EPA regulations (40 CFR Part 279) as well as certain state regulations, set limits for the levelrnof total halogens in used oil to be recycled into new oil or burned as fuel. This is done tornreduce the emissions of hazardous chlorinated solvents and their by-products, includingrnhydrochloric acid. Although EPA and ASTM field methods developed specifically forrnmeasuring the total halogen content are available, for cost reasons, many oil recyclers usernhand-held refrigerant leak detectors to screen the oil by measuring the headspace above thernoil and using this measurement to estimate the oil phase concentration. Since the regulationsrndo not require that testing be performed, only a certification of the quality of the oil, whichrnmay be based on process or other knowledge, any test method may also be used.rnThe results of an evaluation of the effectiveness of leak detectors in screening used oil forrntotal halogens are presented. In comparison with EPA laboratory and field methods, the leakrndetectors were unable to detect halogens in oils contaminated with low volatility halogenatedrnspecies such as those found in cutting oils and PCBs, even at percent levels. The leakrndetectors also produced an excessive number of false negative responses for volatilernhalogenated species in testing at low temperatures (0-32F) and under windy conditions likelyrnto be found in field situations. Many false positives were also found due to gasoline andrnoxygenated solvents fkequently found in used oil such as acetone and MEK. Because thernleak detectors are an unreliable tool for screening used oil, the recyclers should use the EPArnor ASTM methods. Recommendations are given for creating financial incentives tornencourage recyclers to switch to the EPA methods.
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