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Regulatory Issues and the EPA's Used Oil Management Standards Use of Refrigerant Leak Detectors to Screen for Total Halogens

Alvia Gaskill, Jr. Environmental Reference Materials, Inc.

P.O. Box 12527 Research Triangle Park, N.C. 27709

Paper in the Proceedings of the EPA/AWMA 14* International Symposium on the Measurement of Toxic and Related Air

Pollutants, Research Triangle Park, North Carolina, September 12 14,2000

Regulatory Issues and the EPA's Used OH Management Standards-Use of Refrigerant Leak Detectors to Screen for Total Halogens AMa GaskUl, Jr Environmental Reference Materials, Inc. P.O. Box 12527 Research Triangle Park, N.C. 27709 ABSTRACT EPA regulations (40 CFR Part 279) as well as certain state regulations, set limits for the level of total halogens in used oil to be recycled into new oil or burned as fuel. This is done to reduce the emissions of hazardous chlorinated solvents and their by-products, including hydrochloric acid. Although EPA and ASTM field methods developed specifically for measuring the total halogen content are available, for cost reasons, many oil recyclers use hand-held refiigerant leak detectors to screen the oil by measuring the headspace above the oil and using this measurement to estimate the oil phase concentration. Since the regulations do not require that testing be performed, only a certification of the quality of the oil, which may be based on process or other knowledge, any test method may also be used. The results of an evaluation of the effectiveness of leak detectors in screening used oil for total halogens are presented. In comparison with EPA laboratory and field methods, the leak detectors were unable to detect halogens in oils contaminated with low volatility halogenated species such as those found in cutting oils and PCBs, even at percent levels. TTie leak detectors also produced an excessive number of false negative responses for volatile halogenated species in testing at low temperatures (0-32"F) and under windy conditions likely to be found in field situations. Many false positives were also found due to gasoline and oxygenated solvents frequently foimd in used oil such as acetone and MEK. Because the leak detectors are an uiu^liable tool for screening used oil, the recyclers should use the EPA or ASTM methods. Recommendations are given for creating financial incentives to encourage recyclers to switch to the EPA methods. INTRODUCTION More than 1 billion gallons of used oil torn automotive and industrial sources are burned as fijel or re-refined into new lubricating oil basestock in the U.S. annually. EPA used oil regulations limit the level of total halogens (interpreted by EPA to mean total chlorine) in these used oils to protect humans and the environment fix)m exposure to hazardous and toxic halogenated contaminants in the oils that might be released or formed during burning or processing' . These regulations set a 1000 ppm limit for total halogens above which the oil is presumed to be mixed with halogenated degreasing or spent solvents, e.g., chlorobenzcne, methylene

chloride, perchloroethylene, 1,1,1-trichloroethane. Until proven otherwise, any oil containing more than this limit is considered a hazardous waste and cannot be burned as fuel in small boilers or recycled into new oil. If it can be shown that the halogens are due to salts or chlorinated parafSns, the other principal sources of halogens, the oil may still be burned or recycled with relatively few restrictions up to a limit of 4000 ppm. Above this limit, the oil is considered off-specification due to the potential for excess HCl formation and can only be bumed as fuel in large industrial boilers and fumacK which meet other EPA requirements. The EPA regulations allow either knowledge of the history of the oil in question or testing to be used to determine the oil's regulatory status. No testing methods or frequency are prescribed in the regulations and oil recycling industry practices approved by the EPA range from no testing to testing of every load picked up from the original generator of the used oil. To assist recyclers in complymg with these regulations and regulatory agencies in enforcing them, EPA and the American Society for Testing and Materials (ASTM) developed several test methods for determining total halogens in used oil". These include laboratory methods based on oxygen bomb combustion/ion chromatography (EPA SW-846 Methods 5050/9056) and field test kit methods based on sodium dehalogenation/mercuric nitrate titration (EPA SW-846 9077 and ASTM D5384). The field test kit methods have been widely used due to their ability to provide an on-site measurement of the total halogen content in about 10 minutes, thus allowing recyclers to make on the spot decisions about the regulatory classification of a load of used oil from a particular generator, before it is combined with loads from other generators. However, many recyclcrs do not use the test kits or only use them on certain samples, citing the cost per test ($5) and the time required to perform the test as excessive when apphed to all loads. Instead, these recyclers use hand-held battery powered electronic refiigerant leak detectors to screen used oil samples for total halogens by measuring the headspace atmosphere above the oil samples and attempting to relate the gas phase measurement to the oil phase concentration. The leak detectors cost on average $150-200 each and are often used for years. Thus, they are much less expensive than the test kits on a per load basis, explaining their popularity with oil recyclers. Although static headspace testing for volatile organics is a well established technique approved by the EPA, it is typically done either for qualitative identification or quantification of individual volatile organic compounds, imder carefully controlled conditions in the laboratory using gas chromatogr^hy (GC) or gas chromatography/mass spectrometry (GC/MS)^. The applicability of refiigerant leak detectors as either qualitative or quantitative field screening tools for total halogens m used oils by static headspace testing has not been evaluated or approved by EPA nor have the vendors of these detectors provided applications guidance. This work describes an evaluation of the type of electronic leak detector most commonly

