1 

Underwriters Laboratories Research 

Program on Material Compatibility and Test 

Protocols for E85 Dispensing Equipment 

by 

Kenneth Boyce, P.E. 

Principal Engineer – North America 

Underwriters Laboratories Inc.

December 2007
2 

Abstract 

Fuel blends such as E85 comprised of gasoline and high percentages of ethyl 

alcohol (ethanol) are being deployed in the United States and other countries. 

The unique chemical nature of high-percentage ethanol fuel blends requires 

special consideration with respect to material compatibility. The polar nature of 

ethanol fuel may cause degradation of materials in contact with the fuel. This 

action may have the potential effect of increasing the likelihood of leaks from 

dispensing equipment or increasing the likelihood of other potential hazards. 

While fundamental comparative test methodologies have been developed for 

coupon level test samples, testing processes for dispensing equipment for high 

percentage ethanol fuel blends were not established. Underwriters Laboratories 

Inc. (UL) conducted a research program to define such processes. 

The Need For Research 

E85 is an automotive fuel blend of denatured ethanol and gasoline, nominally 

blended in the ratio of 85/15. E85 may be blended to include ethanol in the range 

of 70% to 90% based on seasonal blends, geographical blends, and quality 

control factors. E85 has been in use in the United States for use with specially 

designed flex fuel vehicles. 

Traditional gasoline fuels, including low percentage ethanol fuel blends typically 

comprised of gasoline with up to 10% ethanol, have been in use for many years; 

products handling these fuels are addressed by established requirements. Highpercentage ethanol fuel blends, with ethanol content above 15%, have different 

characteristics than traditional gasoline fuels. The polar nature of ethanol is 

significantly different from gasoline. Ethanol is significantly more conductive than 

gasoline and may increase electrochemical action. Ethanol’s hygroscopic nature 

increases its propensity to absorb water. These different characteristics may 

result in a corresponding increase in degrading effects of ethanol fuel on 

materials in the fuel line. 

Exposure of metallic parts to high-percentage ethanol fuel blends may result in 

degradation in the form of corrosion of metals, metal platings, or surface 

treatments, stress cracking, embrittlement, or fatigue. Additionally, the effects of 

galvanic interaction must be considered for high-percentage ethanol fuel blends 

such as E85. E85 is approximately a million times more conductive than 

gasoline. When exposed to E85, metals give up electrons, and the fuel serves as 

an electrical conductor. This galvanic interaction may lead to significant 

corrosion at dissimilar metal interfaces. 

Exposure of nonmetallic parts to high-percentage ethanol fuel blends may result 

in degradation in the form of swelling, shrinkage, hardening, cracking, 

permeation, decomposition, solvation, or extraction. In particular, exposure to 
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ethanol may cause significant increases in volume for some materials. Also, 

ethanol may strip strategic components such as plasticizers from nonmetallics. 

These mechanisms of degradation to metallic and nonmetallic materials may in 

turn cause parts formed from these materials to subsequently fail to perform their 

safety function. In the case of dispensers, this could be primarily manifested in 

two ways. Degradation may result in loss of fuel containment, particularly for 

seals. Also, dispensers include parts providing necessary safety functions, to 

stop the flow of fuel under normal use conditions (such as valves) or abnormal 

conditions (such as breakaway couplings). Degradation may result in failure of a 

safety-related component to perform its safety function, which in turn may result 

in the risk of a fire or explosion hazard. 

Figure 1 – Failure Mode Effect Analysis for Ethanol Fuel Dispensers 

In reviewing the available technical information on the topic of material 

compatibility with high-percentage ethanol fuel blends, the technical 

substantiation for potential material responses to fuel exposure was established. 

However, neither specific technical information supporting the compatibility of 

particular materials nor applied scientific protocols to assess the effects of 

degradation on formed parts were available. 
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UL’s objective was to define performance-based protocols that would permit the 

assessment of the safety of dispensing equipment, constructed from a variety of 

materials integrated into a particular design. In order to accomplish this, UL 

made the determination that there was a need to conduct research in order to 

identify appropriate material compatibility assessment protocols and 

requirements for E85 dispensers and dispenser components. The requirements 

would form a basis for assessing material response in the form of equipment 

safety performance. The requirements would address both minimizing the risk 

that exposure to high percentage ethanol fuel blends may ultimately lead to 

leakage of the fuel, and minimizing the risk of degradation that would result in the 

loss of a necessary dispenser safety function. 

Research Overview 

In order to develop foundational technical information for the safety requirements 

for E85 dispensers, the research test program included several elements: 

• Gasket and Seal Testing – A test assessment of gasket and seal materials 

was initiated to gather data about the response of these materials to 

aggressive test fluids and to various conditions of exposure. 

• Conditioning Exposure Testing of Dispensing Equipment – An exposure 

research test program was developed in order to assess response of formed 

parts to high-percentage ethanol fuel blends. This long-term exposure testing 

was performed at elevated temperature with the samples filled with defined 

aggressive test fluids. 

• Safety Performance Testing of Dispensing Equipment - At the conclusion of 

the conditioning exposure, critical performance tests drawn from applicable 

UL standards were performed to assess fuel containment and safety 

performance, as applicable. 

• Analysis of Extracted Test Fluids – Test fluids that had been extracted from 

the conditioning exposure test samples were subjected to analytical tests. 

