2021, https://divacup.com/products/divawash/#.

Embodied Energy:

Paloma Esparza

DES 40A - A2

Life Cycle Analysis Paper - DivaCup: Embodied Energy

Menstrual cups, specifically DivaCups, are a product that collects menstrual blood in a reusable silicone cup. The cups are folded and inserted into the vaginal canal where it expands to collect blood, similar to the way a cotton tampon is used. They can be used for up to twelve hours at a time. Due to the longevity and contiguity of the product, it is made with body-safe silicone. By using this material the product is able to endure use for two to ten years if properly taken care of. To clean it one must either use a silicone and body-safe cleaning solution or simply water. Once the product is at the end of its life, the cup can be disposed of in a landfill or sent to the proper channels that repurpose silicone products. DivaCups offer a more eco-friendly alternative to period products. In comparison to tampons and pads, the cup uses a material that is not widely used in other sectors of industry like cotton and plastic. The long-lasting aspect of the cup is also a major factor in the sustainability of the product, the energy used to make one cup is less than that which would be required for making multiple tampons or pads for a single cycle. In comparison to the competing options for period care on the market, DivaCup’s impact on energy consumption is impacting the environment significantly less. 

The DivaCup uses water and quartz as its primary raw materials. Water is used as a raw material by the consumer, post-production. Both materials share the same attributes, which are it is finite resource and requires a large amount of energy to use or extract. The product’s main raw material, quartz, is a very common material containing silicon and oxygen. It can be found naturally around the world with large deposits being in the United States and Brazil. However, the company does not publicly share where they source their raw materials from. The material’s chemical properties make it sensitive to high temperatures, so it is extracted through open-pit mining. This requires a large number of fossil fuels to run the machinery needed for its removal from the earth. Once it is extracted it must be refined in order to be used as a liquid silicone material. To do this the quartz must be ground up finely, almost to a powdery substance. Attrition or jet mills can be used to reach the desired size and consistency of the raw material. The mills require the use of fossil fuels to power the machinery. 

In comparison to single-use menstrual products, the energy involved in extraction and manufacturing is significantly lower. Products such as pads and tampons are traditionally made using cotton and plastic. Cotton requires human labor to grow and maintain, as well as the water used to feed the crops. Petroleum-based plastics are used in these products as a means to either seal or assist in using the product. Typically for pads, this refers to the wrapping used to seal a single-use liner. For tampons, it is also used for the wrapper and the applicator that houses the cotton material. When compared with the total energy used in raw materials, the DivaCup is about a third total of the energy used by tampons and sanitary pads. The use of finite resources and the energy required to process them make them less desirable from an environmental standpoint. 

Silicone is created from quartz that has been manipulated at the chemical level in order to reach the ‘rubbery’ state of a menstrual cup. This is done through the use of primarily fossil fuels to power the electricity needed to run silicone production factories. The quartz goes through a heating process along with carbon. The two are heated to temperatures, at the least, reaching fourteen hundred degrees celsius. Once the two have separated into pure silicon and carbon monoxide. First, the carbon monoxide gas must be disposed of properly to prevent poising of those in the factory. Next, the resulting silicon is ground up into a metallic powder and distilled with methyl chloride. The solution must react with water and then be stripped to create siloxanes. This substance is the chemical structure that allows for the material to be used in various ways. It is then polymerized and finally able to be shaped into the cup formation. During this stage of the process, a significant amount of energy is used to create the product. This is through the use of fossil fuels to power factories and machines. However, the most energy-consuming process is the transportation of the product to stores. 

Total energy consumption during the manufacturing process for single-use products and the reusable DivaCup are fairly comparable. Since the cup uses a material that requires a more extensive refining and production process, it requires more energy consumption. Whereas pads and tampons are made using more materials than the cup, there is a sizeable amount of energy used to process the product that is comparable to that of the cup.

Energy used in transportation is by far the most costly throughout DivaCup’s lifecycle. This is due to the fact that transportation heavily relies on the use of fossil fuels. Once the cup is produced and manufactured, it must go from place to place in order to get to the consumer. This is typically done via trucking and airplanes. The use of fossil fuels is a major contributor to the depletion of natural resources and greenhouse gas emissions. Alongside the widespread popularity of the product, the company’s market has largely increased since the beginning of the company. More cups are being transported globally, which increases the energy needed to power the vehicles. While the DivaCup is relatively low in energy use in all other aspects of the lifecycle, transportation is the area that excessively uses fossil fuels. This results in the overuse of petroleum products. 

