Three defendants who were charged with driving while intoxicated challenged the admission of BAC Verifier DataMaster II (DataMaster) breath-alcohol test results. The Seattle Municipal Court suppressed the breath test results in all three cases, holding that the information recorded on the breath test documents was insufficient to determine whether there was compliance with Washington Administrative Code (WAC) regulations. We hold that the breath test documents in these cases constitute prima facie evidence that the City of Seattle complied with former WAC 448-13-040 (1999) and thus satisfied the foundational requirements for admissibility of those documents at trial. Accordingly, we reverse the trial court’s suppression order and remand for further proceedings.
FACTS
On December 19, 2000, Fawn Allison was arrested for driving under the influence. The arresting officer, a certified operator of the DataMaster, conducted a breath test. Following the test, the DataMaster printed test result documents that showed Allison’s blood alcohol level was above the legal limit. Allison was charged with driving while intoxicated. She moved to suppress the breath test results. The trial court consolidated her case with the others involved here. At the suppression hearing, the defendants offered transcripts of proceedings held in other jurisdictions involving accuracy of the thermometers used to measure the temperature of the simulator solution in the DataMaster breath testing machines. It is undisputed that the thermometers used in the DataMaster have a built-in variance of at least +/- 0.1 centigrade. In each case, the parties stipulated that the breath alcohol tests were properly ad*79ministered, that the operators who performed the breath tests observed that the DataMaster thermometer was within 0.2 degrees of 34 degrees centigrade, and that the results indicated blood alcohol levels above the legal limit.
Based on variances in the thermometers, the defendants argued that it is possible to have a reading that indicates the temperature of the simulator solution is within the range of 34 degrees +/- 0.2 degrees centigrade as required by former WAC 448-13-040 when the temperature is actually outside that range. They contended that without a recording of the actual temperature reading on the thermometer, which could be adjusted according to the known variance, it is impossible to establish whether the temperature is within the range set forth in former WAC 448-13--040.
The trial court agreed, reasoning that because the breath test documents do not record an actual temperature reading, and thermometers have built-in variances in accuracy, it is impossible for the city to establish a prima facie showing that the breath test documents meet the requirements of former WAC 448-13-040 and, therefore, can never establish the foundation necessary for admissibility. The trial court suppressed the breath test results. The city appealed and this court granted direct review.
DISCUSSION
The foundational requirements for admissibility of breath test results were first established in State v. Baker, 56 Wn.2d 846, 852, 355 P.2d 806 (1960). In order to satisfy its initial burden to establish foundation, the prosecution must show that (1) the machine was properly checked and in proper working order at the time of the test, (2) the chemicals used were of the correct kind and proportion, (3) the subject had nothing in his mouth at the time of the test, and (4) the test was given by a qualified operator and in the proper manner. Id. at 852. Compliance with approved *80breath test procedures is a condition precedent to admission of the test results. Id. Once the foundational requirements are established and the test results are admitted, a defendant may then attack the test results in a particular case by introducing evidence refuting the accuracy and reliability of the test reading. State v. Straka, 116 Wn.2d 859, 875, 810 P.2d 888 (1991).
When the DataMaster replaced the Breathalyzer machine, a similar set of foundational requirements was adopted, ultimately codified in chapter 448-12 WAC, the precursor to the current WAC regulations in chapter 448-13 WAC. The new machine, and its supporting protocols, was challenged and upheld in State v. Ford, 110 Wn.2d 827, 755 P.2d 806 (1988) and Straka, 116 Wn.2d 859.
The state toxicologist has the delegated authority to designate proper methods for performing the analysis of a person’s blood or breath. RCW 46.61.506(3). In Ford, this court observed that “the Legislature has mandated that the analysis of breath or blood is valid if it is performed ‘according to methods approved by the state toxicologist’.” Ford, 110 Wn.2d at 833 (quoting RCW 46.61.506(3)). “When the protocols . .. and existing Code provisions are followed, there is sufficient assurance of accuracy and reliability of the test results to allow for general admissibility of test results.” Straka, 116 Wn.2d at 870.
The relevant procedures are found in several WAC provisions relating to the use and proper functioning of the DataMaster equipment. Former WAC 448-13-040 provides in part:
The temperature of the solution in the simulator prior to the start of the test must be thirty-four degrees centigrade plus or minus 0.2 degrees centigrade. . . . The results of the test will be provided in the form of a printout on a breath test document.
The issue is whether the breath test documents printed by the DataMaster in these cases, which read “SIM TEMP 34c +/- .2c: YES”, are sufficient to establish a foundation for admissibility of the test results under former WAC 448-13-*81-040. The defendants’ primary argument is that use of the word “be” in the WAC requires the city to prove the actual temperature of the simulator solution.
The city argues that the WAC requires the operator to determine only whether the temperature reading on the DataMaster machine is within the prescribed range and that evidence of thermometer variances bears upon the reliability of the test results in a particular case, and goes to weight, not admissibility of the evidence. Accordingly, the city argues that the test results were improperly suppressed.
