p.1 

OAR Box 1142 

Prepped by Ollie Stewart 

Document Number: 

27) IV-H-1 

Docket Number: 

A-87-11 

Printed 4/23/2008 10:21:22 AM Sheet 27 of 30 
or*. ^p 

P.2 

lii~&>/-J£JL 

X £ -H--OI 

|> # m \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

l^l^r / ANN ARBOR. MICHIGAN 48105 

CCD A IQOT OFFICE OF 

O u r H U<J I AIR ANiOn RAniADITIO N 

Dr. Merritt Birky 

National Transportation Safety Board 

Bureau of Technology 

TE-70 

800 Independence Avenue, SW 

Washington, DC 20594 

Dear Dr. Birky: 

Thank you for taking the time to meet with me and my staff 

on September 2, 1987 to discuss the safety issues surrounding 

onboard refueling controls. I recognize the tight schedule you 

are operating under, and trust that we were able to provide 

information which will be useful to you in completing your 

review of this topic. 

As indicated during our meeting, we have been actively 

involved in resolution of the safety questions concerning 

onboard controls and have conducted considerable analysis in 

this area. We believe that the hardware required to implement 

onboard vapor recovery is relatively simple and presents no 

unusual safety challenges. Beyond enlarging the existing 

evaporative control canister and vapor lines, the only hardware 

changes involve a fillneck vapor seal (liquid trap or 

mechanical seal device) and some form of rollover protection 

such as the mechanical shutoff valve on the prototype hardware 

we showed you. Both NHTSA and manufacturers have concurred 

that the hardware required for onboard controls present no 

inherent safety design problem. (We highlighted the important 

passages in the package of manufacturer and NHTSA comments we 

supplied to you.) The main concern which remains is the 

determination of adequate leadtime to allow careful 

consideration of safety factors in onboard system development. 

This is a factor to which, as we indicated to you, we intend to 

give careful consideration in developing our final rules. 

As we emphasized to you at our\meeting, we also believe 

that a full assessment of the safety impacts of onboard 

controls must look at the improvements in general fuel system 

safety which will accompany the new hardware. Our analysis 

indicates that safety improvements will occur in at least five 

areas. There will be a reduction in fuel spillage during 

refueling operations due to our test procedure requirements and 

in-use dispensing rate restrictions. There will be a reduced 

probability of hazard from uncontrolled vapors escaping from 
P.3 

-2-

the canister compared to current evaporative controls, due to 

the increased size of the refueling canister. The removal of 

the refueling vapors from the fillneck exit will reduce the 

potential safety and health hazard associated with those 

vapors. The inclusion of refueling controls will provide the 

opportunity to incorporate safety improvements to other 

existing fuel system components as well. Finally, the proposed 

reduction of fuel volatility will provide overall safety 

enhancements for the fuel system. 

We also discussed the fact that both EPA and NHTSA 

standards are performance based rather than design based. This 

means that manufacturers have flexibility in their design 

approaches to meeting standards, and might take approaches 

which are different than we would anticipate. However, 

provisions of both the Clean Air Act and our regulations 

recognize this possibility and require that manufacturers take 

responsibility for developing safe designs. Section 

202(a)(4)(A) of the Act prohibits the use of unsafe devices by 

manufacturers. According to that Section "no emission control 

device, system, or element of design shall be used in a new 

motor vehicle or new motor vehicle engine for purposes of 

complying with standards prescribed under this subsection if 

such device, system, or element of design will cause or 

contribute to an unreasonable risk to public health, welfare, 

or safety in its operation or function." This requirement is 

reflected in Section 86.084-5(b) (1) of our regulations, as 

contained in the Code of Federal Regulations, which states that 

any system installed to enable a vehicle or engine to conform 

to emission standards "shall not in its operation, function, or 

malfunction result in any unsafe condition ..endangering the 

motor vehicle, its occupants, or persons or property in close 

proximity to the vehicle." We intend to make full use of this 

authority in reviewing any designs eventually submitted to EPA 

for certification under an onboard refueling control 

requirement. We also expect to seek NHTSA review of hardware 

designs before certifying them for introduction into commerce. 

I realize that we have given you a large amount of data 

and analyses to digest in a short time. In our presentation to 

you we attempted to highlight key matters which we believe need 

to be considered. If you have any remaining unresolved 

questions or concerns please do not hesitate to contact me 

again. We enjoyed meeting with you and would be happy to 

provide further information if it would be helpful. 

/ Sincere, 

Chester J. fr$hce, Chief 

Standards Development7and Support Branch 

cc: C. Gray 

•R. Wilson 

Docket A-87-11