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used by oil recyclers. The objective was to determine if such leak detectors are appropriate screening tools for total halogens in used oil. The performance of several models was compared to that of the EPA field method SW-846 Method 9077C and the laboratory methods SW-846 Methods 5050/9056 using formulated samples and commercial products. The ability of this technology to detect all of the halogenated species in used oil and its detection threshold, operating range, accuracy, precision and sensitivity to potential interferences Hkely to be found in used oils (gasoline, water, antifi'eeze) was determined. The effect on results of conditions likely to vary in a field envirormient (temperature, headspace volume, wind and equilibration time) was also evaluated. LEAK DETECTORS The intended use of leak detectors in the HVAC and refiigeration maintenance industries is to identify the presence, location and if possible, intensity of a leak of a refiigerant gas fi-om a sealed system. This is accomplished by moving a probe connected to a test meter in the area of the suspected leak. Refiigerant gas in the air is transported to the detector located in the probe tip by either diffusion or a small air pump. Models based on pump technology are inherently more sensitive than ones based on diffusion. Sensitivities are rated on the basis of the projected weight per year leak rate of the refiigerant being monitored, e.g. 0.5 oz./yr. These probably correspond to ppm levels in ambient air, but detection thresholds in air have not been reported. Because the detectors are not compound-specific, the specific refiigerant gas being monitored must be known to properly interpret the meter output, which may consist of an audible alarm or both the alarm and an illuminated visual Ught emitting diode (LED) display, typically up to 7 LEDs. A survey of the oil recycling industry determined that only leak detectors based on the negative corona discharge principle have been used to screen used oil for total halogens and that these type detwtors have been used for this purpose since 1985. The negative corona discharge type detectors consist of a sensing tip and in most models, an air pump, both located in a flexible probe handle"-"". These are connected to a meter, which contains electronic circuitry for converting the signal from the probe into audible and visual alarms. The sensing tips are composed of an anode and a cathode exposed to ambient air. The application of2000 volts (V) to the electrodes creates a corona or cloud of electrons between them with a known current flow. The electronic circuitry converts this current flow into a proportional voltage potential which is measured and stored for reference when the meter is turned on. Any reduction in the currrat flow results in a decrease in the measured voltage potential. If the potaitial falls below the stored value, the audible and visual alarms are produced. Signals are generated by compounds that remove electrons fix)m the electron cloud, based on the principle of electron affinity. The electron affinities of the halogens are among the greatest of all elements and halogen-containing compounds are among the most easily detected using this technique. However, any compound that can accept electrons &om the corona (e.g., oxygen-containing species), will also generate a measurable signal if present in high enough concentrations.