The meaning of a statute is a question of law and review is de novo. State v. Breazeale, 144 Wn.2d 829, 837, 31 P.3d 1155 (2001); State v. J.M., 144 Wn.2d 472, 480, 28 P.3d 720 (2001). Rules of statutory construction apply to administrative rules and regulations. State v. Burke, 92 Wn.2d 474, 478, 598 P.2d 395 (1979). If a rule’s meaning is plain on its face, then the court must give effect to that plain meaning. J.M., 144 Wn.2d at 480. “Under the ‘plain meaning’ rule, examination of the statute in which the provision at issue is found, as well as related statutes or other provisions of the same act in which the provision is found, is appropriate as part of the determination whether a plain meaning can be ascertained.” Dep’t of Ecology v. Campbell & Gwinn, L.L.C., 146 Wn.2d 1, 10, 43 P.3d 4 (2002); C.J.C. v. Corp. of the Catholic Bishop of Yakima, 138 Wn.2d 699, 708-09, 985 P.2d 262 (1999). A term in a regulation should not be read in isolation but rather within the context of the regulatory and statutory scheme as a whole. ITT Rayonier, Inc. v. Dalman, 122 Wn.2d 801, 807, 863 P.2d 64 (1993). The court should not construe a regulation in a manner that is strained or leads to absurd results. Burke, 92 Wn.2d at 478.
WAC 448-13-010 articulates the reasons for the rules governing breath testing: (1) to inform “ ‘the public of the administrative aspects of the state’s breath alcohol test program’ ” and (2) to practice those principles accepted in the scientific community. Walk v. Dep’t of Licensing, 95 Wn. *82App. 653, 657, 976 P.2d 185 (1999) (quoting WAC 448-13--010). WAC 448-13-060 provides, in part, that:
A [breath] test shall be a valid test and so certified, if the requirements of WAC 448-13-040, 448-13-050 and 448-13-055 are met, and in addition the following criteria for precision and accuracy, as determined solely from the breath test document, are met:
If these criteria are met, then these and no other factors are necessary to indicate the proper working order of the instrument, and so certify it, at the time of the breath test.
(Emphasis added.)
Taken together, the intent of these two rules is to prescribe a method for administering a breath test that accords with principles accepted in the scientific community and, when followed, produces a valid test as evidenced by a breath test document. Former WAC 448-13-040 sets forth the particulars of the method selected by the toxicologist for administering the breath test on the DataMaster. In the first sentence, the rule provides that “[t]he following method for performing a breath test is approved by the state toxicologist pursuant to WAC 448-13-130.” Former WAC 448-13-040. The rule then lists several steps that an operator must follow in administering the DataMaster test. First, the operator must determine that the person tested does not vomit, smoke, or consume food or drink for at least 15 minutes prior to the test. At the beginning of the waiting period, the operator must examine the subject’s mouth to ensure that it contains no foreign substances, including jewelry. Next, the rule provides that, prior to the start of the test, the temperature of the simulator solution must be within the prescribed range. It then directs that at least two valid breath samples must be provided by the subject. Finally, the rule directs that the results of the test must be provided in the form of a printout on a breath test document.
Read in context, the language at issue in former WAC 448-13-040 is a directive to the DataMaster operator to *83observe whether the temperature of the simulator solution is 34 degrees centigrade plus or minus 0.2 degrees centigrade. If the thermometer registers a temperature within that range, the operator may obtain a subject’s breath sample. The rule does not require the operator to ascertain the actual temperature of the simulator solution. This makes sense since the DataMaster does not record actual temperature. Rather, when the operator observes a temperature within the prescribed range, he or she may proceed with the test when the machine records “SIM TEMP 34c +/- .2c: YES” on the breath test document. Contrary to defendants’ position, the rule does not require, nor provide a method for, determining the actual temperature or the accuracy of the thermometer. Nor does the actual operation of the machine lend itself to such a regulation.
If we accepted the defendants’ interpretation of former WAC 448-13-040 the breath test results would be inadmissible in every case, unless, as the defendants suggest, an operator additionally records the actual temperature reading and then, using the thermometer variance of +/- 0.1, calculates whether the actual temperature falls within the rule’s range. We do not believe that the toxicologist intended to promulgate a rule containing requirements that are beyond the performance abilities of the machine or that require an operator to take steps that are not included in the rule. Accordingly, we conclude that compliance with former WAC 448-13-040 requires only that the breath test ticket reflect that the temperature was within the specified range. This construction is consistent with the language and purpose of the rule, which is to set forth the steps that must be followed to obtain a valid test, as well as with the actual operation of the machine.
