Alcohol Limits and Public Safety.

On May 14, 2013, the National Transportation Safety Board (NTSB) recommended lowering the legal blood-alcohol limit to 0.05 g/dL for motor vehicle operators in the United States, in an effort to reduce the risk of injuries and deaths caused by a driver's alcohol impairment (NTSB/SR-13/01). This recommendation has prompted other organizations and agencies, including the National Safety Council, to evaluate and consider supporting this action. In order to determine the scientific and legal feasibility and advisability of lowering or establishing 0.05 per se laws, we examined 554 alcohol-related publications. Risk factors, instrument reliability, law enforcement, and adjudication issues were considered in this overview of the literature. The extensive scientific literature reviewed provides ample support for lowering the operation of motor vehicle alcohol limits to 0.05, and for supporting the NTSB recommendations. Research clearly demonstrates that impairment begins at very low concentrations, well below the recommended NTSB limit, and increases with concentration. Lowering the limit to 0.05 will save many lives and prevent injuries. Breath, blood, and saliva samples have proved to be accurate and reliable specimens for legal acceptability in a court of law.

A Brief History of the Indiana University Center for Studies of Law in Action and the Robert F. Borkenstein Course on Alcohol and High Safety.

For the past 50 years, the Indiana University Robert F. Borkenstein Course on Alcohol and Highway Safety, founded by Professor Robert F. Borkenstein in 1958, has made a unique and lasting contribution to that subject by providing expert-level short-course instruction to more than 5,000 registrants from North America and many international locations. Since 1971, the course has been sponsored and presented by the Indiana University Center for Studies of Law in Action, also established by Prof. Borkenstein. The center has been involved in three primary missions in the field of alcohol, drugs, and traffic safety: (a) To carry out and facilitate research; (b) to present short courses and engage in other educational activities; and (c) to serve as a repository for information, available to educators, practitioners, and researchers. The pervasive and cumulative accomplishments of the Robert F. Borkenstein Course and the Indiana University Center for Studies of Law in Action were recognized in August 2007 by conferral of the Widmark Institutional Award by the International Council on Alcohol, Drugs, and Traffic Safety - the highest international honor in that field for outstanding contributions by a nongovernmental organization. This article recounts the history and accomplishments of the course and the center, as a tribute to both, and to Prof. Borkenstein, and to illuminate the path that led to the 16th ICADTS Widmark Institutional Award.

Measurement of low breath-alcohol concentrations: laboratory studies and field experience.

Recent federal rules and traffic law changes impose breath-alcohol thresholds of 0.02 and 0.04 g/210 L upon some classes of motor vehicle operators, such as juveniles and commercial vehicle operators. In federally regulated alcohol testing in the workplace, removal of covered workers from safety-sensitive duties, and other adverse actions, also occur at breath-alcohol concentrations (BrACs) of 0.02 and 0.04 g/210 L. We therefore studied performance of vapor-alcohol and breath-alcohol measurement at low alcohol concentrations in the laboratory and in the field, with current-generation evidential analyzers. We report here chiefly our field experience with evidential breath-alcohol testing of drinking drivers on paired breath samples using 62 Intoxilyzer 5000-D analyzers, for BrACs of 0-0.059 g/210 L. The data from 62 law enforcement breath-alcohol testing sites were collected and pooled, with BrACs recorded to three decimal places, and otherwise carried out under the standard Oklahoma evidential breath-alcohol testing protocol. For 2105 pooled simulator control tests at 0.06-0.13 g/210 L the mean +/- SD of the differences between target and result were -0.001 +/- 0.0035 g/210 L and 0.003 +/- 0.0023 g/210 L for signed and absolute differences, respectively (spans -0.016-0.010, 0.000-0.016). For 2078 paired duplicate breath-alcohol measurements with the Intoxilyzer 5000-D, the mean +/- SD difference (BrAC1-BrAC2) were 0.002 +/- 0.0026 (span 0-0.020 g/210 L). Variability of breath-alcohol measurements was related inversely to the alcohol concentration. Ninety-nine percent prediction limits for paired BrAC measurements correspond to a 0.020 g/210 L maximum absolute difference, meeting the NSC/CAOD recommendation that paired breath-alcohol analysis results within 0.02 g/210 L shall be deemed to be in acceptable agreement. We conclude that the field system for breath-alcohol analysis studied by us can and does perform reliably and accurately at low BrACs.

The stability of ethanol in human whole blood controls: an interlaboratory evaluation.