The analytical tests identified extracted compounds and byproduct 

compounds of corrosion and degradation. The focus of these efforts was 

specifically to review the foreign compounds as they may affect the response 

of the dispensing equipment, and not fuel quality. 

• Harvested Product Assessments – Samples of dispensers and dispenser 

subassemblies that had been in service in the United States and Brazil 

dispensing high-percentage ethanol fuel blends were obtained for evaluation. 

The dispensers and subassemblies were examined and subjected to 

particular relevant testing protocols in accordance with applicable UL 

standards for safety. 
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Test Fluids 

Three seasonal blends of E85 are defined in ASTM D 5798, Standard 

Specification for Fuel Ethanol (Ed75 – Ed85) for Automotive Spark-Ignition 

Engines, published by ASTM International. Other high-percentage ethanol fuel 

blends, such as E20, are being used on a trial basis and considered for future 

use for all vehicles accepting gasoline. 

Fuel blends over the range of ethanol/gasoline content have different properties. 

Ethanol/gasoline blends with higher gasoline content tend to be more degrading 

on nonmetallic materials, while blends with higher ethanol content tend to be 

more degrading on metals. However, both metals and nonmetals may show 

some response along the continuum. Experience from automotive and other 

applications indicates the most degradation tends to occur with blends having 

ethanol in the range of 25% (i.e. E25) and 85% (i.e. E85). 

Potential fuel contaminants include water, salts, acids, and other substances. 

These contaminants may be introduced to the fuel at different points and 

subsequently passed along through the distribution chain, although the fuel 

station level appears to present the highest risk point for fuel contamination. 

Water may be present in storage tanks from sources such as condensation in 

atmospheric tanks, ground or surface water entering tank seals, settling out from 

petroleum products in previous use, and the like. Soluble road salts may also be 

present in surface water runoff and may end up in the fuel. Salt air condensation 

during sea transport or in coastal areas presents an additional risk of 

contamination from chloride compounds. Consideration of the fuel conductivity 

with absorbed water and salts is a key issue. Acids may also be introduced to 

the fuel during the production process, through oxidation of the fuel, or via 

surface water runoff. Using aggressive test fluids that include contaminants was 

identified as an important practical consideration. 

Corrosion inhibitors are sometimes provided in high-percentage ethanol fuel 

blends. When provided, the inhibitors are included in extremely low 

concentrations – on the order of 30 lbs per 1000 barrels – to reduce the effects of 

corrosion on metallic parts in contact with the fuels. A high percentage of the 

E85 fuel produced today may include corrosion inhibitors, however inclusion of 

these inhibitors is not mandatory. The specific inhibitors used are not defined by 

regulations, and their corresponding efficacy is not known. As such, no reliance 

was placed on the effects of corrosion inhibitors in the research test program. 

However, as a part of the gasket and seal program the potential effects of 

inhibitors on these materials was considered. 

Based on these considerations, tests with an E25 fluid and an E85 fluid to assess 

response of materials over the continuum of gasoline/ethanol blends were 

defined. The defined test fluids were identified as CE25a and CE85a for which: 

• The “C” prefix indicates the use of Reference Fuel C as a standardized 

test fluid to represent gasoline; Fuel C is comprised of 50% isooctane and 
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50% toluene as defined in ASTM D 471, Standard Test Method for 

Rubber Property – Affect Of Liquids, published by ASTM International; 

and 

• The “a” suffix indicates use of aggressive ethanol test fluid made through 

the introduction of defined amounts of water, sodium chloride, sulfuric 

acid and glacial acetic acid in accordance with SAE J1681, Gasoline, 

Alcohol and Diesel Surrogates for Materials Testing published by SAE 

International. 

Time and temperature considerations 

The time and temperature conditions necessary to establish the appropriate test 

conditions were carefully considered. In order to practically model performance 

of the dispensing equipment over a reasonable, extended period of time, the use 

of accelerants is necessary. Use of elevated temperature was identified as the 

most appropriate accelerant mechanism. The relationship between exposure 

time and exposure temperature is generally inverse. Elevation of the test 

temperature, based on the Arrhenius principle, will correspond to increased 

chemical interaction. Other testing methodologies for materials in contact with 

automotive fuel were reviewed in consideration of the particular time and 

temperature conditions. After careful consideration, the use of a 60o

C 

conditioning temperature for a 2500-hour exposure was identified as applicable 

for the defined purpose of evaluating response of the dispensing equipment. 

Based on input from manufacturers, 60o

C corresponds well to a peak operating 

ambient for the equipment; while the equipment will not be continuously exposed 

to that temperature in use, testing at that temperature provides some useful 

practical information. Elevation of the conditioning temperature above 60o

C could 

theoretically permit reduced test time; however, exposure of the equipment to 

such temperatures would present practical challenges in performing the tests and 

may possibly have a negative effect on the rate of chemical reaction. Reduction 

of the test temperature would also be feasible, but would require extended 

testing time. For these reasons, 60o

C was selected as the most appropriate 

equipment conditioning temperature. 

Gasket and seal materials are typically exposed to test fluids for 70-hour periods 

prior to assessment on the material level. In addition to the equipment exposure 

protocols outlined above, test exposure times longer than the typical 70-hour 

exposure were reviewed by test as a part of the gasket and seal material test 

program. 