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Detectors manufactured by TIF Instruments, Inc. (TIF) of Miami, FL are the ones used by oil recyclers. These detectors, (the 5000 series), include the features akeady described (7 LEDs), plus two separate measxirement modes for reporting signals due to chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) and for the newer class of chlorine-free refrigerants, the hydrofluorocarbons (HFCs), which only contain fluorine. Because the response to fluorine is 20 to 100 times less than for chlorine, a separate, more sensitive circuit is used for HFC measurement. However, the user must know which compound is being measured for the signal from either circuit to be meaningful. The next generation of these detectors, which have recently become available, contain a single circuit and provide somewhat greater sensitivity. The XP-1, also known as the Halogen Hawk, is the most advanced of these and can display up to 18 LEDs over 6 levels of sensitivity, each said to be twice as sensitive as the one before it". It is not known if any of these redesigned models are being used by recyclcrs and there are no data available comparing their performance with the 5000 scries. There is controversy about the applicability of these detectors to mom, .ring non refrigerants. TIF reports that they respond to ethylene (500 ppm) and isooctane, but not common halogenated and non halogenated solvents including acetone, benzene, carbon tetrachloride, chlorobenzene, ethanol, gasoline, methylene chloride and perchloroethylene". However, they also report that gasoline leaves a detectable residue that desensitizes the probe tip should it contact a liquid containing gasoUne and that any halogen-containing gas can be detected, including perchloroethylene" ". A vendor for the detectors states that the detectors can be used to determine ethylene in oil to be recycled". STUDY DESIGN Equipment Tested Five leak detectors believed to be representative of those used by oil recyclers were evaluated. Three model 5650 units (audible and visual alarm), one Model 5550 (audible alarm only) and one XP-1 Halogen Hawk were either purchased new or recertified as properly functioning by TIF Instruments. The XP-1 was included because it represents the most advanced and sensitive version of this type detector and provides a more detailed rqjorting of the signal (up to 18 LEDs). For these reasons, it was expected to aid in the analysis and explanation of results using the 5000 series detectors. Two of the 5650 units had been in service for several years and malfimctioned repeatedly, alarming in the absence of known analytes. One of these was clearly less sensitive than the others for unknown reasons. However, after being serviced by the OEM for the second time in 90 days, the performance of both was judged to be acceptable for the purposes of this study. Malfunctions such as these are j^parently conunoi^lace according to the oil recyclers, bringing into question the reliability of the units. Samples were also tested using EPA SW-846 Method 9077C, a quantitative method based on the Clor-D-Tcct Q4000 test kit of the Dexsil Corp. with a range of 200 to 4000 ppm as total halogens, and by EPA SW-846 Methods 5050/9056*".

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Samples Tested A variety of halogenated and nonhalogenated compounds and matrices representative of those encountered in used oil recycling were tested. Samples of virgin engine oil (Western Auto lOW-40) were formulated to contain 0 to 5000 ppm as total halogens of 6 of the regulated halogenated solvents (methylene chloride, chlorobenzene, 1,1,1-trichloroethane, carbon tetrachloride, trichloroethylene and perchloroethylene), chlorinated parafBns from cutting oils and engine oil additives, inorganic chloride, and PCBs, as Aroclor 1242 and Askarel A, a mixture of PCBs and trichlorobenzene sometimes found in transformer oil. PCBs were included because, although limited by regulations to <2 ppm in used oil, high level contamination (>2000 ppm PCBs) from mixing with transformer oil could still be expected to be identified using the 1000 ppm threshold. Samples containing water, antifi^eze, gasoline, alcohols, and acetone were also tested to determine if these common used oil contaminants were detectable and could resuh in false positive classification of the oil. Fuels and neat commercial products (cutting oils and solvents) were also tested to determine their absolute detectability. Commercially available used oil standards certified for chlorine content were also tested. Used engine oils obtained directly bom engine crankcases were tested to determine if contamination due to gasoline resulting from normal use could be detected and result in excessive false positives. Nineteen virgin internal combustion and diesel engine oils from major refiners (Chevron, Mobil, Shell, Quaker State, Motor Craft, Havoline, Castrol, etc.) were tested to determine if the components in virgin oil contribute to any positive results. Samples were tested at least in triplicate and in the case of the 5650 leak detectors, using both the HFC and CFC/HCFC modes. The Halogen Hawk was tested at sensitivity levels 4 and 5 on all samples and at all levels on certain samples. Levels 4 and 5 were determined to provide the most usefiil comparative data vs. the other detectors. Test Conditions Evaluated The EPA methods were performed on all samples without deviation from the methods. A small sample of oil (<0.5 g) was removed Scorn each container and analyzed. Because there is no standard procedure for testing used oil using the leak detectors, a procedure was developed for the purpose of this evaluation. Anecdotal information provided by recyclers suggests tiiat field use practices mvolve either inserting the leak detector probe into the headspace of a tank or drum and noting the response or removing samples and testing them in 4 oz. open top glass jars'*. Recognizing that there are many concerns about sample headspace integrity and stabiUty in vessels open to the atmosphere, an open vessel procedure was employed, since this is what recyclers who remove samples for testing are using and would probably continue to use. Developing closed top vessels in which the probe (the diameter of a pencil) can easily be inserted through the cap and removed was investigated and found to be impractical due to the need to mix samples before testing, which can contaminate the probe through droplets that adhere to the underside of the cap. Use of larger vessels, with narrowa: openings, hke