When using a product like the DivaCup, which comes into close contact with many bodily fluids, it must be properly cleaned often. Since the cup is used so intimately, it requires proper cleaning well and often. This is done by rinsing the cup with every use. Due to the product’s long life, it requires constant use of water which exerts a large cumulative impact on electricity usage by the consumer. A person who menstruates would on average have a five to seven-day period. If they were using a menstrual cup, that would merit the need to clean the product about ten to fourteen times total over the course of one cycle. Energy use in this sector requires access to running water, which in turn is derived from nonrenewable sources of energy. In comparison to other period products, the menstrual cup requires energy input in its usage, very dissimilar to the use of tampons and pads. Water use in the maintenance of the DivaCup is a hindrance in the ease of use when compared to other products. 

At the end of consumer use, the DivaCup can either be tossed in the trash or properly recycled. When the cup is tossed in the trash, instead of recycling, it will end up in a landfill. This process requires transport from the consumer’s home until it reaches its final destination. With that, there is a need for fossil fuels to power the needed trucks and ships used in transportation. In comparison to other materials in dumps like plastics, silicone’s durability does not allow for it to degrade over time. This means that there is no chemical or microplastics leeching into the surrounding environment. However, it is still possible that the product can end up near areas where animals are heavily present and it can end up being digested. 

Body-safe silicone is able to be broken down and repurposed in materials used for a variety of things including recreation and construction. DivaCup encourages the sustainability of its product by promoting a recycling program for its cups. Once the cup is at the end of its life, the consumer can print a shipping label and send off their DivaCup to the company. There the cups are sanitized and pulverized until it becomes a fine powder. While it does expend energy through the shipping and breakdown process, the cup is then given a new life. Helping to prevent any excess energy or material use in another product. 

The DivaCup is made out of a reusable material that can last a single user years of use. In regards to energy use, there is a considerable amount of energy used to extract, manufacture, transport, and use the product. The majority of its energy consumption lies in transportation and raw materials. Transportation of goods requires a large number of fossil fuels to power ships and trucks. While water usage varies from person to person, the constant need for sanitizing accumulates a large amount of water use over time. However, when compared to other menstruation products, the DivaCup does not leave a large environmental impact in terms of resources and wastes. Single-use products require constant application of raw materials and energy to manufacture products. Which then go to a landfill after use, since plastic and used cotton are not able to be recycled. The DivaCup’s reusability and long life span inhibit the need for constant production of single-use menstrual products. The longer one cup is used, the more it prevents the need to overconsume raw materials and energy use, making it a viable alternative for menstrual care.

Works Cited

“The Chemistry behind Silicones - How They Are Made.” Silicones.eu, 23 July 2021, https://www.silicones.eu/the-science-behind-silicones-the-substances-used-to-manufacture-them/the-chemistry-behind-silicones-how-they-are-made/.

“Diva Recycling Program.” TerraCycle, https://www.terracycle.com/en-US/brigades/diva.

“Diva™️ Impact Report: Divacup.com: Official Website for the World's #1 Menstrual Cup.” DivaCup.com | Official Website for the World's #1 Menstrual Cup, 6 Aug. 2021, https://divacup.com/diva%ef%b8%8f%ef%b8%8f-impact-report/.

“How It Works.” TerraCycle US Zero Waste Boxes, https://zerowasteboxes.terracycle.com/pages/how-it-works.

“How Quartz Is Processed for Use in Everyday Products.” McLanahan, 30 Nov. 2021, https://www.mclanahan.com/blog/how-quartz-is-processed-for-use-in-everyday-products.

“Open-Pit Mining Definition.” Anglo American, 10 Dec. 2021, https://www.angloamerican.com/futuresmart/stories/our-industry/mining-explained/mining-terms-explained-a-to-z/open-pit-mining-definition.

“Products & Ingredients.” Diva International, 22 Apr. 2021, https://divainternational.ca/products/.

“Quartz.” Minerals Education Coalition, 7 Apr. 2021, https://mineralseducationcoalition.org/minerals-database/quartz/.

“Silicone: The Plastic Alternative: Eco-Friendly Topics on EarthHero Blog!” EarthHero, 19 May 2021, https://earthhero.com/silicone-the-plastic-alternative/. 

A M Muzafarov, et al. "New approaches in silicon production and recycling for sustainable future". Russian Chemical Reviews 82. 7(2013): 635–647.

Amy Hait, et al. "Dataset: Feminine hygiene product lifecycle inventory and impact assessment". Data in Brief 28. (2020): 104851.

Amy Hait, et al. "The value of reusable feminine hygiene products evaluated by comparative environmental life cycle assessment". Resources, Conservation and Recycling 150. (2019): 104422.

Gaines, L. L.. Energy and materials use in the production and recycling of consumer-goods packaging. United States: N. p., 1981. Web. doi:10.2172/6803439.