Gasket and Seal Research 

The objective of the research on gasket and seal materials was to validate 

information that had not been supported with specific test data, and assess the 

effects of a number of important variables on material compatibility assessments. 
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Gasket and Seal Test Procedures 

The program consisted of subjecting a number of gasket and seal materials to a 

variety of test conditions. Assorted samples of four seal materials were exposed 

to: 

• Test fluids comprised of 25% and 85% ethanol; 

• Test fluids with and without aggressive components; 

• Exposure times of 70h, 140h, 210h, and 1000h; 

• Room temperature exposure at 23o

C and 60oC exposure; 

• Both the test fluids and water at 60o

C, in order to assess the effects of 

temperature alone versus actual chemical attack; and 

• Test fluids with corrosion inhibitor added in prescribed amounts, to assess 

possible effects of optional corrosion inhibitors on seal materials. 

At the conclusion of the appropriate exposures, specified samples were 

subjected to tensile strength and elongation, volume change, weight extraction, 

and compression set assessments based on requirements in the Standard for 

Gaskets and Seals, UL 157. 

Gasket and Seal Test Results 

Many of the samples yielded results that would be compliant with the 

requirements of UL 157. However, noncompliant results were also observed. 

Because seals play a critical role in preventing loss of fuel containment, these 

findings underscore the need for proper definition of seal compatibility testing 

requirements in order to permit proper selection of gasket and seal materials for 

use in application where exposed to high-percentage ethanol fuel blends. 

Information shared with UL, and available literature, had indicated for most 

materials, the 25% ethanol test fluids would tend to have more potentially 

degrading effects on seal materials. The data generated from the tensile 

strength, elongation, volume change, and extraction tests supports this premise. 

However, while almost all data from the exposure to the 25% ethanol test fluid 

indicated more degradation than exposure to the 85% ethanol test fluid, data also 

indicated the 85% ethanol test fluid may cause more degradation for some 

materials. For this reason, tests with both 25% and 85% ethanol test fluids have 

been required. 

Overall, data for samples exposed to aggressive and non-aggressive fluids 

showed some level of correlation between test fluid and product performance, 

especially for volume change, extraction, and compression set. However, the 

data indicated that in some cases significantly more degradation may occur from 

the aggressive fluid than the non-aggressive fluid. For this reason, to best model 

practical usage with contaminated fuels, and to promote consistent test 

methodologies, testing with the aggressive fluids has been required. 

Samples exposed to the test fluids for longer than 70h tended to demonstrate 

more degradation than those exposed for 70h. Similarly, samples exposed to 
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elevated temperature fluids demonstrated more degradation than corresponding 

samples exposed to the same fluids for the same time at room temperature. 

Elevation of the test temperature, based on the Arrhenius principle, will 

correspond to increased chemical interaction. Samples exposed to water at 60o

C 

performed significantly better than samples exposed to ethanol test fluids at 60o

C, 

demonstrating that the reduction in performance for samples exposed to test 

fluids at 60o

C may be attributed to chemical attack and not only material property 

changes due to elevated temperature. Data generated from 70h exposures at 

60oC generally correlated to data from 1000h exposures at 23oC. Based on this, 

testing either for 70h at 60oC, or for 1000h at 23oC may be appropriate. However, 

testing at room temperature provides major practical benefits. Additionally, the 

formed gaskets are also subjected to the 2500h/60o

C exposure conditions as 

part of the equipment assessment. For these reasons, gasket and seal material 

tests after exposure for 1000h at 23oC have been required. 

Data from samples exposed to test fluids incorporating corrosion inhibitor 

demonstrated little to no effect on seals. 

Gasket and Seal Requirements 

Requirements for the gasket and seal materials used in E85 dispensers were 

based on these findings and published in August 2007. The requirements 

specify exposure of gasket and seal materials for 1000h to both CE25a and 

CE85a test fluids at 23oC. For static seals (seals not subject to movement in 

application), volume change, extraction, and compression set tests are required. 

For dynamic seals (seals subject to movement in application), tensile strength, 

elongation, volume change, and extraction are required. Seals intended for 

static/dynamic applications would need to comply with all applicable tests. 

Tensile strength and elongation after exposures may not be less than 60% of the 

as-received values. Volume change after exposure may not result in more than 

40% increase or more than a 1% decrease. Extraction may not result in more 

than a 10% weight loss after exposure. Based on established best practices, 

compression set is required to be 35% maximum. 

In addition to these material-level performance requirements for gasket and seal 

materials, samples of the formed gaskets and seals will also be tested within the 

equipment during the 2500h/60o

C equipment exposure tests for their ability to 

prevent leaks. 

2500h Conditioning Exposure 

The objective of the 2500h conditioning of the dispensing equipment was to 

review the effects of ethanol test fluids, time and temperature conditions as they 

relate to material compatibility assessments. 

2500h Conditioning Exposure Test Procedures 

This portion of the research program consisted of exposing nearly 40 samples of 

dispensers and dispenser components to test fluids at elevated temperature. 
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Two samples of each assembly were tested, with one exposed to CE25a and the 

second exposed to CE85a. The samples were conditioned for a total of 2500 

hours at an elevated temperature of 60oC. The test fluids were removed and 

replenished on a weekly basis to promote continued chemical interaction of the 

fluids with the test samples. During the weekly drain/refill process, the chamber 

permitted to cool; chamber cool-down and warm-up times were not included in 

the 2500h total. Test fluids drained from the samples were retained for analysis. 

During the weekly drain/refill sessions, the dispenser samples were also 

subjected to a 75 psi leakage test, representing 150% of a nominal dispensing 

system pressure of 50 psi. 

