1. Introduction
With the rapid development of the living standard in China, the demand for cosmetics has grown steadily in recent years. The pursuit of external beauty and a delicate impression may become the major drives after the rise in living conditions, along with economic growth. Cosmetics are switching their role from alternative merchandise to daily necessities underpinned by thriving e-commerce.
As
Figure 1 shows, the retail value of the cosmetics category in China kept growing from 2018 to 2021. Current period values illustrated there were three sales peaks in one year, March, the period after the Chinese New Year, June and November, and two shopping festivals, 618 and Double 11. The year-on-year and cumulative growth rates were greater than zero in most of the period; it only dropped below zero during the initial stage of the COVID-19 epidemic period, from January to June 2020, and grew again after the epidemic was under control; moreover, a huge growth appeared in March 2021. A notable growth in retail sales can be predicted. Accordingly, cumulative values presented an increasing trend as the peaks were higher and higher yearly [
1].
Meanwhile, a male consumption consciousness of cosmetics is awakening recently; 10 million units of merchandise were stocked for Double Eleven Shopping Day in 2020, which was almost twice as much as in 2019. In addition, imported cosmetics for men have grown rapidly, by nearly 3000%; a previous report has shown that 31% of men expressed they would never use them, but the proportion had decreased to 10% in 2019 [
2]. Skincare products for men increased by 30% in 2020 [
3].
With the rapid rise in sales, waste of cosmetic packaging after the use stage increases at the same time. Furthermore, a shift from reusable packaging to single-use one due to globalisation and simplification of the supply chain is observed [
4]. The relationship between humans and the environment deserves deep consideration under the background of the circular economy. Reducing the environmental impact of the packaging during the whole life cycle through a recycling-oriented material selection, reasonable purchase and consumption, instructive recycling and reuse is the pursuit of the circular economy [
5].
Life Cycle Assessment (LCA) is a powerful tool for quantitative research on the sustainability of a system or product as an observer; it has been used to evaluate the environmental impact of a set of raw materials for packaging, including wood and plastic material [
6], PET bottle [
7], biomass-based and oil-based plastics [
8], beverage packaging [
9], multilayer polymer bag [
10] and bio-plastic for food packaging [
11]. LCA is also recommended by Escursell et al. [
12] as a tool to verify the environmental performance of the new solutions for packaging design. Sustainable or ecological design becomes more effective if working with LCA. Civancik-Uslu et al. [
13] used LCA to figure out the key life cycle stage of cosmetic packaging to implement eco-design is the raw material production and recycling; in the case study, mineral fillers are partially used for production instead of virgin petrochemicals to reduce the eco-impact of the packaging.
So far, most of the research on the sustainability of packaging mainly focuses on food-related products, because it is strongly associated with human daily health. Numbers of research on the sustainability of cosmetics put attention on the ingredient choices and production but not the packaging aspect [
14,
15]; however, in some specific scenarios, the packaging generates more impact than the ingredient extraction [
16], and it should be brought to the forefront now.
Reuse and recycling play important roles in sustainable packaging. Well-designed, refillable and reusable packaging, considering re-sealability, user-friendliness, and choice of material, can reduce environmental impact [
4,
17]. In addition, reuse has a greater effect than recycling, as the latter depends on consumer recycling behaviour [
18,
19].
However, a study illustrates that purchasing and recycling behaviours of consumers depend on their environmental awareness, positive attitude to green purchasing, etc. [
20]. The question is that consumers evaluate packaging through subjective feelings to design, graphics, material, and supposed recyclability [
21,
22]; besides, they can be easily misled by salient cues that may not reflect actual environmental impacts. Two recent pieces of research indicated that consumer perceptions do not align with LCA results; plastic is underestimated, and glass and biodegradable plastics are overestimated [
21,
23].
Furthermore, some sustainable packaging has eco-label, but consumers have limited knowledge [
22]. A survey reveals that urban consumers had an overall low perception of carbon-labelled products in Chengdu, China, which will influence purchase behaviour significantly [
24].
Several studies show a set of potential solutions for filling the gap between consumers and sustainable packaging. Sustainable packaging needs to be designed with good communication and interaction, to highlight the environmental benefits of the product and the packaging, and to inform consumers of the proper way to reuse and recycle, and how their behaviours can contribute to reducing the environmental impact [
21,
25,
26].
On the other hand, robust modelling of the use phase considering consumer behaviour is crucial during the LCA and sustainable design. Intervention that changes consumer behaviour generated by redesigning the packaging will be a good approach for reducing the impact [
27].
In other words, the designer can influence consumer purchase, consumption, recycling and reuse behaviour through the sustainable design approach. Therefore, the design phase is a crucial life cycle stage for cosmetics because the environmental impact of other stages and the whole system are generally defined at this phase; this means it has a higher decisive effect on the environmental performance of the product than other stages [
28].
This research aims to figure out to what extent sustainable design influences the environmental performance of the packaging and propose a set of sustainable design strategies for cosmetic packaging through the following processes:
To perform a literature review on aspects of cosmetic packaging design, sustainable design, consumer behaviour and LCA.
To conduct LCA of a group of representative cosmetic packaging according to the product that an international leading cosmetic company put on the China market in 2021, and figure out the main contribution to the environmental impact and opportunities for sustainable design.
To propose a series of potential scenarios for improving the environmental performance from aspects including recycling, material use, appropriate use, transportation, and direct reuse. To evaluate the improved concepts through LCA and sensitivity analysis.
To evaluate the significance of these variables in scenarios to the sustainable design of these cosmetic packaging through sensitivity analysis.
