p.1 

OAR Box 1147 

Prepped by Ollie Stewart 

Document Number: 

208) IV-E-82 

Docket Number: 

A-87-11 

Printed 4/22/2008 2:42:58 PM Sheet 208 of 242 
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P.2 

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Update on EPA's 

Analysis of Onboard Safety , 

November 1988 

System Safety and Security Section 

Battelle Columbus 

and 

U,S, EPA 

Office of Hobile Sources 
P.3 

Overview 

1, Introduction USEPA 

2, Failure Bodes and Effects Analysis Battelle 

3, Service' Station Refueling Risk Assessment Battelle 

., Summary of EPA Safety Study US EPA 

5, Summary of NHTSA Comments on Safety Study US EPA 

6, Ford and GM Comments on Simple USEPA 

Onboard System and EPA Response 
P.4 

Vehicle Fuel System Comparative Risk Assessment: 

Failure Modes and Effects Analysis 

Summary of Analysis and Initial Findings 

Battelle-Columbus 
P.5 

Service Station Refueling Risk Assessment 

Battelle-Columbus 
P.6 

Summary of EPA Safety Study 
P.7 

Assessing the Safety Issue 

Principal safety concern is that increased complexity 

leads to an "unquantifiable" increase in risk 

Revised safety study addresses this concern three ways: 

Shows that complexity does not have to increase risk 

Demonstrates that onboard designs can be simple 

Presents some of the safety benefits of onboard 

controls 

Revised safety study concludes that onboard systems need 

not degrade vehicle safety 
P.8 

Addressing Complexity and Risk 

Evaporative system safety used as a baseline: 

No discernible effect of evaporative systems on 

motor vehicle fire rates 

Minimal problems resulting in safety recalls, 

manufacturer service bulletins, or owner complaints 

(see Table 1) 

No reports of deaths or serious injuries 

Evaporative system safety/complexity: 

Wide variety of complexity in current evaporative 

systems 

Many of the "complex" features proposed for onboard 

control systems were found to already exist in-use 

on numerous fuel/evaporative system designs (e.g., 

multiple vapor lines, fillneck mounted valves, 

plastic components, and liquid/vapor separator tanks) 

None of the available information suggested any one 

design was either more or less safe than another 

For the vehicle systems most like onboard systems we 

found no relationship between complexity and risk 
P.9 

Table 1 

Evaporative System-Related Recalls, 

Service Bulletins, and Owner Complaints 

Total Evap Related 

Safety Recalls (Since 1970) 4200 20 (0.5%) 

Manufacturer Service Bulletins 88000 <120 (O.tt) 

(Since 1970) 

Owner Complaints (Since 1977) 210000 <100 (0.05%) 
P.10 

Development of a Simple Onboard System 

Designs suggested by manufacturers more complex than those 

anticipated by the Agency 

EPA has always anticipated onboard control would require 

relatively simple designs and undertook a development 

program to design a simple system and address 

manufacturers' concerns over complexity 

Two design constraints established: 

Simple system should incorporate the fewest features 

possible u perform the necessary functions 

Simple system should be based on current production 

hardware 

EPA successfully built and tested an onboard system no 

more complex than the original' evaporative system 

Onboard systems need not be as complex as suggested by the 

manufacturers 
P.11 

Net Safety Impact of Onboard 

Design improvements: 

Lower fuel tank pressures - reduces fuel spurting 

Control of non-FTP evaporative emissions 

Simplified design features - no need to increase 

complexity 

Service station safety: 

Refueling vapors currently vented to a potentially 

hazardous location will instead be routed to a 

charcoal canister 

Decreased fuel spillage due to test procedure 

requirements 

Onboard systems should have no negative effect on vehicle 

safety - opportunities to improve safety 
P.12 

Summary of NHTSA Comments on 

EPA Safety Study 
P.13 

Background 

Section 202 (a)(6) of the Clean Air Act requires that EPA 

consult with DOT regarding the safety implications of 

onboard control systems. 

Consultation process has been underway for about 2 years. 

Numerous meetings, discussions held and analysis/comment 

shared. 

During these previous consultations, NHTSA expressed 

concern that onboard systems will add complexity and 

increase the opportunity for crash and non-crash fires. 

As part of this consultation process, draft EPA safety 

study was submitted to NHTSA for comment in early August 

with comments received back in late October. 

During this time period ITS A briefed by GM and Ford on 

their experience with the simple onboard system, and NHTSA 

also evaluated a vehicle equipped with a prototype onboard 

system developed by API. 
P.14 

Summary of Key NHTSA Comments 

All safety concerns not yet satisfactorily addressed. 