2500h Conditioning Exposure Test Results

The majority of the samples did not demonstrate any leakage during the course 

of the 2500h exposure. However, one sample that had been exposed to CE25a 

exhibited leakage and damage to the seal. After completing approximately 75% 

of the exposure time, the sample did not comply with the weekly 75 psi leakage 

test. The sample was removed from the test chamber at that time. 

Visual examination of the extracted test fluids each week showed discoloration 

compared to virgin test fluid, and indicated that the test fluids had acted upon the 

test samples. The extent of action, and any corresponding effect on safe 

performance of the equipment, was judged by the safety performance-testing 

regimen that followed the conditioning exposure.

Safety Performance Testing 

The samples of dispensing equipment exposed to the conditioning exposure 

program were subjected to the safety performance tests contained in applicable 

UL Standards. The objective of this activity was to assess the performance of 

safety related functions of the dispenser products after exposure to high 

percentage ethanol test fluids. 

Safety Performance Test Procedures 

Samples of each product design that successfully completed the conditioning 

exposure were then subjected to critical performance tests from the applicable 

UL standards covering the devices for petroleum service. 

Hose nozzle valves were subjected to tests from the Standard for Valves for 

Flammable Fluids, UL 842. Tests included: 

• External Leakage Test (Section 13), consisting of 75 psi pressure testing 

with valve closed/outlet open, and 25 psi pressure testing with valve 

open/outlet closed; 

• Endurance Test (Section 21) to assess the ability of the valve to operate 

and stop the flow of fluid for 100,000 cycles; 

• External Leakage Test repeated after the Endurance Test; 

• Hydrostatic Strength Test (Section 22) at 250 psi; and 
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• Electrical Continuity Test (Section 23), to assess the ability of the product 

to maintain electrical continuity. 

Breakaway couplings were subjected to tests from the Standard for Emergency 

Breakaway Fittings, Swivel Connectors, and Pipe-Connection Fittings for 

Petroleum Products and LP-Gas, UL 567. Tests included: 

• Electrical Continuity Test (Section 12), to assess the ability of the product 

to maintain electrical continuity under no pressure and rated pressure 

conditions; 

• External Leakage Test (Section 13), consisting of 75 psi pressure testing; 

• Pull Test (Section 20.2), to ensure that the breakaway separates at an 

appropriate value based on its rating; and 

• Seat Leakage Test (Section 14), to assess adequate closure of the 

breakaway sections after separation. 

Valves actuated by electrical means were subjected to tests from the Standard 

for Electrically Operated Valves, UL 429. Tests included: 

• External Leakage Test (Section 28), consisting of 75 psi pressure testing; 

• Seat Leakage Test (Section 29), to assess adequate closure of the valve; 

• Endurance Test (Section 30) to assess the ability of the valve to operate 

and stop the flow of fluid for 100,000 cycles; and 

• External Leakage Test and Seat Leakage Test repeated after the 

Endurance Test. 

Meters were subjected to tests from the Standard for Meters for Flammable and 

Combustible Liquids and LP-Gas, UL 25. Tests included: 

• Leakage Test (Section 12), consisting of 75 psi pressure testing; 

• Endurance Test (Section 13) to assess the ability of the meter to withstand 

300 hours of flow without leakage through the shaft or other locations; and 

• Leakage Test repeated after the Endurance Test. 

Safety Performance Test Results 

The results from the performance-testing program are summarized in Table 1. 

The intent of the test regimen was to have a sample of each product design 

exposed to each test fluid, and subsequently subjected to the appropriate 

performance tests from the relevant standard. In some cases, multiple samples 

of the same product design were exposed to the test fluids. Each conditioned 

sample was subjected to an External Leakage Test at the conclusion of the 

exposure. However, each conditioned sample of every product design was not 

subjected to the full range of performance tests. In the interest of clarity, only 

test results for samples subjected to the full range of appropriate performance 

tests are shown. 
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Table 1 – Summary Of Performance Testing Program Findings 

Part Test 

Fluid 

Tests a Results & Comments 

Hose Nozzle 

Valve Design #1 

CE85a EL, E, 

ELR, H, 

EC 

External Leakage, Endurance, Hydrostatic & Electrical Continuity Test 

results were compliant. During External Leakage Test repeated after 

Endurance, leakage occurred through the vacuum cap with the valve 

open/outlet closed. Noncompliant. 

Hose Nozzle 

Valve Design #2 

CE25a EL, H, 

EC, E 

Component level sample. External Leakage, Hydrostatic, and 

Electrical Continuity Test results were compliant. Sample would not 

open and could not be shown to pass the Endurance Test. 

Hose Nozzle 

Valve Design #2 

CE25a EL, E, H, 

ELR, EC 

System level sample. All results compliant. 

Hose Nozzle 

Valve Design #2 

CE85a EL, H, 

EC, E 

Component level sample. External Leakage, Hydrostatic, and 

Electrical Continuity Test results were compliant. Sample would not 

open and could not be shown to pass the Endurance Test. 

Hose Nozzle 

Valve Design #2 

CE85a EL, H, C System level sample. External Leakage, Hydrostatic, and Electrical 

Continuity Test results were compliant. Sample would not open and 

could not be shown to pass the Endurance Test. 

Hose Nozzle 

Valve Design #2 

CE85a EL, E, H 

ELR, EC 

System level sample. All test results compliant. 

Breakaway 

Coupling 

CE25a EC, EL, 

SL, P 

All test results compliant. 