To propose a set of sustainable design strategies for cosmetic packaging.
4. Discussion
From the results of the LCIA comparison, No. 3 has the lowest impact of all, 366.20 mPt. No. 2 generates the highest impact, 609.20 mPt. No. 1 has a slightly higher impact than No. 3, 401.18 mPt; it indicates that these two bottles made of plastic have better environmental performance than the one made of glass under the circumstance described in the research. No. 3 and No. 1 generate 60.11% and 65.85% environmental impact than that of No. 2, respectively. In other words, it has the potential for decreasing from 35% to 40% impact.
Based on the findings from LCIA networks, reducing the impact generated by sanitary landfills is the most crucial task to improve the environmental performance of these cosmetic packaging bottles. Alternatively, reducing the impacts from manufacture, transportation, and incineration are optional implementations.
In order to develop the sustainable design strategy, the following sensitivity analysis scenarios are conducted to figure out to what extent these scenarios influence the sustainable performance of the packaging, or the significance of these variables to the sustainable design of these bottles. The variation range is from −20% to +20%. The amount of variation is 10%.
Scenarios and variations for the sensitivity analysis are shown in
Table 6.
To increase or decrease the recycling rate of bottles. Accordingly, to decrease or increase the rate of landfill.
To increase or decrease the material use in manufacture.
To increase or decrease the usage amount of users.
To increase or decrease the transoceanic transportation distance.
To increase direct reuse by users. The variation is assigned as 10% and 20% for the purpose of sensitivity analysis and comparison with other scenarios. In practice, the amount of reused bottles should be an integer. A negative one is not available for the scenario.
Table 7,
Table 8,
Table 9,
Table 10 and
Table 11 illustrate the analysis results for each scenario. The bigger the absolute value of the variation, the more influence the variable changing in the scenario brings.
Table 7 shows the results of the scenario of changing the recycling rate. The variation range of the three bottles is ±1.92%, ±4.79%, and ±0.93%, respectively. Changing the recycling rate has the greatest influence on No. 2.
Table 8 shows the results of the scenario of changing material use in manufacture. The variation range of three bottles are ±9.48%, ±8.46%, and ±4.64%, respectively. Changing material use has the greatest influence on No. 1 and a slightly lower influence on No. 2.
Table 9 shows the results of the scenario of changing product usage amount. The scenario simulates two types of user behaviour, over-use, and appropriate use; it is assumed that using 80% and 90% of the product has the same effect on the user as using 100%, and over-use behaviour has no better performance to the user. The variation ranges of the three bottles are ±20% equally.
Table 10 shows the results of the scenario of changing transportation distance. The variation ranges of the three bottles are ±0.66%, ±1.52%, and ±0.33%, respectively. Changing transportation distance has the greatest influence on No. 2.
It is assumed that 10% and 20% of bottles are reused directly by the user for the last scenario. Therefore, the amount of tap water used for cleaning after being used up is increased by 10% and 20% respectively. The environmental impact is shared on the reused bottle, which becomes 90.91% (100%/110%) and 83.33% (100%/120%).
Table 11 shows the results of the scenario considering direct reuse by the user. The variation range of three bottles is from 0 to −16.67%.
According to the variation range of the scenarios, the significance of these variables to the sustainable design of these bottles is obtained, as
Table 12 shows.
5. Conclusions
This research conducts a set of LCA of cosmetics packaging to determine to what extent do these scenarios, including material selection or reduction, over-use or appropriate use, increasing recycling rate, reducing transportation distance, and increasing direct reuse, influence the environmental performance of the packaging. The practical significance is that the designer can conduct a streamlined LCA during the evaluation stage of concept design, using primary data of previous generation products from a cooperative manufacturer, or secondary data from relevant industry databases with sensitivity analysis. In this case, the LCA results will indicate which design concept performs better for the environment, reveal the priority and importance of these design variables, and guide designers to improve the environmental performance of the product at the very beginning. In addition, it emphasises that the designer not only has the right to determine structure and appearance, to select material and manufacturing process, but also has the power to influence recycling, reuse, and appropriate use behaviours of the user. The sustainable design approach becomes more plentiful and diversified.
Based on the results of the LCIA and the sensitivity analysis, sustainable design strategies and corresponding potential schemes of cosmetic packaging are proposed as follows in descending order of significance from the aspect of facilitating user reuse and recycling behaviour, material selection, and others.
To select PET rather than glass if the cosmetic product has no specific protection requirement.
To reduce the usage amount of the product under the premise of ensuring the designated use effect.
Design for appropriate use, mensurable and adjustable dispenser.
Instruction for appropriate use, universal graphic instruction for improved recognisability and readability, visual guidance of use effect, use efficiency self-assessment.
To advertise rational purchase and consumption.
To increase the direct reuse by the user.
Design for easy cleaning and reuse.
Design for long service life.
Providing refill packaging.
Straightforward graphic instruction for reuse and visible benefit advertising.
To reduce material use in manufacture.
More reasonable and responsible structure and function design.
The emerging technology of manufacture.
Recycling material is preferred.
To increase the recycling rate of packaging materials.
Design for disassembly and recycling.
Instruction and universal graphic design for proper recycling.
Recycling oriented material selection.
To reduce the transportation distance of the packaging.
Furthermore, this research is based on a set of assumptions and has some limitations. The following works need to be studied in the future to reinforce the research outcome.
Primary data acquisition of manufacturing and waste scenario in China.
Design for reuse and recycling, and user behaviour research.
Appropriate use and use effect research.