Breath Testing Instruments. The Toxicologist shall approve all instruments to be used in the State for the purpose of testing breath for alcohol content pursuant to Courts and Judicial Proceedings Article, §§10-302 and 10-304, Annotated Code of Maryland. An agency shall only use an instrument that has been approved by the Toxicologist. An individual may receive a copy of the list of the manufacturers and models of currently approved instruments from the Department of State Police Forensic Sciences Division at no charge. Certification of Approval of Instruments. The Toxicologist shall certify approval of each instrument before it is used in the State. At the time of approval by the Toxicologist, the instrument shall be on the most recently updated Conforming Products List of Evidential Breath Alcohol Measurement Devices published in the Federal Register by the National Highway Traffic Safety Administration of the Department of Transportation. On at least an annual basis, the Toxicologist or their representative shall recertify approval of each instrument. Following successful testing, an instrument that is repaired by a certified breath test maintenance technician may be returned to service without the recertification of approval by the Toxicologist. Inspection. Approved equipment and related records shall be available for inspection by the Toxicologist or representative at all times. Validation Tests. The Toxicologist shall approve the alcohol reference solution or alcohol gas standard to be used as validation tests. Validation tests shall be performed contemporaneously with each evidentiary breath test using an approved alcohol reference solution or alcohol gas standard. Initial Certification of Instrument Approval. Precision and Accuracy Testing. Vapor containing 0.020 gram/210 liters, 0.040 gram/210 liters, 0.080 gram/210 liters, and 0.160 gram/210 liters ethanol concentrations shall be introduced through the breath tube of the instrument. Each concentration shall be repeated four times. As an indication of precision, the combined average standard deviation shall be not greater than 0.0042 gram/210 liters. As an indication of accuracy, systematic variations at each ethanol concentration will be calculated and shall be not more than 5 percent or 0.005 gram/210 liters, whichever is greater. Any instruments not meeting the precision and accuracy requirements may not be approved. Acetone Detection Testing. Vapor containing 0.020 gram/210 liters ethanol and 100 microliters of acetone per 500 milliliters solution shall be introduced through the breath tube of the instrument. Each concentration shall be repeated four times. The instrument shall read between 0.015 and 0.025 gram/210 liters. An instrument not meeting the requirement for acetone detection may not be approved. Blank Testing. Four samples of vapor containing no ethanol or other solvents shall be introduced through the breath tube of the instrument. No reading shall exceed 0.005 gram/210 liters vapor. An instrument not meeting the blank detection requirement may not be approved. If conditions outlined in §E(1) — (3) of this regulation are met: The instrument shall be approved; and The Toxicologist shall issue a letter certifying instrument approval. Periodic Recertification of Approval. Instrument approval shall be recertified at least annually. The Toxicologist shall issue a letter recertifying instrument approval. Evidentiary Breath Test Method. For at least 20 minutes before a breath sample is taken, an individual may not: Eat or drink; Have any foreign substance in the individual’s mouth or respiratory tract; or Smoke. The individual shall be observed and mouth checked. Observation of the individual shall be performed by: A breath test operator; Other uniformed or civilian law enforcement personnel; or Any combination of a breath test operator and uniformed or civilian law enforcement personnel. The testing procedure shall begin with a blank test to ensure that no alcohol is present in the breath path of the breath testing instrument. A validation test shall be run before the individual begins the testing process. If the breath testing instrument fails to obtain a reading plus or minus 10 percent of the stated alcohol concentration on the validation test, then the subject test shall be discontinued. The individual shall be instructed to take a breath and then deliver a breath sample into the instrument by blowing into the mouthpiece and breath tube until instructed to stop. After each subject breath sample, a blank check shall be performed to ensure that no alcohol is present in the breath path. Two breath samples shall be collected and analyzed by the breath testing instrument. A third breath sample shall be collected only if the absolute difference between the results of the first and second samples exceeds 0.020 gram/210 liters. A validation test of known alcohol concentration shall be run after the individual has given the required number of breath samples. If the instrument fails to obtain a reading plus or minus 10 percent of the stated concentration on the validation test, then the subject test is invalid. The lower of the two or lowest of the three results of the subject test shall be truncated to the second decimal place and reported as the result of the breath test.