Whitmyre Research

2111 Wilson Blvd., Suite 600

Arlington, Virginia 22201

(703) 351-5072

(703) 243-4399 (FAX)

April 4, 2008

Margaret Sheppard

Stratospheric Protection Division

SNAP Program

U.S. Environmental Protection Agency (6205J)

1310 L Street, NW

Washington, DC 20005

RE: Response to USEPA Comments on Outline for White Goods Fault Tree Analysis

Dear Ms. Sheppard:

My thanks to you and your colleagues for taking the time to review the outline for the 

fault tree analysis report relating to use of HCR-188C in white goods. Your comments 

are a good starting point for reaching an understanding of the key issues to discuss in our 

report. To continue the discussion, my responses to your comments are as follows:

(1) Sections VI.C and VII.A to Include Recovery During Disposal.

We agree in principal with this comment and will provide some additional limited text. 

Recovery of HCR-188C from appliances at end of product life will be conducted at 

organized locations by trained technicians. Recovery operations during disposal would 

consist of removal of HCR-188C from appliances using a vampire valve connected to a 

line, and a recovery pump to capture the HCR-188C until the system is empty. During 

recovery, HCR-188C would be pumped into a tank. Once full, the tank would be picked 

up by a recycling company, which would filter the material and re-bottle it for sale as gas 

for barbecue grilles. 

Richard Maruya and I thought it would be helpful to establish boundaries for the disposal 

scenario for the Fault Tree Analysis. We propose that the disposal scenario end once the 

recovered HCR-188C is picked up by the recycler. Therefore, occupational exposures in 

the re-bottling process, transportation risks for the recovered and re-bottled material, and 

residential risk for handling of flammable barbecue grille gas products seem to us to be 

outside of the scope of the Fault Tree Analysis. Similarly, we suggest that disposal and 

recycling considerations for the appliance body beyond the recovery of HCR-188C from 

the spent products are outside of the purview of the Fault Tree Analysis. To include such 

considerations would really encompass a full Life Cycle Analysis, which I don’t think the 

Agency is requesting at this time. Once again, for the purpose of the Fault Tree Analysis, 

we think our area of responsibility for the Fault Tree Analysis should end once the 

recovered HCR-188C leaves the service center or recycling center. Does the Agency

agree with this?
Ms. Margaret Sheppard

Response to USEPA Comments on Outline for White Goods Fault Tree Analysis

April 4, 2008

Page 2

(2) Addition of Scenario for Untrained Service Technician. You have 

suggested that we consider adding a scenario for an untrained technician (which would 

affect Sections VI.C, VI.D, VII.A and VII.B). Richard Maruya and I have discussed this, 

and we find that this is a very unlikely scenario, for the following reasons:

- HCR-188C will be listed for use in new refrigerator/freezers, window air 

conditioners, and stand-alone freezers, not in existing appliances.

- Any new appliances that are “dead-on-arrival” (DOA) at customer 

locations would most likely be returned to the store, which would then 

ship the failed appliance to a service center or appliance recycling/disposal 

center. It is unlikely that a major chain (e.g., Best Buy) would attempt a 

DOA repair at a homeowner’s home with untrained technicians.

- The frequency of release of HCR-188C during appliance repair is greatly

reduced by consideration of cost. For low cost appliances such as window

air conditioners, the cost of most repairs done in the US using trained 

technicians could approach the original or depreciated monetary value of 

the appliance. This would result in a preference for replacement of the 

appliance and disposal of the defective unit, rather than repair.

- The HCR-188C guidelines for use, which have been developed at the 

Agency’s request, direct that only trained certified technicians handle it.

- It is unlikely that a service center or appliance recycling center in the US 

would allow an untrained technician to work with, or handle, any product 

that is flammable without proper training. The potential for legal liability

would prevent a service center from employing untrained technicians to 

perform this critical work. Nor would untrained technicians be permitted 

to work with flammable gases because this would violate both OSHA 

rules and general industry standards.

- Importantly, it is unclear whether we could even obtain the required data 

to undertake a Fault Tree Analysis for the untrained technician scenario.

As with any other product, when warning labels and safety guidelines are provided to the 

user, it is up to the individual end user to follow proper procedures. Safe handling is 

more likely to happen if the individual using the product has received proper training. 

This is why we are specifying that HCR-188C be used only by trained technicians. 

Accordingly, we are respectfully requesting that the Agency withdraw their request to 

add an untrained technician scenario to the fault tree analysis (FTA) for white goods. 
Ms. Margaret Sheppard

Response to USEPA Comments on Outline for White Goods Fault Tree Analysis

April 4, 2008

Page 3

(3) Add Other Cases for Window AC. We described 3 different cases as 

examples to be analyzed in the fault tree analysis for window air conditioning units. You 

have asked that we add an additional case wherein the fan is running but the AC mode is 

off. We will include this case in the analysis if we have the necessary supporting data. 

Your conclusion regarding the function of the “vent” we mention for bringing in outside 

air is correct.

(4) Parameter Values in Section VII.D (Consumer Use of Window AC Unit). 

If we find updated parameter values that are more current that those in the 1991 AD Little 

report, we agree to provide references for the sources of the values used in our analysis. 

(5) Comment on Safety Valve Not Needed. Unfortunately, my annotation in 

the outline in Section IX regarding a lack of need for any kind of safety valve was 

inadvertently included. This statement in Section IX, which was more really a note to 

myself rather than a major point, was accidentally carried over from a draft into the 

version you reviewed. This caused some confusion among reviewers of the outline. The 

point that was being made was that such a small amount of HCR-188C is required in 

these appliances (HCR-188C is a “medium-pressure” refrigerant) that a pressure relief 

valve is not necessary because there is virtually no risk of over-pressurization. I suggest 

that we delete this point from the outline, given that it has already caused confusion, and 

not raise this issue in the report, because it is not relevant. Does the Agency agree? My

apologies for any confusion.

(6) Correction of Terminology. Thank you for pointing out our incorrect use 

of the term “registered use”. We will make the correction to “listed use” as you suggest, 

wherever this would have occurred in our report.

I will be providing a signed hardcopy of this letter to you for your files via overnight 

Federal Express delivery. Feel free to contact me at (703) 351-5072 or by email at 

riskscicom@aol.com if you have any questions, or if you would like to further discuss the 

proposed outline.

Best regards,

Gary Whitmyre, D.A.B.T.

CC: Richard Maruya (A.S. Trust)