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Appendix C

Charge to Peer Reviewers

Cleaner Technologies
Substitutes Assessment for Fabricare:
Including Wet and Dry Cleaning Technologies


July 1997


TECHNICAL PEER REVIEW: Cleaner Technologies Substitutes Assessment (CTSA) for Fabricare: Including Dry and Wetcleaning Technologies

Charge to CTSA Peer Reviewers

The following is intended to provide structure for your review and to enable the EPA to address your comments directly in the final revision of the CTSA.

The CTSA document is intended to provide a flexible format for systematically comparing the technical and economic tradeoff issues associated with traditional and alternate products, processes, and technologies. The goal of the CTSA is to offer a detailed picture of the environmental impacts, cost and performance issues associated with each option to assist users to make informed decisions about which alternatives are best for a particular situation. The CTSA document is not intended to resolve all uncertainties in data cited nor in methodology employed. For example, this document is not intended to resolve the controversy on the carcinogenic potential of perchloroethylene, nor on the appropriate slope factor. These issues have been extensively debated by the scientific community. Rather, the document is intended to demonstrate a sufficient basis for concern, to compare alternative exposure scenarios and to provide alternative approaches in communicating risks. The EPA is seeking comment on the presentations of science, technology and economic considerations in the document. Issues related to policy considerations are beyond the scope of this peer review.

The information contained in the human health hazard sections was gleaned from existing summaries, by the agency, its sister agencies or from professional groups taking positions in accepted published sources, as well as supplemented by primary sources. They do not represent primary research or a position based solely on primary sources. A summary appears in Chapter 2, with more technical presentation in Appendix B.

As you review the document, if you wish to comment or suggest specific changes, please annotate directly in the text where the change or additional work is needed. If the provided space is insufficient, please continue on a separate sheet of paper. After reviewing the document, prepare a summary report that addresses your major issues. Please present your comments constructively, be specific about the issues/changes suggested, and cite the page number where the change should occur. If an issue has been omitted or addressed improperly, please give specific information on how it should be addressed. If you are citing a new reference (that has not been previously provided by the EPA), please provide a copy and indicate where in the text it should be included.

The Office of Pollution, Prevention and Toxics of the EPA has prepared a series of issues and questions relevant to each section and topic area. These items are deemed by EPA as areas of concern to be considered and will aid in guiding your peer review. You may address these issues along with any other concerns in your report. After you have completed your review, please return both the document and your comments, along with a copy of any new reference(s) to the contractor (Battelle).

The CTSA document is an internal, preliminary work product developed by the EPA. Neither the contractor nor the peer reviewers may distribute, cite, quote or in any manner release any portion of the document. All copies of the document, support material, and comments will be returned by Battelle to EPA.


The following are several areas of concern that are applicable to the entire CTSA document. These issues pertain to content, format, and presentation. Are you aware of any enhancements which would improve the general presentation of information pertaining to the following issues.

Chapters 1 through 8

1. Does each of these chapters clearly explain its purpose? If the chapter purpose is not clearly articulated, indicate what you believe the purpose of the chapter was.

2. Is the text clear and well presented? Can you suggest other ways to present the information to enhance its clarity?

3. Do tables/figures enhance understanding of the information presented in these chapters? If not, how should the information be presented? Please provide an example.

4. Are there any inconsistencies between the data presented in the tables and text? Can you suggest other ways to present the information? Please provide an example.

5. Are relevant references provided for the information contained in each of these chapters?


The Economic elements of the CTSA are found in Chapters 1, 6, 7, and 8.

A. Chapter 1, Overview of Drycleaning

1. Does this chapter help set the stage for the comparative evaluation you understand will follow?

2. Are you aware of any specific sources where information is more current or different from that quoted in this chapter?

B. Quantities where we would particularly appreciate your knowledge of newer or higher quality data include:

1. Solvent mileage (solvent use per unit of clothes cleaned), by technology.

2. Maintenance costs for machines in use.

3. Volume of clothes cleaned, by technology.

4. Permitting costs, are these factored in to the trade off issues correctly?

5. Projected demand, by technology.

6a. Average site releases to H2O, each technology, total U.S. releases.

6b. Average site releases to air, each technology, total U.S. releases.


A. Process Descriptions

1. Are the proper primary equipment and operations included? If not, what has been omitted?

2. Do the technologies appear to have been properly categorized? If not, what categorization would be more appropriate?

3. Are the descriptions accurate and adequate?

B. Environmental Release Estimates

1. Are release estimates reasonably accurate, keeping in mind that the relative differences between technologies for a given solvent are the primary purpose for the estimates? If not, please provide enough information, including bases, to calculate new estimates.

