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Waste Analysis of Antifreeze



Waste Antifreeze Summary

Of the initial twenty-two (22) samples taken, fifteen (15) returned with hazardous waste results for Arsenic and/or Selenium, with the presence of the two toxins above the regulatory threshold level of 5.0 and 1.0 mg/L, respectively. The samples were from taken ten different dealership facilities.

 

The project staff embarked on research to determine the source of the contaminants. Web research showed a strong possibility that Arsenic and Selenium were present from the metal fabrication process that takes place in building automobiles. Some inquiry to the dealerships was conducted to determine if the antifreeze was being changed out in new vehicles upon arrival from the automaker (that was not the case).  

 

Samples of virgin antifreeze were sent to the laboratory with the intent to eliminate the virgin product as the source of the toxins. Surprisingly, the samples came back with the presence of the two toxins, Arsenic and Selenium. The Selenium was above the regulatory threshold level of 1.0 mg/L in the virgin samples. With the virgin samples coming back hazardous the research on the manufacturing process was discontinued.

 

The TCLP results were presented and discussed with the National Oil Recycling Association (NORA) Antifreeze Work Group meeting in Scottsdale, AZ on February 1, 2006. All members present agreed that a testing problem was the cause of the results. The group overwhelmingly agreed that there was no possibility of Arsenic or Selenium at levels exceeding the regulatory limit was possible in virgin antifreeze. They also suggested that one or more of the additives in antifreeze was causing interference in the matrix of the tests.

 

At the laboratory the information was discussed. Experts in glycol were contacted but had very little experience with waste analysis so were unable to identify the potential inference. The lab diligently studied the test results looking for any anomalies. The lab explained that the standard TCLP analysis (protocol ICP SW 6010) determined the presence of heavy metals through a process of elimination in which graphs of the chemicals presence in the test material were compared to the known graphs of the eight heavy metals. When the peaks of the two graphs align then the toxin is reported to be present.

 

Upon scrutiny of the Arsenic and Selenium graphs it was determined that the two peaks were, in fact, slightly different. The lab then identified two other tests that identified metals in another way that could be used to verify or refute the presence of Arsenic or Selenium in antifreeze. Those tests are through the use of a mass spectrometer or a graphite furnace known as SW6020 and SW7060 respectively.

 

Six samples including duplicates were submitted to the laboratory for testing using all three methodologies. The new samples were taken from three of the sites that originally had received hazardous waste results. The standard SW6010 procedure once again showed the presence of Arsenic and Selenium above the regulatory threshold. The mass spectrometer and graphite furnace tests then refuted the presence of the heavy metals and the waste was determined to be non-hazardous without much additional expense for the testing procedures. The lab was unable to identify the interference by name.

 

Antifreeze sampling was resumed. The sites with previous hazardous results were re-sampled and found to be non-hazardous through the use of the mass spectrometer and graphite furnace but still erroneously indicated the presence of Arsenic and/or Selenium at levels above the regulatory limits when using the standard TCLP procedure (SW6010).   

 

It was interesting that samples from the same facilities were able to reproduce the erroneous Arsenic and Selenium results indicating some common denominator that we were not able to identify.

 

In the data set the only sites determined to have hazardous antifreeze were those that tested positive for the presence of Tetrachloroethene above the regulatory limit. In all cases those shops were using chlorinated brake cleaner, often as a general cleaning agent, and the toxin was also often present in their sump sludge.

 

Antifreeze TCLP Test Results Summary

Heavy Metals:

Arsenic................................................................ Not present in antifreeze but a testing anomaly was identified.
Barium................................................................... .Detected at very low levels in three cases (one was virgin).

Cadmium................................................................................................................. Not detected in antifreeze.

Chromium................................................................................................ Detected at low levels in three cases.

Lead........................... Detected in 1/3 of the samples below the threshold except in one case it was hazardous.

Mercury.................................................................................................................. Not detected in antifreeze.

Selenium.............................................................. Not present in antifreeze but a testing anomaly was identified.

Silver....................................................................................................................... Not detected in antifreeze.

VOCs:

Benzene............................................................................................. Detected at very low levels in two cases.

Methyl Ethyl Ketone................................................................................................ Not detected in antifreeze.

Carbon Tetrachloride............................................................................................... Not detected in antifreeze.

Chlorobenzene......................................................................................................... Not detected in antifreeze.

Chloroform.............................................................................................................. Not detected in antifreeze.

1,2-Dichloroethane.................................................................................................. Not detected in antifreeze.

1,1-Dichloroethene.................................................................................................. Not detected in antifreeze.

Tetrachloroethene                                                                               Detected in ¼ of the samples with 9 cases being hazardous.

Trichloroethene                                                                                                                                             Detected in one case.

Vinyl Chloride                                                                                                                                        Not detected in antifreeze.

 

 

 

Sue Schauls

Program Manager

 

Iowa Waste Reduction Center

University of Northern Iowa

Suite 113, BCS Building

Cedar Falls, Iowa 50614-0185

319/273-6592 (direct line)

319/273-8905 (office)

www.IWRC.org