Breakaway 

Coupling 

CE85a EC, EL, 

SL, P 

All test results compliant. 

Valve Design #1 CE25a EL, SL No leakage at the conclusion of the 2500-hour exposure. Sample 

showed leakage at approximately 11,000 cycles during the Endurance 

Test. Noncompliant.

Valve Design #1 CE85a EL, SL, E, 

ELR, SLR 

All test results compliant. 

Valve Design #2 CE25a EL, SL, E All test results compliant. 

Valve Design #2 CE85a EL, SL, E All test results compliant. 

Valve Design #3 CE25a EL, SL, E All test results compliant. 

Valve Design #3 CE85a EL, SL, E All test results compliant. 

Meter Design #1 CE25a EL, E, 

ELR 

No leakage at the conclusion of the 2500-hour exposure. The sample 

was unable to complete the Endurance Test and stopped flow after 

approximately 83% completion. When Leakage Test was repeated 

after the Endurance Test, leakage occurred. 

Meter Design #1 CE85a EL, E, 

ELR 

No leakage at the conclusion of the 2500h exposure. When Leakage 

Test was repeated after the Endurance Test, leakage occurred. 

Noncompliant. 

Meter Design #2 CE25a None Sample not tested due to leakage during the 2500h exposure. 

Meter Design #2 CE85a EL, E No leakage at the conclusion of the 2500h exposure. During the 

Endurance Test, after approximately 8% completion, leakage 

occurred. Noncompliant. 

Meter Design #3 CE25a EL, E Leakage occurred after Endurance. 

Meter Design #3 CE85a EL, E Leakage occurred after Endurance. 

Table 1 Note: 

a - Test codes designate the following tests, performed as required by the applicable UL standard: 

E Endurance test 

EC Electrical Continuity 

EL External Leakage at 75 psi 

ELR External Leakage, repeated after Endurance Test 

H Hydrostatic test at 250 psi 

P Breakaway pull test 

SL Seat Leakage at 75 psi 

SLR Seat Leakage, repeated after Endurance Test 

While the performance of some test samples was good, the overall test results 

support the conclusion that high percentage ethanol fuels can degrade materials. 

This material degradation can in turn affect the ability of the products to meet the 
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safety performance requirements contained in UL’s standards. This was 

manifested in the sample population in the form of leakage from sealed joints on 

the equipment, gumming of seals, locking of moving parts in a manner that 

prohibits non-safety related functionality, and some visual evidence of corrosion. 

The majority of the noncompliant test results were generated by the root cause of 

gasket or seal failure. Improved selection of gasket and seal materials should 

provide a significant improvement in the ability of designs to comply with test 

requirements. Sectioning analysis of the test samples showed some corrosion in 

the fuel path, although test results indicated that most action on the metallic 

structures did not result in degradation that could lead to a safety concern. The 

exception would be the mechanisms causing the hose nozzle valves and meters 

to become inoperable; while the test samples did not demonstrate leakage, the 

locking of internal moving parts is undesirable. 

As previously noted in the gasket and seal research program, testing with CE25a 

fluids can be more degrading in some cases than testing with CE85a. This 

pattern was noted in the performance testing as well. Several products showed 

better performance for samples exposed to CE85a than samples exposed to 

CE25a. 

The issue of galvanic interaction at metallic interfaces is one that is important to 

address for high percentage ethanol/gasoline fuel blends. Galvanic interaction 

may be addressed by requiring all testing on a system level (i.e. testing every 

permutation of all component interfaces through the fuel path); however, there 

are significant practical benefits to being able to test subassemblies discretely 

and specify permitted combinations for connection in the factory or field. Some 

of the discrete component samples were identical to those built into the 

dispenser samples, but the discrete samples were capped off with plugs made of 

the same material that they were to be connected to in the dispensers. The 

relative performance of the discrete samples supported component level testing 

to address galvanic interaction. The 2500h exposure test is to be conducted on 

a component level with plugs of the most galvanically incompatible materials 

permitted by the manufacturer. At this time, in the absence of information 

specific to high percentage ethanol/gasoline fuel blends, the “Galvanic Series of 

Metals Exposed to Seawater” Table from the NACE Corrosion Engineer’s 

Reference Book, published by NACE International, has been identified as the 

most appropriate basis for the determination of galvanic incompatibility. 

Materials permitted by the manufacturer but not included in this Table are 

addressed by subjecting samples employing the material interface to the 2500h 

test. 

Many gasket and seal materials swell when exposed to ethanol. When exposure 

is ended, the seals may exhibit a reduction in volume known as “dry-out.” After 

exposure to the ethanol fluids was terminated in the research, the tendency of 

the gaskets and seals to dry out rapidly was noted in the handling of the test 
13 

samples. The practical effect on the research testing was minimal. However, 

this phenomenon underscored the need to include measures in the requirements 

to minimize the risk of leakages in practice due to dry-out. 

Analytical Testing 

Analytical tests were performed on the ethanol-blended test fluids that were 

drained from samples of dispensers and dispenser subassemblies used in the 

2500h conditioning exposure. The objective of this activity was to analyze the 

extracted test fluids in order to identify various extracted or deposited elements 

and organic compounds resulting from the exposure of the equipment to the high 

percentage ethanol test fluids. The analytical procedures focused on both 

inorganic and organic compounds. 

Analytical Test Procedures

Two types of analytical procedures were used to analyze the test fluids. 