Further engineering demonstration and/or testing needed to 

assure onboard controls will not result in a safety 

problem. Urged EPA to continue to monitor system 

development and address manufacturer concerns. 

Agreed that there have been few problems with evaporative 

system safety and that simple onboard systems and current 

evaporative systems are physically and structurally 

similar. 

However concern expressed over "functional complexity" of 

fuel systems with onboard controls versus only evaporative 

controls, especially safety effects in the areas of 

finability, and driveability. These concerns now 

overshadow their complexity concerns. 

NHTSA emphasized that sufficient leadtime is critical to 

minimize risks. 
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P.16 

GM/Ford Comments on Simple 

Onboard System and EPA Response 
P.17 

Background 

Possible onboard system designs submitted by manufacturers 

as part of comments on the NPRM were more complex than 

envisioned as necessary by EPA. 

In response, EPA developed and tested a simplified onboard 

approach which integrated refueling and evaporative 

controls into one system. 

EPA presented the results of this concept development 

project to the industry last April, and encouraged the 

industry to evaluate this approach for use on their 

vehicles in lieu of some of the more complex designs their 

comments suggested. 

Both GM and Ford undertook projects to evaluate these 

concepts and briefed EPA and others on their experience. 

Following the presentations to EPA by GM and Ford, EPA 

entered into further. testing to evaluate the concerns 

raised by these manufacturers. 
P.18 

GM Evaluation of EPA Concept 

GM Position 

0 GM built and evaluated its version of the EPA system. 

Installed it on 2 GM A-body vehicles. 

0 GM found that the simple onboard system provided the 

control needed to meet the proposed refueling emission 

standard. 

0 This system performed poorly for GM 

Fill quality was poor 

Liquid carry over to canister 

Loss of control for partial fills 

High running loss generation rate 

0 GM concluded that this system was unsafe and unacceptable 

as a production system. 
P.19 

EPA Response 

0 GM briefed EPA on its results on September 16. 

0 Despite our prior requests, GM presented inadequate detail 

to fully understand its system. 

0 GM's system appears to be significantly different from 

ours. 

EPA system has very high quality fill - better than 

stock. 

EPA valves have been slosh tested and do not allow 

liquid carryover. Valve used by GM had not been 

designed for rollover (and slosh) protection. In 

any event, stock liquid-vappr separators are 

available. 

Our system works well for partial fills. 
P.20 

EPA Response continued 

0 GM has never explained why its system doesn't work and 

EPA's does. 

0 GM has declined to provide its hardware to EPA for 

evaluation. 

0 Increased vapor generation rate is not a significant issue. 

Compared to stock, emissions for unpressurized tank 

were about doubled in GM tests. 

To suppress vapors as it did, GM had to 

significantly increase pressure over stock tank. 

We think this approach would raise substantial 

safety questions. 

Modeling by Ford shows that, with 9 RVP fuel, vapor 

generation with unpressurized tank is only 9*0 

greater than stock. 

Assuming volatility control, we think vapors can be 

controlled without high pressure tanks. 
P.21 

Ford Evaluation of EPA Concept 

Ford Position 

0 Ford also built its own version of the EPA concept and 

evaluated it on a Taurus and on F-250 light-duty truck. 

0 Ford found that the simple onboard system provided the 

control needed to meet the proposed refueling emission 

standard, but at lower flow rates. 

0 Ford's system performed poorly. 

Fill quality was unacceptable 

Vehicle would not fill at high dispensing rates 

Liquid carryover into vent lines. 

Inadequate rollover protection. 

0 Ford concluded that the EPA approach was unsafe and not 

readily adaptable to production vehicles 
P.22 

EPA Response 

0 Ford briefed EPA on Sept 26, 1988. 

0 In response, EPA undertook its own evaluation. 

0 By mid-October we had a fully functioning Taurus fuel tank 

system. 

Used some hardware as for GM work. 

Excellent fill quality and emissions control over 

wide range of test conditions. 

EPA valves have been slosh tested and do not allow 

liquid carryover. Valve used by Ford had not been 

designed for rollover (and slosh) protection. In 

any event, stock liquid-vapor separators are 

available. 

Vent valve was rollover tested in both a special 

testing and on a fuel tank - easily met same 

specifications as current stock valves (video tape 

available) 

0 Ford has been r.able to explain why its system doesn't 

work and EPA's ::es, 

0 Ford has declined to provide its hardware to EPA for 

evaluation.