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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 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. 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 319/273-6592 (direct line) 319/273-8905 (office) |