Inductively Coupled Plasma/Mass Spectroscopy (ICP/MS) was used to analyze 

an aqueous extract of the test fluids. Gas Chromatography/Mass Spectroscopy 

(GC/MS) was used to analyze the entire test fluid sample (including water, acids 

and salts). 

The samples for ICP/MS analysis were prepared by first adding a combination of 

a 5% acid solution and a water-insoluble organic solvent to the test fluid samples. 

This mixture was then shaken to achieve an even distribution of the fluids. After 

the sample was allowed to rest, two distinct layers were formed: 

a) An organic layer, which contained the water-insoluble organic content of 

the fluids, and 

b) An aqueous layer that was assumed to contain any water-soluble 

inorganic elements arising from metallic corrosion of the equipment 

samples.

The ICP/MS analysis was specifically focused on nineteen separate elements: 

aluminum, antimony, barium, beryllium, cadmium, chromium, copper, iron, lead, 

lithium, manganese, molybdenum, nickel, silver, thallium, tin, titanium, vanadium, 

and zinc. 

The GC/MS organics analysis consisted of testing the unmodified fluid samples 

(fluid directly from the samples including water, salts and acids) against 

references. These included a reference standard library of 40 compounds as 

well as the use of Wiley Library’s search library of approximately 200,000 

compounds for the identification of TICs (Tentatively Identified Compounds) 

based upon the retention times of internally added reference compounds. 

 

Analytical Test Results 

The ICP/MS and GC/MS data indicated that CE25a and CE85a test fluids exhibit 

different behavior against the metals and polymeric materials of the dispenser 

components. Differences in the both concentration and ranking of inorganic 
14 

elements arising from the samples were noted, with those in extracted CE85a 

being more pronounced. The organics analysis shows less of a differential effect 

between the two fluids. These results reinforce the need to use both the CE85a 

and CE25a test fluids. 

The ICP/MS analysis indicated the presence of high concentrations of zinc and 

aluminum in the aqueous phase for both CE25a and CE85a fluids. Lesser 

concentrations of copper, nickel, tin, iron, lead and barium were measured in 

both types of extracted test fluids. Additionally, comparisons between element 

compositions in the test fluids drawn from plated and unplated samples show that 

the use of plating (typically nickel) and surface treatments (such as anodizing) is 

generally effective as a means to mitigate the extraction of material. 

Substantial extraction of organic compounds was noted for CE25a and CE85a 

test fluids. Over 200 organic compounds were extracted from the assorted 

equipment under test. The extraordinary number of extracted compounds 

includes significant levels of plasticizers, stabilizers, polymer modifiers, oligomers, 

and antioxidants. The effects of the removal of these compounds is evident in 

the resultant performance of the formed parts in the safety performance testing 

program, especially as it relates to the performance of seals. 

The presence of significant numbers and levels of extracted material in the test 

fluids may indicate a potential effect on fuel quality. The research test protocol 

that was used exposed the equipment to the test fluid for a one-week period at 

elevated temperature to accelerate the chemical interaction of the fluid with the 

equipment. Accordingly, the concentrations of extracted compounds in the test 

fluid would be expected to be higher than concentrations in practical dispensing 

of ethanol fuel. However, the tendency of the ethanol fluids to extract both 

organic and inorganic materials over time from the dispenser path was noted. 

The issue of fuel quality is independent of the safety certification of the dispenser 

equipment, and was not within the scope of this research program. 

Harvested Sample Assessments 

Samples of products from the field that had been in service dispensing highpercentage ethanol fuel blends were harvested. These harvested samples were 

analyzed, and when possible, subjected to performance testing from the UL 

Standard that would cover the device for petroleum service. The objective of this 

activity was to obtain information from examinations and assessments of 

products that have been in actual service with high percentage ethanol fuel 

blends. 

In February 2007, UL published “Survey of E85 Dispensing Operations in the 

U.S.” documenting findings from visits to E85 dispensing locations in the United 

States. In March 2007, “Ethanol Fuel Dispensing Operations in Brazil” was 

published. The results of these qualitative surveys indicated a favorable history of 
15 

dispensing high percentage ethanol fuel blends, but based on practical limitations 

did not allow for the generation of test data. 

Numerous samples of components and dispensers were harvested from a variety 

of sources. Many of the products had been in service dispensing hydrated 

ethanol fuel (without the gasoline component) in Brazil; however, some of the 

samples had been in use in the United States. The usage conditions for the 

harvested samples range from short-time use to multi-year use, dispensing a 

variety of fuels. For some samples, specific use conditions were not available. 

Samples were obtained from equipment manufacturers and independent users. 

Harvested Sample Test Procedures 

The samples were subjected to leakage testing and relevant safety performance 

testing from the applicable UL standard covering the type of equipment for 

petroleum service, as previously noted. The applicable tests from the UL 

standards are “type tests” - meaning that dedicated test samples are subjected to 

the test protocol rather than samples that have been in actual service. However, 

in assessing the ability of these harvested samples to contain fuels and to 

perform their intended safety functions, the applicable UL type tests were 

identified as the best analytical method. Further, the general approach of 

performance testing after fuel exposure follows the conceptual plan of the 

conditioning research. 

