Toxic Study on the New Eco-Friendly Insulating Gas Trifluoromethanesulfonyl Fluoride: A Substitute for SF₆

Round 1

Reviewer 1 Report

This paper proposes, "Toxic study on the new Eco-friendly insulating gas trifluoro-methanesulfonyl fluoride: a substitute to SF6”, the idea and proposed work is very interesting. I would like to suggest few comments :

• Authors must include a section or subsection to show the core contribution of their proposed work.
• A discussion on the possible limitations of their work may be included to enhance the quality and ethical fairness of their work.
• Some typo and grammar mistakes must be removed as well.
• The current paper requires moderate English proof read.

Author Response

Reviewer #1:

This paper proposes, "Toxic study on the new Eco-friendly insulating gas trifluoro-methanesulfonyl fluoride: a substitute to SF6”, the idea and proposed work is very interesting. I would like to suggest few comments :

Question: Authors must include a section or subsection to show the core contribution of their proposed work.

Response: The related description was added in the last paragraph in Section 1. Introduction.

Question: A discussion on the possible limitations of their work may be included to enhance the quality and ethical fairness of their work.

Response: The addition was shown in the third paragraph in Section 2.2. Test method.

Question: Some typo and grammar mistakes must be removed as well.

Response: Authors checked all sentences and words. In additions the paper was editing by MDPI language service.

Question: The current paper requires moderate English proof read.

Response: The authors reorganize related sentences and modify related statements. The paper was also editing by MDPI language service (English Editing Articles ID-43157).

Reviewer 2 Report

1. In Table 1, the mark/word on the molecular strcuture is too obscure, please re-plot them.
2. In Figure 1, the red wavy line under the word "Flowmeter" should be deleted.
3. The outlook should also be provided in the end of the manuscript, to provide a better understanding.
4. I would like to suggest going through the manuscript more carefully for clarity, syntax and correctness. The English should be improved for the sake of clarity.

Author Response

Reviewer #2:

Question: In Table 1, the mark/word on the molecular strcuture is too obscure, please re-plot them.

Response: The element mark was revise to be more clear.

Question: In Figure 1, the red wavy line under the word "Flowmeter" should be deleted.

Response: We are very sorry for our negligence of this figure. The mistake in Figure 1 has been revised.

Question: The outlook should also be provided in the end of the manuscript, to provide a better understanding.

Response: We have re-written this part according to the Reviewer's suggestion. The description about outlook and mean was provided in the end of this manuscript.

Question: I would like to suggest going through the manuscript more carefully for clarity, syntax and correctness. The English should be improved for the sake of clarity.

Response: The authors reorganize related sentences and modify related statements. The paper was also editing by MDPI language service (English Editing Articles ID-43157).

Reviewer 3 Report

The article contains new data and is devoted to topical issues.

The authors conducted a toxicity study insulating gas trifluoro-2 methanesulfonyl fluoride. This gas is an environmentally friendly replacement for the widely used SF6 gas in high voltage electrical equipment. The authors used the Horn's method on rats.

 

The article need a revision:

 

1. The authors did not indicate the reasons for the choice of concentrations (1473 ppm, 3166 ppm, 6834 ppm and 14727 ppm) and the time of the test (4 hours). Is it somehow related to the concentration or the time of contact with the gas source in the workplace?

2. There is some contradiction in the conclusions. The first one states "The gas was not found to cause continuous or lasting harm to the rats", the second lists the affected organs, which includes the heart, lungs, spleen and eyes.

Author Response

Reviewer #3:

The article contains new data and is devoted to topical issues.

The authors conducted a toxicity study insulating gas trifluoro-2 methanesulfonyl fluoride. This gas is an environmentally friendly replacement for the widely used SF6 gas in high voltage electrical equipment. The authors used the Horn's method on rats.

The article need a revision:

Question: The authors did not indicate the reasons for the choice of concentrations (1473 ppm, 3166 ppm, 6834 ppm and 14727 ppm) and the time of the test (4 hours). Is it somehow related to the concentration or the time of contact with the gas source in the workplace?

Response: These test values were according to Chemical Toxicological Evaluation Procedures and Test Methods (GBZ/T240.4-2011) Part 6.2 Dose Design and Horns’ method. It was shown in 2.3. Test method.

Question: There is some contradiction in the conclusions. The first one states "The gas was not found to cause continuous or lasting harm to the rats", the second lists the affected organs, which includes the heart, lungs, spleen and eyes.

Response: "The gas was not found to cause continuous or lasting harm to the rats" means that the rat who was not died in the process were still live and not show other harms in future. The affected organs mainly were resulted from the rat who was died in the process in test.

Reviewer 4 Report

Dear authors,

Find the comments and suggestions that came up for your work. All these should be addressed before supporting the publication

Major

1. The authors are encouraging to support this statement “The concentration could be stable in test owing to good air tightness of chamber” with evidences. What about leakage, filtration test, or opening/closing step?
2. The authors comment throughout the manuscript that they have not considered certain studies, cases, variables, or that in their previous work, etc; I recommend removing all these paragraphs as it shows the lack of novelty and importance of the work.
3. Provide a Discussion section. The Authors limit themselves to describing what was observed.
4. It is not entirely clear how the 4 hours was selected as the test time. In your study, is there a correlation between exposure time and gas concentration?
5. Figures 5-8 must be labeled as a, b, and c (with the corresponding parameter analyzed) to be discussed properly.  

