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OAR Box 1830 

Prepped by Ollie Stewart 

Document Number: 

24) IV-B-20 

Docket Number: 

A-87-11 

Printed 11/13/2008 7:20:52 AM Sheet 24 of 232 
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A-V7~lj 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

ANN ARBOR MICHIGAN 48105 / V "[5~~7_(_3 

NOV 3 0 1990 

MEMORANDUM 

AUG - I 1991 

OFFICE OF 

AIR AND RADIATION 

SUBJECT: Evaporative Canister Vapor Fires Following NHTSA 

Crash Impact Tests 

FROM: Charles L. Gray Jr., Director 

Emission Control Technology Division 

ORIGINAL _"-N£D BY 

CHARLES L GHAr JR 

TO: Richard D. Wilson, Director 

Office of Mobile Sources 

In March and April of this year, Calspan Corporation 

conducted 35 mph frontal barrier impact tests for the 

National Highway Traffic Safety Administration on a 1990 

Chrysler Lebaron Convertible and a 1990 Chrysler Impen 

After impact occurred on each vehicle, a large, but brief, 

flash of flame was witnessed. This flame was produced by the 

ignition of vapor released from an undetermined amount of 

activated charcoal which had fallen from the evaporative 

canister onto lighting used to film the test. NHTSA 

investigated the tests after it was learned that the 

canisters were placed in an uncommon position (in the front 

wheel well) on these particular Chrysler vehicles. A 

conversation with Vince Quarles of NHTSA on November 9, 1990 

revealed the following details concerning their investigation 

of the incidents: 

• Canister Location. Due to the location of the canister 

in the front wheel well, the canister was completely 

crushed on impact, allowing a large amount of the 

activated charcoal to fall to the ground. The exac: 

amount of charcoal released from the ruptured canister 

was not determined, since the NHTSA investigation was 

not initiated until some time (unknown) had passed after 

the test was performed. EPA has determined from 

certification records that both vehicles use 1.35 liter 

canisters holding 343 g of activated charcoal with 

design working vapor capacities of 50 g. 
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• ;Open Lighting. The charcoal fell onto open lighting used 

by Calspan Corporation to film the test from underneath 

the vehicle. This lighting had only minimal shielding 

and the filaments were exposed to the outside air. 

NHTSA found in its investigation that Calspan was the 

only NHTSA contractor using open lighting to film its 

crash tests and has subsequently directed Calspan to use 

covered lighting in the future. 

• L_j_a_ Filament. Temperatures. Thermocouples, used by 

NHTSA in its investigation of the incident, revealed 

that the temperature in the near vicinity of the the 

filaments is between 1500 and 2000 °F. 

• NHTSA's Investigation. The incident did not receive 

much attention from NHTSA until it was learned that the 

canister was located in the front wheel well, an 

uncommon placement. Also, Calspan technicians indicated 

that the fire flashes were not a major problem and that 

fire incidences of a similar nature had occurred before 

in other crash tests, although the flame was less 

dramatic in those cases. 

• NHTSA's Conclusion. The conclusion of the NHTSA 

investigation was that the occurrence was laboratoryspecific and that no in-use problems of this nature are 

expected. This conclusion is based largely on the fact 

that an ignition source under the vehicle is required to 

release and ignite the vapor from the activated 

charcoal. The existence of such an ignition source in 

normal use is highly improbable. Furthermore, other 

Chrysler vehicles with similar canister placement had 

been tested at other facilities with no incidence of 

fire. 

• Recommendations to Chrysler. NHTSA did not recommend 

that Chrysler change the placement of its canisters 

because it was determined that a safety problem did not 

exist. NHTSA is confident that the fire incidences were 

related only to the use of open lighting at Calspan 

Corporation. 

Relevance to Onboard Refueling Vapor Control 

Although NHTSA's initial investigation has determined 

that the placement of evaporative canisters in unprotected 

crush zones, such as the wheel well, does not create a safety 

problem, it is possible that some concern will be raised 

regarding the safe placement of canisters in proposed onboard 

refueling vapor recovery systems. The incidents involving the 

Chrysler vehicles quickly received the attention of NHTSA 
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personnel involved with the onboard safety issues. In fact, 

the entire investigation was turned over to Scott York, who 

has worked extensively in the area of onboard safety over the 

past few years. 

To address any concern regarding canister placement in 

onboard systems, two key observations can be made. First, 

because NHTSA has determined that the existence of an 

ignition source sufficient to ignite vapor from a ruptured 

canister is highly unlikely, a crash-related safety problem 

does hot exist for evaporative canisters. Since the presence 

of an ignition source would be just as improbable for the 

contents of onboard canisters, it would be difficult to 

justify crash-related safety concerns regarding onboard 

canister placement. Second, it must be emphasized that if 

NHTSA ultimately views canister location as a safety issue, 

it is within their authority to establish requirements to 

ensure no in-use problem exists.