The defendants argue, though, that 2001 amendments to WAC 448-13-040 support a conclusion that the toxicologist must have intended that the simulator solution temperature be exactly 34 degrees centigrade plus or minus 0.2 degrees centigrade to produce a valid test result under the former regulation. In an emergency rule-making order *84amending WAC 448-13-040, the state toxicologist specifically changed the temperature range for the simulator solution to 34 degrees centigrade plus or minus 0.3 degrees to account for the 0.1 degree variance built into the thermometers.1 In issuing the order, the state toxicologist wrote:
Judges in Renton District Court and Bellevue Municipal Court have ruled that the thermometers used in the simulators on breath test instruments do not have sufficient accuracy to meet the existing WAC standard of thirty-four degrees plus or minus 0.2 degrees centigrade, which impacts the admissibility of the breath test result. Other courts may follow suit. All parties have stipulated that the limitations of the thermometers do not affect the accuracy of the results of the breath test.
In light of the ruling from Renton, the acceptable variance specified in the WAC for the temperature of the simulator at the time of the test is being expanded to be plus or minus 0.3 degrees centigrade. This permits the continued use of the current instrument standard of plus or minus 0.2 degrees centigrade at the time of the test, and recognizes the limits of accuracy of the thermometer. An additional provision requires the thermometers to be certified at least annually.
These provisions are intended to address the concerns of the courts on the admissibility of breath alcohol test results, and to permit all future tests to be considered as evidence provided they meet these and the existing requirements of the administrative code.
Proposed Rules to WAC 448-13-040, St. Reg. 01-11-134 (May 23, 2001) (emphasis added).
In response to two comments received regarding the adoption of the new rule, the state toxicologist explained further:
Question: Why was the acceptable range for the thermometer *85reading not changed to 34 degrees plus or minus 0.1 degrees instead of 0.3 degrees?
Response-. This question reflects a misunderstanding of the issue ruled on by judges in Renton and Bellevue district courts in King County. These courts found that there was no explicit recognition in the WAC of the limits of accuracy of the mercury in glass thermometers used in the breath test equipment, and that thus, any variability in the thermometer must be included within the acceptable range. By enlarging the acceptable range to 0.3 degrees centigrade, but continuing to require a thermometer reading of 34 degrees plus or minus 0.2 degrees in the operation of the program, the potential variance in the thermometer is explicitly recognized and allowed for. Changing this allowable range does not introduce any additional inaccuracy into the measurement of the subject’s breath alcohol concentration.[2]
Id. at ex. 5 (Permanent Rule Adoption for WAC 448-13-040, St. Reg. 01-17-009 (Aug. 2, 2001)).
The language of the amendment and the order do not support the defendants’ construction. As the toxicologist’s order states, his decision to amend the rule to account for the variation in thermometers was based on the decisions of two courts that any variation had to be included within the rules. His expressed concern was that other courts might make similar rulings. As his response to questions makes clear, the amendment changing the temperature range to expressly recognize thermometer variances does not change the requirement that the temperature fall within the range of 34 degrees centigrade plus or minus 0.2 degrees centigrade. The amendment does not undercut reliability of the test under the former rule.
Finally, the defendants’ construction is not necessary to ensure accuracy or reliability for the purpose of general admissibility. In Baker the officers waited 14 minutes before administering a breath test. This court held that the *86foundation for admissibility was not met because the WAC requires a 15-minute waiting period and literature from experts in the field established that the 15-minute waiting period is necessary to give an accurate measure of the concentration of alcohol in the blood. Baker, 56 Wn.2d at 856. Similarly, in Ford, 110 Wn.2d at 833, and Straka, 116 Wn.2d at 870-71, this court emphasized that the purpose of requiring compliance with the regulations is to assure accuracy and reliability of the test results for general admissibility. In this case, the 2001 amendment to WAC 448-13-040 and the accompanying emergency order indicate that the toxicologist did not believe minor variations in the machine’s thermometer affect the accuracy or reliability of the test results.
Based on the language of former WAC 448-13-040, we hold that the breath test documents in these cases constitute a sufficient foundation for admissibility of the test results and arguments as to reliability of the particular test results are questions for the jury. Straka, 116 Wn.2d at 875; see State v. Watson, 51 Wn. App. 947, 951, 756 P.2d 177 (1988) (“once the [breath test] evidence is rendered admissible by demonstrating compliance with administrative regulations, the defendant may attack the machine’s reliability by presenting evidence to the jury”) (citing State v. Franco, 96 Wn.2d 816, 639 P.2d 1320 (1982); City of Bremerton v. Osborne, 66 Wn.2d 281, 401 P.2d 973 (1965)).
The trial court’s order suppressing breath test results is reversed and the cases are remanded for further proceedings.
Alexander, C.J., and Smith, Ireland, Bridge, and Owens, JJ., concur.
The amended WAC 448-13-040 now requires:
Prior to the start of the test the operator must verify that the thermometer, certified per WAC 448-13-035, indicates that the temperature of the simulator solution is thirty-four degrees centigrade plus or minus 0.3 degrees centigrade.
The emergency order postdated the tests in this case and neither party argues for its application to these cases.