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8 or 16 oz. Boston round bottles, would limit headspace washout by wind and drafts, but tiiie possibility of probe contamination would still exist. The procedure followed was to test the samples in 4 oz. wide-mouth glass bottles (either 50% or 85% ftill) after equilibration for 12 hours without any mixing and after shaking for a few seconds. These conditions roughly model those encoxmtered in field samples in which the static headspace of a tank or drum is tested or a sample removed and mixed on the spot and the headspace tested. The testing procedure consisted of quickly inserting the probe into the headspace above the sample and recording the signal observed (no. of LEDs, audible alarms). It was not possible to differentiate sound levels with regard to intensity, so the audible alarm responses were recorded as either a yes or a no. Because even sKght drafts in room air appeared to reduce the headspace concentration of some samples, as measured by the number of LEDs recorded, all tests were carried out with the HVAC turned off Outside testing resulted in 50-100% loss of signal, even in relatively Ught winds. Disruption of the headspace by the probe itself was sometimes also noted, and whenever low results believed due to this were obsa-ved, the sample was reanalyzed. Due to the very low pmnp rates (estimated to be <0.1 mL/min), the leak detectors themselves are believed to remove an insignificant amount of the headspace gas due to pumping. Thus, r^eated testing of the same headspace is possible as long as it is not physically diluted by the insertion and removal of the probe. The effect of temperature, a known variable in headspace testing of viscous liqmds', was evaluated by testing samples at 0', 32* and 75-80"F, the laboratory temperature. Previous work suggested a significant decrease in the niunber of LEDs reported for the 5000 series detectors at 45'F compared to room temperature". Since much of the used oil is collected from outside unheated tanks and drums in the northeastern and midwestem U.S., the effect of low ambient temperatures on the headspace concentration of total halogens must be considered in evaluating the apphcability of the leak detectors. Calibration of the detectors to only respond at levels >1000 ppm total halogens by blanking them against a known standard has been reported as have attempts to blank the detectors against oils containing suspected false positive interferences (the oil matrix, gasoline, water)*, but we foimd that none of the detectors can retain a signal firom one discrete sample to the next. The only blanking c£q)ability is that of re-zeroing the detector in a continuum of concentration in ambient air, either by use of a reset button or by turning the detector on in a given atmosphere, so as to more easily track dovm a source of leaking refiigerant. Thus, the only way to relate the detector signal to a concentration in the oil is by direct comparison to a knovm standard. This was the approach followed in this study. RESULTS The results of tests performed on the formulated samples using the EPA methods showed that the recoveries of the spiked analytes were greater than 90% for both the bomb/IC and the test kit methods for the halogenated solvents, chlorinated paraffins, inorganic chloride, and PCBs. No false positives due to non-halogenated solvents, water, ethylene glycol or gasoline were observed nor were any false negatives due to the non-volatile chlorinated

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compounds (paraffins, inorganic chloride, PCBs). The same type performance was achieved on the analyses of commercial products. Results obtained using the 5000 series leak detectors were nearly identical for both the HFC and CFC/HCFC modes. About one third of the virgin oils produced a positive response using the 5550 detector, including the Western Auto oil used as the base for the formulated samples. The Halogen Hawk registered an average of 0.2±0.4 and 1.0±1.0 LEDs, respectively at levels 4 and 5 for the virgin oil vs. 8.0±0.0. and 17.7±0.6 for 500 ppm methylene chloride. Thus, it can be concluded that the virgin oil matrix has Uttle effect on the signal obtained and attempts to account or correct for it are unnecessary. Although all the detectors responded to the volatile halogenated solvents, the sensitivity varied greatly, suggesting that both the volatiUty and the number of chlorine atoms on the molecule contribute to the signal intensity. For example, the maximum no. of LEDs observed for methylene chloride using the 5650 detectors was 3, while nearly 5 were measured for carbon tetrachloride and only 2 for chlorobenzene, the least volatile of the solvents tested. At the sample level closest to the regulatory threshold, 1200 ppm, chlorobenzene was not detected at all. Some of the more highly chlorinated solvents, e.g., carbon tetrachloride, were detected at levels as low as 50 ppm, but the lower limit of detection was generally several hundred ppm in the oil. The precision was generally better than 10% CV for the triplicate analyses, but even so, the occasional zero LED response for a known positive sample would not be considered acceptable for a regulatory test method. The intensity vs. concentration relationship for the most volatile solvents appears logarithmic, with a rapid initial response, which becomes linear or even flat between 1000 and 5000 ppm. (Figures 1 and 2). As noted, although the response spears related to both the compound's vapor pressure and degree of halogenation (Table 1), the relationship is a complex one.