Sterile whole human blood control materials were commercially prepared in batches containing anticoagulants and preservatives and approximately 90, 150, and 230 mg/dL ethanol with and without 0.3% (w/v) sodium azide. Aliquots in sealed vials were stored by the manufacturer at 2-8 degrees C until shipped monthly to three academic toxicology laboratories that analyzed them in duplicate by gas chromatographic headspace methods at monthly intervals for one year. The resulting data were pooled, and grand mean values were statistically analyzed to determine the respective alcohol stability in these azide-free and azide-containing blood samples. Azide-containing blood samples showed no alcohol losses during the 1-year period. Azide-free blood containing 1.0% (w/v) sodium fluoride and anticoagulants had small alcohol decreases over time, the total losses after one year being less than 5% of the original alcohol concentrations. The initial alcohol concentration of approximately 40 mg/dL also did not change during storage of additional samples of azide-free blood for one month at 4 degrees C. We concluded that addition of sodium azide to performance-test and control blood specimens for alcohol analysis is unnecessary and unwarranted and that alcohol losses in such blood samples can be minimized by simple appropriate treatments and conditions.

Vapor-alcohol control tests with compressed ethanol-gas mixtures: scientific basis and actual performance.

Commercial compressed vapor-alcohol mixtures ("dry gas") were evaluated to ascertain their suitability for control tests in breath-alcohol analysis. Dry gas control tests were conducted at nominal vapor-alcohol concentrations (VACs) of 0.045, 0.085, and 0.105 g/210 L (n = 50 at each VAC) with Alcotest 7110 MK III and Intoxilyzer 1400 evidential breath-alcohol testers. The measurement results were analyzed by standard statistical methods, and their correlation with certified dry gas VAC target values was examined. Also measured and examined statistically were the VACs of National Institute of Standards and Technology-traceable Research Gas mixtures (dry gas) ethanol standards at 97.8 and 198 ppm (n = 30-50 at each VAC). With the Alcotest 7110 MK III programmed to report VACs normalized to standard atmospheric pressure at 760 torr and the intoxilyzer 1400 programmed to report VACs at ambient atmospheric pressure, the predicted effects of ambient atmospheric pressure were confirmed experimentally. We developed and validated the following conversion factor for VAC units at 34 degrees C and 760 torr: ppm/2605 = g/210 L and g/210 L x 2605 = ppm. We found that the dry gas vapor-alcohol control samples conformed to established formal specifications and concluded that they compared favorably with simulator effluents for control tests of breath-alcohol analyzers, which are capable of adjusting VAC results for ambient atmospheric pressure.

Quality assurance in breath-alcohol analysis.

Evidential breath-alcohol testing requires an adequate quality assurance (QA) program to safeguard the testing process and validate its results. A comprehensive QA program covers (a) test subject preparation and participation; (b) the analysis process; (c) test result reporting and records; (d) proficiency testing, inspections, and evaluations; and (e) facilities and personnel aspects. Particularly important are the following necessary scientific safeguards as components of quality control: (a) a pretest deprivation-observation period of at least 15 minutes; (b) blank tests immediately preceding each breath-collection step; (c) analysis of at least duplicate breath specimens; and (d) a control test accompanying every subject test. These safeguards have withstood adversarial challenges in the judicial system for more than 30 years.

Field performance of current generation breath-alcohol simulators.

The between-run accuracy and reproducibility of vapor-alcohol control tests associated with quantitative evidential breath-alcohol testing in the field were evaluated. Control samples were generated at six separate sites with 34 degrees C TOXITEST II breath-alcohol simulators and analyzed by infrared spectrometry with Model 5000-D intoxilyzers in the recirculation mode. Control test results at target alcohol concentrations of 0.060, 0.080, 0.090, 0.100, 0.110, and 0.120 g/210 L (n = 779) were combined and analyzed by standard statistical methods. Results were correlated with target values, and the signed and absolute differences were calculated and analyzed. Data treatment included ANOVA, linear regression analysis, t statistics, and relative and cumulative frequency distributions of the differences. We found the performance of these current generation simulators in the field to be similarly satisfactory to that obtained in our laboratory evaluation. We further found that vapor-alcohol control samples generated with these devices conformed to established formal requirements and that they can serve as an effective quality assurance measure in evidential breath-alcohol analysis.

Evaluation of commercial breath-alcohol simulators: further studies.

Exemplars of current commercial breath-alcohol simulators were studied to ascertain their suitability for control tests and as calibrators in breath-alcohol analysis. Temperature, effluent volumes and pressures, effluent-alcohol concentration, and alcohol depletion were measured for simulators coupled with various current alcohol analyzers. Effluent recirculation was found to extend the number of acceptable control test cycles by 3.2 x over nonrecirculation. We found substantial improvements in current commercial simulators and in their performance over those evaluated in 1979.

Absorption, distribution and elimination of alcohol: highway safety aspects.