Harvested Sample Results

The harvested samples demonstrated degradation across a continuum that may 

correspond to wide conditions of use, length of use, and conditions of 

maintenance. Some of the samples showed no signs of degradation and were in 

premium condition. Some samples showed degradation and did not comply with 

applicable tests. The compliance of other samples could not be verified because 

of their condition. The results from the harvested sample test program are 

summarized in Table 2. 
16 

Table 2 – Summary Of Harvested Sample Findings 

Part Fuel 

Dispensed 

Service 

(Yrs) 

Volume 

(Gal) 

Tests b Comments 

Dispenser E85 Unknown Unknown L No leakage. 

Dispenser E85 7 Unknown L No leakage 

Filter casting/ 

filter element 

Hydrated 

ethanola

7 Unknown L, V No leakage. No visible deterioration. e

Filter casting/ 

filter element 

Hydrated 

ethanola

2 29,059 L, V No leakage. No visible deterioration. e 

Hose breakaway Hydrated 

ethanola

2.5 39,626 P Separated at 400 lbs; inconclusive. c

 

Hose E85 7 Unknown L Results compliant. 

Hose E85 7 Unknown L Leakage at coupling at 8 psi. 

Hose breakaway E85 7 Unknown EC, L, P Seat leakage after Pull test 

noncompliant. 

Hose breakaway E85 7 Unknown EC, L, P Separated at 593 lbs.; noncompliant. 

Seat leakage after Pull test 

noncompliant. 

Hose nozzle Hydrated 

ethanola

1 5812 A, L, V No leakage. Analytical tests on white 

residue. 

Hose nozzle Hydrated 

ethanola

2 7793 L,V No leakage. Traces of white residue. 

Hose nozzle Hydrated 

ethanola

3 9775 L,V No leakage. Traces of white residue. 

Hose nozzle Hydrated 

ethanola

3.5 10,270 A, L, V Leakage from spout at 20 psi. 

Analytical tests on white residue. 

Hose nozzle Hydrated 

ethanola

7 Unknown H, L Results compliant. 

Hose nozzle Hydrated 

ethanola

7 Unknown H, L Results compliant. 

Hose Nozzle E85 7 Unknown EC, L Results compliant. 

Hose Nozzle E85 7 Unknown EC, L Results compliant. 

Hose nozzle 

/hose/breakaway 

Hydrated 

ethanola

2.5 39,626 H, L Hydrostatic passed. No leakage. 

Meter E85 3 13,000 L, V Results compliant. 

Meter Hydrated 

ethanola

7 Unknown L, V Sample showed noncompliant leakage 

test results at 7 psi. No visible 

deterioration. d

Meter body / 

manifold casting 

Hydrated 

ethanola

2.5 39,626 V Sample not complete and could not be 

tested. No visible deterioration. 

Meter E85 7 Unknown L Results compliant. 

Hose nozzle 

/hose/breakaway 

E85 Unknown Unknown L, P Results compliant. 

Nozzle 

breakaway 

Unknown Unknown Unknown L Leakage at 20 psi. 

Nozzle 

breakaway 

Unknown Unknown Unknown V Sample broke while attaching pipe for 

leakage test. Signs of wear. 

Nozzle 

breakaway 

Unknown Unknown Unknown L Results compliant. 

Pressure 

actuator 

assembly 

E85 Unknown Unknown L Leakage at 25 psi. 

Swivel Unknown Unknown Unknown L Results compliant.

Swivel Unknown Unknown Unknown L Results compliant.

Swivel Unknown Unknown Unknown L Results compliant.

Swivel Unknown Unknown Unknown L Results compliant.

Swivel E85 7 Unknown EC, L Results compliant.

Swivel E85 7 Unknown EC, L Results compliant.

Solenoid valve E85 3 13,000 L, V Results compliant. 

Solenoid valve Hydrated 

ethanola

Unknown Unknown V Sample incomplete and could not be 

tested. No visible deterioration. 

Solenoid valve Hydrated 

ethanola

2.5 39,626 V Sample not complete and could not be 

tested. No visible deterioration. 
17 

Table 2 Notes: 

a - Brazilian hydrated ethanol fuel, nominally 93% ethanol / 7% water. 

b - Test codes designate the following testing and analytical procedures: 

A Analytical analysis of residues 

E Endurance test 

EC Electrical Continuity test 

H 250 psi hydrostatic test 

L 75 psi leakage test 

P Breakaway pull test 

V Visual examination

c- Breakaways are required to separate at a force that is above 100 lbs and not more than their 

rated value, which is marked on the breakaway. Due to wear and build-up of residue it was 

impossible to determine the marked separation rating to verify compliance with the rated value. 

d - The harvested sample was incomplete and needed to be mated with other parts in order to be 

tested. The sample has three connection points and four additional closures. New mating parts 

and o-rings were connected to the three connection points of the harvested sample to complete the 

leakage test. Leakage was observed through the four unmodified closures. The modified 

connection points complied with the leakage test requirements. 

e - The harvested samples were incomplete and needed to be mated with other parts in order to be 

tested. New mating parts and gaskets were connected to the harvested samples to complete the 

leakage test. The resultant assemblies complied with the requirements after these modifications. 

Practical considerations limit the conclusions that can be drawn from testing of 

harvested samples, some of which have unspecified usage history and have 

been removed from service for undefined reasons and periods. However, 

acknowledging these limitations, the harvested sample research program 

provided useful information. 

While many harvested samples in this limited population performed well, the 

noncompliant results indicate that high percentage ethanol fuel blends can 

degrade materials and possibly result in degradation to products that may affect 

their ability to meet the performance requirements of UL’s standards. This was 

manifested in the harvested sample population primarily in the form of leakage 

from sealed joints on the equipment. Visual evidence of degradation was also 

noted in some cases.