Minor

1. Change the keyword “new Eco-friendly insulating gas” to a short one
2. At the beginning of the intro part, use the abbreviations between parenthesis: GCB (generator circuit-breaker) by generator circuit-breaker (GCB), etc
3. Reference missing: “Total production of SF6 in China was estimated to be 7000 tons/year and still increasing” [?]
4. What about the bioethical concern using rats?
5. Improve Figure 1. Flowmeter word is underlined in red
6. No reference found: Our previous work proved that a mixture of CF3SO2F/CO2 or CF3SO2F/N2 obtained satisfactory electrical performance and liquefaction when the CF3SO2F gas pro-138 portion was approximately 40~50%. [?]
7. Concentration units appears as g/m3, these ones must be corrected as superscript throughout the text
8. In test method: The molar concentrations are given between parentheses and written again one line latter.
9. Create a subsection to describe all equipment used for the analysis and characterization
10. Give a short description of Figure 4a in the main text

Author Response

Reviewer #4:

Dear authors,

Find the comments and suggestions that came up for your work. All these should be addressed before supporting the publication

Major

Question: The authors are encouraging to support this statement “The concentration could be stable in test owing to good air tightness of chamber” with evidences. What about leakage, filtration test, or opening/closing step?

Response: “The volume of the test gas was relatively lower than the total volume of the 300 L chamber. Therefore, the change in gas pressure could be ignored. The outward gas valve was always closed when the gas was added to the chamber by another valve. It was closed until the concentration in the chamber reached the intended value, which could be found by the flowmeter and gas purified machine if the leakage situation appeared in the test.” The related description was shown in 2.1. Acute toxic gas inhalation test device.

Question: The authors comment throughout the manuscript that they have not considered certain studies, cases, variables, or that in their previous work, etc; I recommend removing all these paragraphs as it shows the lack of novelty and importance of the work.

Response: The related description was revised.

Question: Provide a Discussion section. The Authors limit themselves to describing what was observed.

Response: We have re-written this part according to the Reviewer's suggestion. Actually the section 3.3 contained discussion. Authors also added some individual insights into this section and a new title was added and revised.

Question: It is not entirely clear how the 4 hours was selected as the test time. In your study, is there a correlation between exposure time and gas concentration?

Response: The test time was selected owing to Chemical Toxicological Evaluation Procedures and Test Methods (GBZ/T240.4-2011) Part 6.2 Dose Design. The maximum dose method was adopted, that is, a certain number of rats were inhaled with the specified concentration of gas for 4h. If no death appear the acute inhalation toxicity test of multiple doses would not be carried out.

Question: Figures 5-8 must be labeled as a, b, and c (with the corresponding parameter analyzed) to be discussed properly.  

Response: The labels in Figures 5-8 were added. The related descriptions after these figures were also revised.

Minor

Question: Change the keyword “new Eco-friendly insulating gas” to a short one

Response: The keyword “new Eco-friendly insulating gas” was revised to “insulating gas”.

Question: At the beginning of the intro part, use the abbreviations between parenthesis: GCB (generator circuit-breaker) by generator circuit-breaker (GCB), etc

Response: Some abbreviations have been deleted because they only appeared once in this paper. Other abbreviation such as GWP has been revised.

Question: Reference missing: “Total production of SF6 in China was estimated to be 7000 tons/year and still increasing” [?]

Response:  The description was not corrective. “Total production” should mean whole world. It has been revised. The related reference was “Levin I, Naegler T, Heinz R, et al. The Global SF6 Source Inferred from Long-term High Precision Atmospheric Measurements and Its Comparison with Emission Inventories[J]. Atmos. Chem. Phys., 2010, 10(6): 2655-2662.”. It has been added.

Question: What about the bioethical concern using rats?

Response: All parts of this experiment completed in the Food and Drug Safety Evaluation Center of Hubei Center for Disease Control and Prevention would comply with the experimental protocol and amendments and the Standard operating procedures (SOP) of the Center. Experimental protocols and amendments or procedures involving the management and use of animals have been approved by the Animal Management and Use Committee of Hubei Center for Disease Control and Prevention prior to commencement. The license number of laboratory animal was SYXK 2017-0065. Experimental animal quality certificate No.42000600038239 and No.42000600038360. The description was added into related paragraph.

Question: Improve Figure 1. Flowmeter word is underlined in red

Response: We are very sorry for our negligence of this figure. The mistake in Figure 1 has been revised.

Question: No reference found: Our previous work proved that a mixture of CF3SO2F/CO2 or CF3SO2F/N2 obtained satisfactory electrical performance and liquefaction when the CF3SO2F gas pro-138 portion was approximately 40~50%. [?]

Response: The reference “Wang Y, Sun M, Gao Z, et al. Synthesis and Dielectric Properties of Trifluoromethanesulfonyl Fluoride: An Alternative Gas to SF6[J]. Industrial Engineering Chemistry Research, 2019, 58(48):21913-21920” was added.

Question: Concentration units appears as g/m3, these ones must be corrected as superscript throughout the text

Response: All superscripts and subscripts have been revised included concentration units.

Question: In test method: The molar concentrations are given between parentheses and written again one line latter.

Response: The molar concentrations followed corrective unit have been revised.

Question: Create a subsection to describe all equipment used for the analysis and characterization

Response: Section 2.2. Analysis equipment was added. It included the information of all equipment.

Question: Give a short description of Figure 4a in the main text

Response: The description of rats’ behavior about Figure 4a was added.

In additions, special thanks to you for your good comments.

Round 2

Reviewer 2 Report

Accept

Author Response

Thank you for your suggestions again.

Reviewer 4 Report

Dear Authors, thank you for considering all the criticisms point by point.

 

 

Author Response

Thank you for your suggestions again.