J. Jeswiet, et al. "Carbon emissions and CES™ in manufacturing". CIRP Annals 57. 1(2008): 17-20.

Köhler, H., and K. Trygg. “A Time-Geographical Mixed-Methods Approach: Studying the Complexities of Energy and Water Use in Households”. Fennia - International Journal of Geography, vol. 197, no. 1, Apr. 2019, pp. 108-20, doi:10.11143/fennia.68860.

M. Takla, et al. "Energy and exergy analysis of the silicon production process". Energy 58. (2013): 138-146.

Munksgaard, Jesper, et al. “TRANSPORT ENERGY EMBODIED IN CONSUMER GOODS: A HYBRID LIFE-CYCLE ANALYSIS.” Energy & Environment, vol. 16, no. 2, Sage Publications, Ltd., 2005, pp. 283–301, http://www.jstor.org/stable/43734723.

Waste & Emissions:

Taylor Jessen 

DES 40A: Energy, Materials & Design Across Time

Fall 2021

Diva Cup Waste & Emissions

The Diva Cup is a brilliant innovation in regard to renewable menstrual products. In comparison to other commonly available single-use menstrual products in the market (specifically o.b., Tampax, and Softcup), the Diva Cup expends considerably less emissions and has little to no environmental impact (Gendered Innovations: in Science). With reference to its life cycle, the Diva Cup’s environmental impact is strictly based on consumer behavior seeing that the transport and use phases of the cup constitute its most significant environmental impacts (Phillipa Notten). Not only is the Diva Cup heavier than commonly available single-use menstrual products in the market (pointing to its use of silicone which is a secondary raw material that emits a lot of energy to create vs. a raw material like cotton that is used for tampons), but it utilizes significant amounts of water in-between uses when compared to a single-use menstrual product, having to be washed at least two times per day. Although the Diva Cup is a compelling step towards renewable menstrual freedom, the detrimental waste and emissions caused throughout its life cycle are heavily overlooked by greenwashing campaigns, thus contradicting the Diva Cup’s renewable qualities (Amy Hait).

In a world where menstrual freedom is essentially nonexistent, the Diva Cup comes closer to annihilating this social problem by creating affordable, durable, and renewable menstrual products. From the extraction of raw materials to the waste and emissions given off by the Diva Cup, reusable/renewable menstrual products have substantially lower environmental impacts than their single-use counterparts (Phillipa Notten). The environmental impacts of the menstrual cup are insignificant in comparison to disposable products, with the renewable menstrual cup having less than 1.5% impact in comparison to that of tampons or pads. Even if just used for one month, the renewable menstrual cup has lower impacts than the single-use products, assuming that 20 pads or tampons are used in a month (Phillipa Notten). Although products like the Diva Cup in particular must be washed/sanitized at least two times per day (every 10-12 hours), they do not necessarily have to be washed with water every single time. Not only does this lead to less water waste, but it makes renewable menstrual products accessible to other societies/cultures that may not have easy access to fresh water (Nemeth). Despite the Diva Cup having substantially lower environmental impacts when compared to single used menstrual products, consumers must take into consideration the total environmental costs of the Diva Cup across all stages of its life cycle to truly determine the accuracy of its “renewable” qualities. 

Marketing schemes for reusable menstrual products are 100% reliant upon their “renewable” quality, or rather 100% medical-grade silicone in the case of the Diva Cup. 100% medical-grade silicone is a secondary raw material, meaning that the raw material that is extracted from the environment is then processed to create silicone. Silicone is never found in its natural state, but rather in combination with oxygen and other materials. Silica mining uses open pit/dredge mining methods with standard mining equipment which has limited environmental impacts besides temporarily disturbing the immediate area while mining operations are active. Since silicon compounds, in particular Feldspar and Quartz, are the most significant component of the Earth’s crust, this also makes them highly vulnerable to exploitation within a capitalist system that relies on the extraction and exploitation of raw materials (Coalition, Minerals Education). After obtaining silicon compounds, they are melted at 1700 degrees C and the compounds are then reacted with carbon. Once reacted with carbon, the silicon metal is ground down into a power and methyl chloride is then added (Council), Methyl Chloride is notorious for damaging environmental and bodily impacts, with exposure routes through: inhalation, skin and/or eye contact (CDC). After Methyl Chloride is added, silicon goes through a hydrolysis process where there is generally low-to-no-emission of volatile organic compounds emanating from the reactor and, in most cases, the products of the hydrolysis/hydration processes are biodegradable (Speight). The Diva Cup in particular emanates 0.2% emissions into water, 4.5% emissions into soil, and >95% emissions into the air (Council), therefore consumers must question its “renewable” characteristics.