Figure 1 Awrage Response of 5650 Detectors To CUorinatedSfdwiits

* 5

0 1000 2000 3000 4000 5000 6000 Cblorine Concentration (ppn)

— M o t h y l e n e Chtorida

- - » « - - Trichloroolhyleno

111-Trichtoro9than« — Carbon Tetrachloride

l rchloroethyleno Chlorobenzene

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Elgure 2 Hawk Response to Chlorinated Sol wnts

3.5 § 3 d 2.5 1 2 1 1.5 e 1

Z i 0.5 <

0

. - r ^ r ^

^ k -

- 1

4

- • — • "

1000 2000 3000 4000 Clilorine Concentration (ppm)

5000 6000

-Msthylene Chloride - TrichlortJ^ylene

• 111-Trichloroethane • Rsrchloroethylene

- Carbon Tetrachloride - Chlorobenzene

Table 1. EPA Hazardous Waste List Halogenated Solvents and Other Halogenated Substances Regulated in Used Oil In Order of Decreasing Vapor Pressure)"-"

Vapor Splv^nr CA$N9, p.p.;c Pre??UTe, KPa, dichlorodifluoromethane 75-71-8 46.8 6S1 trichloronuno- 75-69-4 24 106

fluoromethane methylene chloride 75-09-2 40 sta l,l,2-trichloro-l,2,2,- 76-13-1 48 44.1 trifluoroethane 1,1,1 -trichloroethane 71-55-6 74 16.5 carbon tetrachloride 56-23-5 76.8 15.2 trichloroethylene 79-01-6 87 1,1.2-thchloroethane 79-00-5 114 3.1 tetrachloroetfaylene 127-18-4 121 1 4

(perchloroethylene) chlorobenzene 3114-55-4 132 1.6 o-dichlorobenzeoe 95-50-1 180 0.18 trichlorobenzencs'' 120-82-1 208-219 17.3 (@90'C) Qtli^TCompoynds C,4-Ci7 chlorinated NA NA' 2 X 10' paraffins

PCBs 1336-36-3 160-300 lO'-lO"'

No. Halogen Atpffis/Mplecul?

6-8 4-5

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1 KPa = 7.501 nim Hg, 0.987 x lO * atm the EPA hazardous waste regulations also apply to any other chlorinated fluorocarbons used in degreasing operations ""CAS no. given is for 1,2,4-trichlorobenzene 'these compounds decompose at >300*C, with the release of HCl NA « not available

The response relationship shown in Figure 2 for the Halogen Hawk is based on the average response of the meter, measured at all sensitivity settings and normalized to an equivalent level 1 reading. The quantitative relationship between the LED response of the Halogen Hawk to the 5650 meters has also not been established. Thus, its resuUs should only be considered as assisting in explaining the qualitative differences in response of different compounds, especially the fact that the saisitivities were in the same order as for the 5650 detectors. Some recyclers claim that the intensity vs. concentration relationship allows the use of 3 LEDs as the cutoff for rejecting loads, since most of the aliphatic halogenated solvents will produce a reading of 3 LEDs at halogen levels greater than 1000 ppm. However, not every detector evaluated in this study produced 3 LEDs for samples containing 1200 ppm of aliphatic halogenated solvents and chlorobenzene. Oils containing 1200ppm chlorine levels due to solvents even less volatile, e.g., o-dichlorobenzene, would not be expected to meet this criterion either. The detectors were unable to detect the non-volatile halogenated compounds (parafBns, inorganic chloride, PCBs) even at levels as high as 1% PCBs as Aroclor 1242 or 3% chlorinated paraffins (as chlorine). The detectors were also generally unable to detect relatively non-volatile oxgen-containmg species like glycols and water, but did exhibit strong sensitivity to volatile oxygraiated solvents like methyl ethyl ketone and acetone, due to the electron affinity of the oxygen. Virgin oils spiked with gasoline at levels typically found in used oil not exposed to halogenated solvents (1000 ppm) and used oils obtained torn gasoline engines produced signal intensities of aroimd 1 LED for the 5650 detectors and equivalent to the signals observed for 1200 ppm methylene chloride using the Halogen Hawk. Little difference was observed between results fiwm samples equilibrated 12 hours and those freshly shaken. However, once the headspace was removed, more than 30 minutes was required to reestabUsh the equilibrium level without mixing. Since the equiUbrium status of bulk containers in the field cannot be known in advance, a direct analysis of the headspace is not appropriate and a sample must be collected and mixed before the headspace is analyzed. The volume of headspace in the bottles did not significantly influence the results (results obtained fiom 50% fiill jars were about the same as those obtained torn 85% fiill bottles). A reduction in temperature torn 75* to 32F did result in a decrease in the signal for most of

