Experiment to explore the effects of a hand cleaner such as GOJO containing limonene in the ambient air respecting reliability of the alcohol standard. 100 SAS in simulator at 34.0C. Operator runs ACACA mode. Cal. check drops from 103 to 81, 96, 85 when hand cleaner in air near breath tube on prior air blank and then returns to 111, 105. Note that 111 is outside of acceptable range. It appears that ambient hand cleaner in the breath room can reduce an apparent cal. check by 20 mg/100mls. Although the breath test result itself may be reduced, the reliability of the simulator/alcohol standard has been compromised and so the breath test itself is not reliable. If the instrument is, for example, reading 11 mgs/100 mls too high and the problem is not with the simulator (note the 111 cal. check), then this inaccuracy may be masked. Cal. checks could be in the normal 90 to 110 mgs/100mls range only because the cal. check reliability was compromised by the ambient limonene and the instrument's response thereto.