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OAR Box 1194 

Prepped by Candice Davis 

Document Number: 

52) ll-F-2 

Docket Number: 

A-90-15 

Printed 5/13/2008 10:52:15 AM Sheet 52 of 89 
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..tn.'--.. 

/ f% \ • UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

'. ^S&2. % Environmental Criteria and Assessment Office (MD-52) 

%, / Research Triangle Park, North Carolina 27711 

June 26, 1990 

Dr. Charles Gray 

Director of Emissions Control Technology Division \ h 

U.S. Environmental Protection Agency \ 

2565 Plymouth Road ; " . 

Ann Arbor, Michigan 48105 ~* 

Dear Dr. Gray: 

The report, "An Analysis of Possible Health Effects Due to the Use of a 

Copper Diesel Fuel Additive", you submitted to us proposes the use of copper as 

a diesel fuel additive in conjunction with traps capable of undergoing 

regeneration during engine operation. Regeneration is made possible by the 

copper additive which lowers the reaction temperature of the trap constituents. 

The report discusses copper toxicity, gives test results, from the trap-pluscopper additive, calculates incremental ambient copper and other air pollutant 

concentrations with trap use, and provides the necessary background information 

supporting these tasks. 

Copper and particulate toxicity. The normal homeostatic mechanism for 

copper appears to possess a great deal of reserve capacity and could be expected 

to protect exposed organisms against adverse effects of exposure far in excess 

of those encountered from normal environmental sources. Normal copper exposure 

is from water and food intake and amounts to 2-5 mg/day. Most intoxications of 

copper occur from ingestion of amounts in excess of one gram which overwhelm the 

normal homeostatic mechanisms governing copper absorption, distribution, and 

elimination. Less than 1% of daily copper intake is derived from the air. Fifty 

percent of inhaled particulate copper is deposited in the lungs; and 40% of that 

absorbed while 40% is retained in the lung, and the remainder cleared by 

mucociliary escalation. The chemical form of particulate copper from diesel 

engines using a copper fuel additive is unknown. Since the chemical form is 

likely insoluble, however, the absorption from the respiratory tract may be lower 

than the estimate above. 

Relatively few reports of copper toxicity exist in the literature. No 

epidemiological data exist which show that copper per se is carcinogenic, and 

no evidence of adverse human health effects from exposure to airborne copper 

exists. Contact dermatitis, mild anemia, and leukocytosis have been reported 

as a result of chronic exposure. The carcinogenic potential of copper and copper 

compounds has not been adequately evaluated in experimental animals. Cupric ion 

is a potential mutagenic agent, however. High doses of copper given to pregnant 

mice dams caused teratogenic effects in fetuses. Sensitive individuals with 

Wilson's disease may experience progressive liver degeneration when exposed to 
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high levels of copper. Individuals with hereditary deficiencies of glucose 6-

phosphate dehydrogenase are also sensitive to the hemolytic effects of excess 

|F copper. 

This report has successfully established a relatively low toxicity of 

copper. 

Test results from trap-plus-copper additive,, The copper additive was used 

in tests with diesel engines under conditions of cold start and hot start. Both 

cold-start and hot-start tests showed reductions in hydrocarbons, nitrogen 

oxides, and particulates when the copper additive (10 ppm) and trap were used. 

Particulates were reduced 87.4% during hot-start testing. Polycyclic aromatic 

hydrocarbons (PAH) were reduced from 47.5% for benzo(g,h,i)fluoranthene to 76.5% 

for benzo(a)pyrene. Pyrene increased 53.8%, however. Lesser, but significant, 

decreases in PAH (except pyrene) occurred under cold-start conditions. An 

increased exhaust back pressure which forces the engine to work harder caused 

a carbon monoxide increase of 43.4% during hot start-testing. Soot as a fraction 

of the particulate mass was reduced from 30% to 3%. 

The decrease in carcinogenic PAH such as benzo(a)pyrene is a significant 

benefit of the trap and copper fuel additive system. 

Incremental copper and other air pollutants. Roadway modeling was used 

to predict copper concentrations for various scenarios. Street canyon modeling 

predicted a concentration of 0.4 mg copper/m3 for the average case, and roadway 

tunnel modeling predicted a concentration of 14.3 ng copper/m3 for that average 

case. Under extreme travel conditions an increase of 36 ng copper/m3 was 

predicted. At a distance 100 meters from the freeway a concentration of 5 ng/m3 

was predicted. The ACGIH has recommended a copper exposure limit of 0.2 mg/m3 

for copper fumes and 1.0 mg/m3 for dust. The average ambient copper 

concentration in the U.S is about 75 ng/m3. The particle size distribution in 

the emissions from the tests with and with out the trap and copper fuel additive 

did not change though the total amount of particulate did decrease with the use 

of the trap and copper fuel additive. 

Thus, increments of copper in the ambient air resulting from the use of 

a copper additive in diesel fuel will be well under exposure levels that cause 

effects. Use of the emission control technology involving the copper fuel 

additive and trap should reduce the carcinogenic activity of the exhaust reducing 

particulate matter and associated PAHs. 

Conclusions. The relatively low toxicity of copper and the roadway models 

are convincing. Copper exposure from use of a copper amended diesel fuel in 

trap-equipped engines should not occur at deleterious levels in the ambient air. 

Reduction of PAH levels with use of the copper fuel additive and trap-equipped 

engines should also reduce the carcinogenic activity of diesel exhaust. However, 

reducing carcinogenic activity by 80%, as seen with use of copper amended diesel 

fuel and traps, does not necessarily assure that risk levels in the area of 

10"5 can be achieved. Roadway models should be used to determine particulate 

concentrations and carcinogenic risk under scenarios similar to the ones used 

for copper in this report. 
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I f you wish to discuss this report further, I can be contacted at (919) 

541-415.5. 

Sincerely, 

Chon Shoaf, Ph.D. 

Chief, Hazardous Pollutant Assessment Branch