Goodbye Plastic Bags? Lessons from the Shopping Plastic Bag Ban in Chile

Round 1

Reviewer 1 Report

This manuscript explores the intriguing topic of the plastic bag shopping ban in Chile, presenting insightful findings on its impacts and outcomes. It is a beneficial article. However, some suggestions have been made for minor revisions to improve the article.

- Check the citation format on page 10, line 330
- The decimal point should be written following international standards on the y-axis of Figure 3 and in other parts of the content.
- The conclusion should be more concise.

This is good and easy-to-read English writing.

Author Response

Thank you for your comments and suggestions. Below, we comment on each one:

The format of the citation on page 10, line 330 has been corrected.

A review of the use of english was carried out and text, graphs and tables were adapted to the international format for the decimal point.

We consider the conclusion to be as consistent as possible, so we decided to keep it in its original version.

Finally, we would like to mention some changes that we incorporated into the document given comments from other reviewers:

• We have added a paragraph in the introduction mentioning some of the impacts of SUPBs on human and ecosystem health.
• Mention was made of who were the main producers and importers during the study period.
• We move one of the graphics to the main body (share of net imports).
• New reflections were added in the discussion section, incorporating the explicit mention of international cases (previously they were mentioned only in aggregate form)
• A sub-section was included with public policy recommendations that emerge from the case study.
• An annex is added with the detail of the main plastic bags in Chile.

Note that the changes are marked with the track changes tool in word. Except for those changes in formatting, language and the discussion section.

Reviewer 2 Report

The paper provides a comprehensive study of the impact of the Chilean plastic bag ban law. Here are some suggestions for improvement:

1.     In the abstract, provide more specific numerical data or percentages where applicable to quantify the reduction in SUPBs consumption, the increase in bin liners, and the improvement in environmental performance across the eighteen categories studied.

2.     The plastic pollution generated, and health issues associated with its toxicity are relatively important for investigation. In your introduction section, add a paragraph that describes the genesis of toxicity from plastic wastes and links the situations with their implications for human health.

3.     Additionally, on page 1, within paragraph 1 (line 19-30): the specific types of toxins from plastic pollution need to be mentioned. Instead, add this “Recent studies have demonstrated that degraded plastic releases a wide range of toxic chemicals, including plasticizers, flame retardants, and colorants, which have the potential to leach into the environment, thereby contaminating soil, water, and air.” Kindly include this reference to back up the data you claimed 10.1016/j.enconman.2022.115758.

4.     In the results and discussion section, it is recommended that the author should provide a greater depth of discussion about each result and not just an interpretation of what is shown in the figure. Additionally, improve the paragraphs by elaborating more with comparative interpretation of empirical results and linking it with broader and deeper literature.

5.     Comparing the research findings with previous studies from both Chile and other places is valuable. It helps to contextualize the results and assess the significance of the plastic concentrations found in the country. Additionally, it's important to link these findings to potential sources or origins of the plastics, as suggested. This adds depth to the analysis.

6.     It would be more interesting if the authors focused more on the significance of their findings regarding the importance of the interrelationship between the obtained results and sustainable development/cleaner production in the sector context, and the barriers of doing it, what would be the consequences, in the real world, in changing the observed situation, what would be the ways, in the real world, to change/improve the observed situation.

7.     What are the practical and policy implications of this study? Also, discuss and explain the appropriate regulatory policies should be based on your research findings. It is strongly recommended to add this as a sub-section, before the conclusion.

8.     Unfortunately, a lot of valuable data was shifted to the appendix. I would like to encourage the authors to add them to the main manuscript and discuss their result trends. 

Author Response

Thank you for your comments and suggestions. Below, we comment on each one:

We have added a paragraph in the introduction mentioning some of the impacts of SUPBs on human and ecosystem health (including the recommended article). We are aware that these impacts can vary greatly between types of plastics, manufacturing processes and the waste management contexts of each country. For this reason, we prefer to mention the high-level repercussions and not go into further details.

In our opinion, the results section should show the results found in the study without the authors' judgments, while the discussion section should provide more depth in the discussion.

