OAR Box 1818 

Prepped by Ollie Stewart 

Document Number: 

9) ll-C-6 

Docket Number: 

A-87-11 

Printed 11/6/2008 3:12:41 PM Sheet 9 of 79 

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

>«. —^cf WASHINGTON. D.C. 20460 

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FEB I 2 iS37 

THE ADMINISTRATOR 

Mr. Thomas H. Hanna 

President 

Motor Vehicle Manufacturers 

Association 

300 New Center Bldg. 

Detroit, MI 48202 

Dear Mr..Hanna: 

Thank you for your letter of December 22 outlining for me 

•cne key safety issues which you feel must be addressed as part 

of the refueling control decision making process. I appreciate 

your concern that these areas receive proper attention, 

relating as they do to issues of vehicle safety and cost. 

In your letter you identified three main safety concerns: 

fuel system integrity, fuel spitback and fuel dispensing nozzle 

failure. In the first area you described concerns with the 

effect of onboard refueling hardware on the fuel containment 

requirements of Federal Motor Vehicle Safety Standard (FMVSS) 

No. 301. Fuel spitback you describe as a concern about the 

spillage of fuel backed up in the filler neck at the end of a 

refueling operation. As for nozzle failure, this concern 

related to malfunctions of the automatic shutoff mechanism on 

the fuel filler nozzle. 

I agree that each of these areas is deserving of careful 

attention and thorough study. As you know, we have already 

devoted attention to these areas in response to similar 

questions raised in the past. Additionally, as part of our 

coordination process with National Highway Traffic Safety 

Administration (NHTSA) on the safety impacts of onboard 

controls, we are currently involved in supplemental analyses 

addressing several safety matters. These analyses include 

looking at issiues such as those which you raise. 

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The over-all philosophy which we apply to this area is that 

no increase in overall risk should be accepted because of the 

presence of onboard control systems. Nor does this concern 

stop at the demonstration of compliance with FMVSS 301. It 

appears to us that the overall safety impacts for in-use 

vehicles must be evaluated from the broader systems approach, 

recognizing the fact that in-use liability can exist for 

conditions not covered by the Federal standards. 
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Of course, the final choices about exact system designs 

will be with the manufacturers, but we would not adopt a 

program unless it were clear that safe fuel system designs were 

available. At this time we are convinced that this is the 

case. In fact, our analyses indicate that it would be quite 

possible for fuel system safety to improve along with the 

adoption Of onboard controls. One example of how this might 

occur would be through the use of flexible bladders inside the 

fuel tank to contain the liquid fuel and eliminate the presence 

of any fuel vapors. Such containment would improve fuel system 

safety and also eliminate the need for much of the evaporative 

control hardware already on current vehicles. 

There are other aspects of overall fuel system design 

which might be modified at the time of introducing onboard 

controls. Such things as the placement and configuration of 

the fuel tank, the use of side fill versus rear fill fueling 

designs, external versus internal fueling vapor vent lines, 

etc. are all areas of design determined as a result, of 

tradeoffs between competing design goals. We believe that 

current fuel system designs can be improved in such areas as 

these and that the safety of onboard equipped vehicles need not 

be compromised. 

Let me briefly respond to the specific concerns raised in 

your letter. Your first item concerned compliance with FMVSS 

301. Both from our own analysis and from our contacts with 

NHTSA, we believe that compliance with this requirement will be 

relatively straightforward given sufficient leadtime to 

complete the required tests and evaluations. We agree that 

crash related issues must be factored into onboard system 

designs, but we do not find onboard technology to be 

substantially different from current evaporative controls. For 

example, the concern has been raised that the larger onboard 

canister means that a substantially larger amount of fuel 

vapors will have to be carried around on the vehicle. However, 

this will not generally . be the case, since for the great 

majority of the time the onboard canister will not contain any 

more vapors than the current evaporative control canister. 

Refueling vapors will be purged to the engine and burned as 

fuel within a relatively few driving miles following a 

refueling. Similarly, as you indicate in your letter, larger 

vapor lines will, have to be dealt with in some onboard designs, 

but this does; not appear to be an overwhelming engineering 

problem. Over&ll, as described above, we believe that issues 

of total vehicle safety and in-use liability will result in no 

increase in vehicle safety risks, and may even lead to safety 

improvements if safety concerns so dictate. 

Your second concern involved fuel spitback at the end of 

the refueling operation. Because of the requirements of our 

testing procedures for onboard controls, only systems capable 
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of eliminating spitback (which, as you know, occurs on current 

vehicles) will be able to meet any refueling control standard. 

We have had discussions with vehicle manufacturers concerning 

the causes of spitback, and have even been considering the 

possible need for design requirements for dispensing nozzles. 

If onboard requirements were adopted, we would also plan to 

control the dispensing rates for in-use nozzles in order to 

assure the control of spitback. Overall, we would expect the 

incidence of spitback to be less with onboard controls than is 

currently the case, resulting in an improvement in the safety 

issues relative to fuel spitback. 

Finally, you raise the question of the possible failure of 

the automatic shutoff feature on the fuel dispensing nozzle. 

We agree that there must be a mechanism which will alert the 

operator in the event of such a failure without causing a 

dangerous condition to exist. Simple pressure relief designs 

have already been developed which would direct backed up fuel 

out near the filler neck much as happens with current 

vehicles. You suggest that it might be more appropriate to 

implement changes in the fuel nozzle itself. We would be open 

to considering the need for such changes and would welcome more 

information from you about the specific changes involved, and 

their cost in relation to the onboard hardware features 

o.therwise required. 

In closing, I want to thank you for taking the time to 

convey your concerns to EPA. Let me assure you that I am 

committed to the full resolution of all safety issues 

surrounding the use of onboard controls. Your input can be a 

valuable help as we continue with this task. 

Sincerely, 

/ * / 

Lee M. Thomas