Which substance is NOT listed as a potential cause of false positives for chemical detectors?

• A. Acetone vapor
• B. Antifreeze
• C. Petroleum base products
• D. Diesel exhaust

Answer: (A)

False positives happen when substances trigger a detector even though the target contaminant isn’t present, usually because they share similar chemical properties or detection pathways with the interferent. Detectors that respond to hydrocarbon-like vapors are particularly susceptible to interference from other hydrocarbon-rich substances. That’s why antifreeze, petroleum base products, and diesel exhaust are commonly listed as potential false positives—they can produce signals similar to what the detector is looking for. Acetone vapor, on the other hand, isn’t listed as a potential false positive in the material you’re using, so it’s not expected to cause a false alarm in that context. In short, the others are known interferents for these detectors, while acetone isn’t flagged as one here.