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the halogenated solvents, reducmg it to zero for methylene chloride and perchloroethylene at 1200 ppm for one of the detectors. At 0"F, the signal from all of the 5650 detectors was reduced to zero for perchloroethylene at 1200 ppm and for chlorobenzene at 5000 ppm, and for one detector the signal was also reduced to zero for methylene chloride at 5000 ppm. The effect of temperature and headspace volume on the results can be explained by the theory of headspace testing. The basis for headspace or vapor equilibration analysis is that the analyte partitions between two phases (in this case oil and air) at a constant ratio once equilibrium between these phases has been attained. The factors affecting the air level include the analyte's solubility in the oil and the vapor pressure of the pure confound at a given temperature". For viscous liquids hke oils, in which the analyte is more or less miscible as in the case of halogenated organics, the organics prefers to stay in the oil, so that the volume of the headspace relative to the oil layer is largely irrelevant to the headspace concentration of analytes". By raising the temperature, the headspace concentration of volatile organics can be iiKreased and, likewise, by lowering the temperature, the headspace concentration can be decreased. However, largely nonvolatile chemicals Uke PCBs, chlorinated parafBns and salts will not partition into the headspace to any detectable degree, even at elevated temperatures, rendering their detection using headspace techniques impossible. CONCLUSIONS AND RECOMMENDATIONS Although refrigerant leak detectors are clearly sensitive to some of the volatile halogenated solvents, from a regulatory standpoint, their inability to detect the nonvolatile halogens and chlorobenzene at the regulatory threshold of 1000 ppm, their susceptibility to false negatives due to low temperatures, and vapor losses during field testing, make them unsuitable as a screening tool for total halogens in used oil. Limiting the Ust of compounds to be screened to the most volatile solvents is unacceptable, since the regulations are intended to limit the total halogens that enter the used oil management system. It is likely that the use of these types of leak detectors to certify loads of used oil as meeting the halogen limit have actually done the opposite and allowed greater contamination than EPA or the recyclers intended. So, although recyclers cannot be prohibited from using the leak detectors, they must still provide EPA with ind^endent knowledge based on the history of the oil's use or results from testing using EPA or ASTM methods in order to meet the regulatory requirements. As noted at the beginning, recyclers claim that the cost of the test kits and the time it takes to perform the tests are prohibitively expensive given the dynamic nature of the used oil recycling industry (many locations, many discrete containers of used oil, which must be collected and processed daily). EPA also assumed that the cost of reqmred testing of all loads from every generator before they are collected and enter the used oil management system would force recyclers out of business and discourage recycling by used oil generators. Thus, they did not require testing, but still insisted on a certification of the oil's quality with respect to the regulatory limits for total halogens. This lead to the recycler's use of the leak detectors and the problems described in this paper.

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One way to make certain that used oil cleanliness is ensured without disrupting the present commercial market system is by offering tax credits to qualified recyclers and generators, hi return for performing testing of the used oil by s^proved EPA or ASTM methods instead of by the leak detectors or not at all as is also common, they would receive a dollar per dollar tax credit for testing costs, including labor and administrative costs. EPA and states would then have the option of inspecting the testing records kept by the mdtistry to ensure that compliance is occurring and the oil quality is within the limits for total halogens. REFERENCES 1. Code of Federal Regulations (40 CFR), Part 279, Standards for the Management

of Used Oil, published by the OflBce of the Federal Register, 1995. 2. Federal Register, Hazardous Waste Management System; Burning of Waste Fuel

and Used Oil Fuel in Boilers and Industrial Furnaces, Vol. 50, No. 230, Friday Nov. 29, 1985, pp. 49164-49211.