Key aspects of the pharmacokinetics of alcohol are highly relevant to highway safety. Of particular pertinence are the partition of alcohol between various body tissues and fluids and the resulting alcohol concentration ratios for blood: breath and other body fluids, as well as the irregularity and short-term fluctuations of the blood and breath alcohol curves. Most alcohol pharmacokinetics parameters are subject to wide intersubject variability, as exemplified by peak blood alcohol concentrations reached on ingestion of identical weight-adjusted doses, time to peak after end of drinking and the rate of alcohol elimination from the blood. This great biological intersubject variability, when combined with sex-, age- and time-related differences, makes the blood alcohol information in widely distributed alcohol consumption nomograms and tables based on mean data inappropriate as a guide for the drinking behavior of individuals. Although there is good statistical correlation between the alcohol concentration of different body tissues and fluids in the fully postabsorptive state, wide individual variations from the population mean alcohol partition values exist. It is often impossible to determine whether the postabsorptive state has been reached at any given time. Those factors make it impossible or infeasible to convert the alcohol concentration of breath or urine to the simultaneous blood alcohol concentration with forensically acceptable certainty, especially under per se or absolute alcohol concentration laws. Inclusion of breath alcohol concentrations in drinking-driving statutes, as definitions or per se offense elements, makes unnecessary the conversion of breath alcohol analysis results into equivalent blood alcohol concentrations. Urine alcohol concentrations are inadequately correlated with blood alcohol concentrations or with driver impairment, and analysis of bladder urine is, therefore, inappropriate in traffic law enforcement. Significantly large sex-related differences in pharmacokinetic parameters have been demonstrated (e.g., in peak blood alcohol concentrations for weight-adjusted doses). The effects of age and time of day have been less extensively studies and are less clear. Breath and blood alcohol time curves are subject to short-term fluctuations from the trend line and other irregularities, and often do not follow the typical Widmark pattern. From the existing information on pharmacokinetics of alcohol and the characteristics and variability of blood and breath alcohol versus time curves, the following conclusions can be reached.(ABSTRACT TRUNCATED AT 400 WORDS)

Response of breath-alcohol analyzers to acetone: further studies.

Seven quantitative evidential breath-alcohol analyzers in three categories of analytical principle were tested for response to dynamically generated vapor acetone concentrations of 3, 100, 150, 350, and 600 micrograms/L and to alcohol-acetone vapor mixtures of 0.10 g alcohol/210 L and 350 or 600 micrograms acetone/L. No significant interference by acetone at any of these concentrations was found in four of the tested instruments. Two devices employing single wavelength infrared spectrometry displayed no unacceptable responses to acetone in concentrations to 350 micrograms/L, and one device employing solid-state (Taguchi) sensing was found to be significantly sensitive to acetone at the two highest tested concentrations. Except for the latter device, response to acetone of those instruments tested is not considered to be a significant problem in breath-alcohol analysis for traffic law enforcement or other purposes.

Response of breath-alcohol analyzers to acetone.

Quantitative evidential breath-alcohol analyzers and screening testers in each of the five current categories of analytical principle were examined for response to dynamically-generated acetone vapor concentrations of 3, 100, 150, 350, and 600 micrograms/210 Liters. Nine of the 13 instruments tested were unaffected by acetone at any of these concentrations; three solid-state (Taguchi) sensing devices and one device employing single-wavelength infrared spectrometry displayed responses to acetone at the two highest tested concentrations. In view of a breath-acetone literature survey for ambulatory subjects and other considerations, response of the tested devices to acetone is not considered to be a significant problem in breath-alcohol analysis for traffic law enforcement purposes.

Variability in blood alcohol concentrations. Implications for estimating individual results.

In a carefully controlled drinking situation there was great individual variation in peak blood alcohol concentrations (BACS) for given doses of alcohol. Alcohol nomograms and tables based on average results from such studies could be misleading since they could frequently result in serious underestimates or overestimates of peak BACS.

Alcohol analysis of stored whole-breath samples by automated gas chromatography.

A new method was developed to apply the advantages of automated gas chromatographic headspace analysis to delayed measurement of alcohol in whole breath (W-B). End-expiratory breath and vapor-alcohol samples were collected in sealed, heated 22-mL glass vials, stored for 0-15 days, and thereafter analyzed for alcohol by automated GC with aqueous calibrators without further sample preparation. The results were compared with those of direct alcohol determinations in closely adjacent breath samples by IR absorptiometry with an Intoxilyzer. The mean difference between 389 paired-sample breath-alcohol concentrations thus determined was close to zero; the correlation coefficient for linear regression of these results plus corresponding blanks was R=0.989. The new method is practical and reliable for law enforcement, clinical, and research applications of delayed breath-alcohol analysis.

Alcohol determination in the clinical laboratory.

Four methods for blood-alcohol analysis--gas chromatography, enzymatic oxidation with alcohol dehydrogenase, chemical oxidation with acid dichromate, and osmometry--are briefly reviewed from the point of view of the clinical laboratory. Advantages and limitations of these methods are discussed, and their key features are tabulated. The correlation of the results of blood-alcohol analyses with stages of alcoholic influence and their corresponding signs and symptoms is presented in tabular form.