2. Are these release estimates adequate to properly distinguish the important differences between the various technologies for each solvent?

3. Have any important equipment or operational factors been omitted? If so, please provide a basis for each new factor, if available, for quantification.

4. Are the assumptions reasonable? If not, please provide a basis for any new assumption.

5. Are the exposure characterizations in Chapters 3 and 4 consistent with one another? Do they help the reader understand the context for evaluating risk?

6. Perc occupational and residential exposures have been measured in a number of disparate settings by various protocols. Do the summarization measures and descriptions adequately convey the variety and the contribution it has to the estimates of exposure and risk in different scenarios? Should anything specifically be added to the text in Chapters 3, 4, and 8?

C. Environmental Release Assessments

1. Are the estimates reasonable? If not, what other estimates could be used? In providing other estimates, please include the basis for each estimate and an example.

2. Are the data sets used for estimations reasonably representative of the industry as a whole? If not, what data would be?

D. Exposure Estimates

1. Are the data sets used for inhalation exposure concentrations or potential dose rates reasonably representative of the industry as a whole? If not, what data would be? Are the data appropriate for the type and magnitude of exposure the EPA is trying to estimate?

2. Is the number of samples taken, in the case of the monitoring studies used in the assessment, statistically significant [although a rigorous statistical analysis was not performed]? If not, how should this be characterized in the text?

3. Are the assumptions reasonable? If not, what assumptions should replace them? Please include a basis to support assumptions.

E. Pollution Prevention, Best Management Practices, and Control Options

1. Are there any other options for operational improvements? If so, what options are omitted? Please provide relevant details.

2. Are there any errors/omissions in process substitutes provided?

3. Are the improvements presented clearly?


1. Is the information presented clearly?

2. Are the exposure scenarios realistic?

3. Have the exposed populations been adequately characterized?


The hazard information for the CTSA is found in Chapters 3 and 4. The health and environmental hazards of Perc, one of the chemicals covered in the CTSA, have been studied extensively. EPA's assessment of the hazards of Perc has been the subject of rigorous peer review, including a review by EPA's Science Advisory Board. The hazards of Perc shall not be a principle focus of this peer review.

A. Chapters 3 and 4, Perchloroethylene and Petroleum Processes, respectively

1. Is the discussion of perchloroethylene dose-response modeling straightforward? Are its sources clear (for readers who want more detail)?

2. Are you aware of human health effects information pertaining to relevant exposures reported on any substance in one of the described technologies that should have been included in the summaries.



The Risk Assessments for the CTSA are found in Chapters 3 and 4 and Appendix G.

A. Chapters 3 and 4, Perchloroethylene and Petroleum Processes, respectively

The Agency is aware that other quantified assessments of perchloroethylene exist, and that there is debate within the scientific community on the interpretation of several metabolic and animal/human extrapolation issues, and these are pointed out in the text. However, the EPA has not updated its earlier dose/response assessment of perchloroethylene, and such a revision is beyond the scope of the CTSA. Also, an updated risk assessment is not considered essential for the purpose of this document, which is to indicate ways users can make decisions about relative risk, and alternative exposure reduction technologies.

1. Does the risk assessment accomplish the objective of highlighting which sorts of situations pose greatest risk of experiencing adverse effects from exposure to each cleaning process? If not, please suggest ways that this objective could be accomplished.

2. Are the effects characterizations in chapter 2 and chapter 4 consistent with one another? Do they help the reader understand the circumstances under which there may be risk?

3. Are the risk tables clear? If not, how might they be improved?

4. Are sources of uncertainty sufficiently covered in the Risk Assessment sections? If not, what other uncertainties should be included?

5. Does the risk assessment for the petroleum solvents clearly convey the fact that there was a disproportionate amount of information, specifically, toxicity information, that was available for most of the cleaning processes in comparison to that available for perchloroethylene? Is there a hidden bias in the assessment that could be corrected with clearer language as to the respective amounts of information we were dealing with?

6. Recently the EPA's Science Policy Council released a final draft (1/6/95) of "Guidance for Risk Characterization." All Agency risk assessments are supposed to adhere to the principles detailed in this guidance document. Do the risk-related sections of the CTSA adhere to the principles discussed in the guidance document? If not, what should be done to improve the CTSA in this regard?

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