3. Gaskill, A., Jr., E.D. Estes, D.L. Hardison, L.E. Myers and B. Lesnik. Vahdation of Analytical Methods for Determining Total Chlorine in Used Oils and Oil Fuels. Presented at the Fourth Aimual U.S. EPA Syn^osium on SoUd Waste Testing and Quality Assurance, Washington, D.C., July 11-15,1988.

4. Gaskill, A., Jr., E.D. Estes, D.L. Hardison, L.E. Myers and W.M. Yeager. Validation of Test Kit Methods for Determining Total Chlorine in Used Oils and Oil Fuels. Presented at the Fifth Annual U.S. EPA Symposium on SoUd Waste Testing and Quality Assurance, Washington, D.C., July 24-28,1989.

5. Gaskill, A., Jr., E.D. Estes, D.L. Hardison and P.H. Friedman. Development and Evaluation of Analytical Techniques for Total Chlorine in Used Oils and Oil Fuels. In: Symposium on Waste Testing and Quality Assurance: 2nd Volume, ASTM STP1062, David Friedman, editor, American Society for Testing and Materials, Philadelphia, 1989.

6. U.S. EPA, Test Methods for Evaluating SoUd Waste, Physical/Chemical Methods, (SW-846), Third Edition, Office of SoUd Waste, Update n, September 1994.

7. ASTM D5384-96, Standard Test Methods for Chlorine in Used Petroleum Products (Field Test Kit Method), American Society for Testing and Mataials, West Conshohocken, PA.

8. B. Kolb and L.S. Ettre, Static Headspace-Gas Chromatography Theory and Practice, Wiley-VCH, Inc., New York, 1997.

9. EPA Method D- l-VOA: Quick Turnaround Method for Contract Laboratory Practice (CLP): Static Headspace Method for Volatile Organic Analytes (VOA)

in Soil/Sediments Employing an Automated Headspace Sampler (November 1989).

10. Omega Engineering, Spec. Sheet, Halogen Leak Detectors, http:/Avww.omnicontrols.com, (accessed November 1998).

11. Automatic Halogen HFOCFC/HCFC Leak Detectors Owners Manual, TIF Instruments, Inc., Miami, FL, 1998.

12. Lannes Whitelock, TIF Instruments to Wendy Yoimg, Dexsil Corp., February 27, 1998.

13. TIF XP-l Halogen Hawk Automatic Halogen Leak Detector, Owner's Manual 14. Omega Engineering, GHH-5050, GHH-5550 and GHH-5650 Halogen Leak

Detectors Operator's Manual, M1701/0993 15. Dexsil Corp., Hamden, CT. 16. Dennis Brinkman, Safety-Kleen, personal communication, March, 1999. 17. D.R. Lide, CRC Handbook of Chemistry and Physics, 75th Edition, 1994, CRC

Press, Inc., Boca Raton, FL. 18. M.E. Meek and M.J. Giddings, Environmental Health Criteria. 128

Chlorobenzenes Other Than Hexachlorobenzene, WHO, Geneva, 1991. 19. K. Kenne and U.G. Ahlborg, Environmental Health Criteria, 181. Chlorinated

Paraffins, WHO, Geneva, 1996. 20. M.D. Erickson, Analytical Chemistry of PCBs, Butterworth Publishers, Boston,

1986. 21. R.L. Grob, Modem Practice of Gas Chromatoghaphy, John Wiley and Sons, Inc.,

New York, 1995. Key words: chlorinated solvents, halogens, headspace, leak detectors, test kits, used oil

Figare 1 Average Respooce of 5650 Detectors To Chlorinated Solvents

5 T , 1 . , ,

6000 Clilorine Concentration (ppm)

—•—Methylene Chloride —•—111-Trtchloroethane — * — C a r t » n Tetrachloride

-•K-Trichloroethylene —K—Perchloroelhylene — C h k x o b e n z a n e

Figure! Hawk Response to Chlorinated Solvents