It is imperative to understand the environmental impact of renewable menstrual cups, as their life cycle parallels other questionably “renewable” products and their accompanying life cycles within a capitalist system (where environmental resources are taken for granted due to the ongoing growth of consumerism, supply must keep up with demand). Seeing that consumer behavior is the key determinant behind the environmental impacts for both single and reusable menstrual products, the transport and use phases are key contributors to the environmental impact categories (Phillipa Notten). Since the Diva Cup is manufactured in Canada and has the ability to be shipped internationally, the transport phase may arguably be the most detrimental phase to the environment. In the year 2019 alone, Canada’s transport sector greenhouse gas emissions (freight- rail, aviation, marine, and heavy-duty trucks) accounted for practically half of all transport emissions, further meaning that the transport phase of the Diva Cup helped contribute to nearly 80 megatonnes of carbon dioxide within the Earth’s atmosphere. In addition to the transport sector, in the year of 2010 alone the Canadian electricity sector greenhouse gas emissions (coal, natural gas, other) accounted for nearly 60 megatonnes of carbon dioxide polluting Earth’s atmosphere (Greenhouse Gas Emissions: Canadian environmental sustainability indicators). During the use phase, specifically when the reusable menstrual cup is washed and sterilized by the consumer, the temperature/amount of water used and the type/amount of soap influences its environmental impacts (Phillipa Notten). In the end, it is clear that the Diva Cup’s environmental impacts are highly dependent on consumerism, with its most environmentally influential phases being manufacture, transport, and use; where each phase emits its own type of waste and/or emissions. 

The DivaCup in particular hosts its own recycling program in collaboration with TerraCycle, where consumers are able to recycle their used DivaCups’ (RubyCup). Although DivaCup offers this alternative in comparison to having one’s used menstrual cup ending up in a landfill (illegally), not everybody has access to it. In addition to this, the ability to recycle 100% medical grade silicone is essentially nonexistent through conventional methods, in turn making it nearly impossible for consumers to recycle their used DivaCups. In some cases, consumers have utilized their old DivaCups for gardening projects and/or recycled them through some type of re-design (after a thorough washing), but consumers must also remember that menstrual products are not biodegradable seeing that they are made up of secondary raw materials and therefore must be disposed of properly (RubyCup). The end of the life cycle for a DivaCup can go several different ways, but more often than not consumers aren’t aware of these recycling options which leads to their improper disposal and more waste/emissions into Earth’s atmosphere. 

In a capitalist society, the extraction of natural resources for profit comes with several constraints and limitations. The need for supply to keep up with demand not only sets the stage for higher rates of consumerism, but in turn higher rates of environmental destruction due to the need for more raw materials. This creates the façade that raw materials are essentially endless, when in reality we as a society are severely constrained by their limited quantities, especially with rising extraction rates and the ongoing spread of capitalism. Even though the end goal is a renewable product, such as for example the Diva Cup, this doesn’t necessarily mean that it embodies renewability (the same thing can be said about Tesla, where consumers may save energy during the use phase, but in reality every phase of the Tesla’s life cycle is utterly detrimental to the environment). Consequently, one must question the concept of renewability within a capitalist system and the romanticization of renewability when it comes to scoring a profit due to the fact that a majority of “renewable” products within our current capitalist system are equally, if not more, detrimental to the environment when compared to their “non-renewable” counterparts.

Works Cited

Amy Hait, Susan E. Powers. "Dataset: Feminine Hygeine product lifecycle inventory and impact assessment." 2020.

CDC. "NIOSH Pocket Guide to Chemical Hazards." CDC, 2019.

Coalition, Minerals Education. n.d. October 2021. <https://mineralseducationcoalition.org/minerals-database/silica/>.

Council, European Chemical Industry. Chemistry: Where do silicones come from? 2018. October 2021. <https://www.silicones.eu/the-science-behind-silicones-the-substances-used-to-manufacture-them/the-chemistry-behind-silicones-how-they-are-made/>.

Gendered Innovations: in Science, Health & Medicine, Engineering, and Environment. "Menstrual Cups: Life-Cycle Assessment." n.d.

"Greenhouse Gas Emissions: Canadian environmental sustainability indicators." Environment and Climate Change Canada, 2019.

Nemeth, Cole. How to Clean you Menstrual cup without running water. 25 September 2020. October 2021. <https://divacup.com/how-to-clean-your-menstrual-cup-without-running-water/>.

Phillipa Notten, Alexandra Gower, Yvonne Lewis. "Single-use menstrual products and their alternatives." 2021. Life Cycle Initiative. 2021. <https://www.lifecycleinitiative.org/wp-content/uploads/2021/07/UNEP-LCI-Single-use-vs-reusable-Menstrual-Products-Meta-study.pdf>.

RubyCup. How to Recycle a Menstrual Cup. n.d. October 2021. <https://rubycup.com/blogs/news/how-to-recycle-a-menstrual-cup>.

Speight, James G. Hydrolysis. n.d. 18 October 2021. <https://www.sciencedirect.com/topics/earth-and-planetary-sciences/hydrolysis>.