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   HYPERLINK "mailto:riskscicom@aol.com"
 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)	