Several samples demonstrated deposits of white residue in the form of deposited 

powder on the interior surfaces of the fluid path. This powder was removed and 

subjected to chemical analysis in order to determine the constituents of the 

residue. The analysis indicated the presence of chromium, copper, iron, 

magnesium, manganese, and zinc. The results did not demonstrate the 

presence of aluminum, which formed the major material used in the construction 

of this equipment. It appears that the residue was result of contaminated fuel 

being handled by the equipment, although information on the source of the 

residue is not conclusive. 
18 

Equipment Requirements 

After reviewing the equipment research test results, the equipment testing 

protocols were defined. Samples are required to be exposed to CE25a and 

CE85a test fluids for a period of 2500h at 60o

C. The samples are prepared with 

plugs of the most galvanically incompatible materials, and as needed other 

materials of undefined galvanic incompatibility. At the conclusion of the 2500h 

exposure, the samples are subjected to the applicable safety performance tests 

from applicable UL standards. 

The evaluation strategy using both CE85a and CE25a test fluids yields many 

benefits. This strategy best addresses the reactions of both metallic and nonmetallic dispenser materials in the concentrations most likely to cause 

degradation. Testing with both fluids addresses the present range of E85 fuel 

blends based on seasonal and geographical variations. This strategy also 

accommodates blending dispenser designs that may have variable ethanol 

percentages in the fuel path. The strategy also anticipates ethanol/gasoline fuel 

blends in the 15+

 to 25% ethanol range that are not yet nationally available, but 

are being piloted in Minnesota and under strong consideration for future usage 

on a national scale with all vehicles accepting gasoline. Finally, the plan 

presents a single, clear rating for products intended for ethanol blended fuel use 

that will simplify acceptance by Authorities Having Jurisdiction and other 

interested parties. 

The research demonstrated that the action of the CE25a fluid and the 

consequential effects on materials are different than that of the CE85a fluid. The 

research has also shown that commercially available dispenser products can be 

designed to meet requirements. In some cases more careful selection of gasket 

and seal materials in particular may be needed to address the lower ethanol 

concentration represented by the CE25a test condition. 

The defined research program met its objective of permitting the identification of 

requirements for the design and performance of dispensing equipment for high 

percentage ethanol/gasoline fuel blends. These detailed requirements are 

documented in the Outline of Investigation for Power-Operated Dispensing 

Devices for Gasoline/Ethanol Blends With Ethanol Content Greater than 15%, 

Subject 87A, which was published by UL in October 2007. A second edition was 

published in November 2007 with additional requirements for vapor recovery. 

The requirements define performance-based protocols for assessment of the 

safety of a variety of materials integrated into a particular dispensing equipment 

design. 

Conclusion 

The research program has validated important premises and has supported the 

development of a test regimen and certification program for E85 dispensers. 
19 

The data generated during the program shows that some commercially available 

materials and equipment would be expected to comply with the certification 

requirements and be suitable for use with E85. Additionally, some of the 

harvested products in use dispensing high percentage ethanol/gasoline fuel 

blends were in good to excellent condition. These results indicate that proper 

material selection, material application, and equipment design can be practically 

implemented to accomplish safe dispensing of E85. 

Some commercially available materials or equipment may not pass the 

necessary requirements, or may not pass the necessary requirements for a 

particular application. The test data clearly demonstrate high percentage 

ethanol/gasoline fuel blends can act in a significant manner on materials in the 

fuel path of a dispenser, can degrade materials that are not appropriately 

selected or applied, and can negatively affect the safe performance of the 

equipment. Careful selection and application of appropriate materials for use in 

E85 dispensers is necessary. In particular, careful selection and application of 

seal materials is expected to produce a significant and rapid improvement in the 

performance of these products. 

UL has established appropriate equipment testing methodologies and 

certification requirements for dispensing equipment intended for use with high 

percentage ethanol/gasoline fuel blends. The requirements constitute 

reasonable measures to mitigate the effects of exposure to these fuels. 

While the immediate goal of defining requirements for the safety of dispensing 

equipment has been addressed, there are ongoing efforts to build additional 

technical insight into the effects of dispensing high percentage ethanol/gasoline 

fuel blends on materials and equipment. The US Department of Energy (DOE) is 

leading work to which UL and others are providing knowledge support related to 

research of fire characteristics of E85 blends. UL is collaborating with DOE, Oak 

Ridge National Laboratories, the National Renewable Energy Laboratory, and the 

Environmental Protection Agency’s National Vehicle Fuel Emissions Laboratory 

to conduct additional experiments with moving test fluids. Other research work 

may be appropriate to address this quickly developing sector. Organizations 

having responsibility for fuel quality and collateral effects of extracted compounds 

in high percentage ethanol/gasoline fuel blends for internal combustion engines 

may need to consider future research. 

Acknowledgements 

UL acknowledges the support of Dennis Smith of the United States Department of Energy and 

Wendy Clark of the National Renewable Energy Laboratory, who have freely shared their time 

and extensive knowledge in support of this work. UL also acknowledges the support of experts 

who shared their considerable experience with our organization in the completion of our research 

program and development of requirements. 

The author gratefully acknowledges the support of Joe Bablo, Gus Schaefer, Suzanne Lavin, 

Dennis Apostolou, and Tom Chapin of UL.