Given the reviewers' comments, it was decided to explicitly mention what has happened in other cases of plastic bag bans around the world (previously they were mentioned only in aggregate form) and to add reflections on the possible causes of the results given the Chilean context. In addition, a sub-section was included with public policy recommendations that emerge from the case study.

However, linking these findings to potential sources or origins of the plastics is beyond the scope of this study. Especially considering that plastic bags represent only a small fraction of the total plastic in our ecosystems.

We appreciate the interest in the information in the annexes and we decided to move one of the graphics to the main body (share of net imports). We hope this will contribute to the discussion of future studies.

Finally, we would like to mention some changes that we incorporated into the document given comments from other reviewers:

• Mention was made of who were the main producers and importers during the study period.
• An annex is added with the detail of the main plastic bags in Chile.

Note that the changes are marked with the track changes tool in word. Except for those changes in formatting, language and the discussion section.

Reviewer 3 Report

Maximiliano et. Luis evaluated the bans on single-use plastic consumer bags with regard to the fact that such was based on reduced SUPBs consumption and the impacts of substitutes were ignored.

The work fills one of the problems' void by examining the legislation banning plastic bags in Chile, indicating a decrease of approximately 249 kilotons in the consumption of single-use plastic bags (SUPBs) and a shift towards alternative materials, primarily paper. The work also states a notable increase of over 50% in the use of bin liners following the implementation of the ban. Despite some unintended consequences, there's an enhancement in the environmental impact of the bag market across fifteen out of the eighteen categories analyzed.

The work is of value and current interest but requires improvements.
Some critical aspects require revision, these are:

Line 33: "is the ban of a product" state and cite the reasons why.
Also state the efforts of civic movements and NGOs actions that demanded such legislative changes.

2.1. Background information

Polymer type used in Chile plastic bags is not stated, such information is a must.

3.2.1. Bags produced in Chile
Plastic bags

Who are the main producers of Chile polymer bags?

3.2.2. Net imports of bags

Who are the main producers of the imported polymer bags?

3.3. Unit environmental impacts for type of bag.
Plastic is not just plastic, i.e. a PP marked plastic bags contains a lot more than just polypropylene, in example a great number of additives, however due to the very permissive legislation regarding the plastic industry and production such are not stated next to the polymer type symbol. As this is an scientific release investigating the plastic bags issues, it should be stated by the authors which additives are used in Chile produced plastic bags, and/or the imported ones. Such information would greatly improve the overall quality of the work and could result in a higher citation rate as plastic bags are one of the main pollutants in both soils and in aquatic environments.

Author Response

Thank you for your comments and suggestions. Below, we comment on each one:

The main reasons why banning the product is one of the most widely used public policies were included. However, detail the efforts of civic movements and NGOs actions that demanded such legislative changes is outside the scope of this article. In fact, what prompted the creation of the ban in Chile is very well detailed in the article of Amenabar et al. (2020)- https://doi.org/10.1016/j.ocecoaman.2019.105079

The polymer used in Chile in the plastic bags is detailed in the methodology.

Mention was made of who were the main producers and importers during the study period. Unfortunately, with the available data it is not possible to determine who are the main producers of imported polymer bags.

Regarding the other components that plastic bags may contain, there is too great a diversity in the market to describe them. However, an annex is added with the detail of the main plastic bags in Chile. We hope it will be useful for the community.

Finally, we would like to mention some changes that we incorporated into the document given comments from other reviewers:

• We have added a paragraph in the introduction mentioning some of the impacts of SUPBs on human and ecosystem health.
• We move one of the graphics to the main body (share of net imports).
• New reflections were added in the discussion section, incorporating the explicit mention of international cases (previously they were mentioned only in aggregate form)
• A sub-section was included with public policy recommendations that emerge from the case study.

Note that the changes are marked with the track changes tool in word. Except for those changes in formatting, language and the discussion section.

Round 2

Reviewer 2 Report

The manuscript has successfully addressed all reviewer comments, and I recommend accepting it for publication.

Reviewer 3 Report

I have no further comments. The revision significantly improved the quality of the manuscript. Accept in current state.