What is the consequence of insufficient contact time during wipe sampling?

• A. It can affect recovery of dust and lead to biased results.
• B. It has no effect if you wipe longer.
• C. It improves results.
• D. It only affects color of dust.

Answer: (A)

Recovery of material during wipe sampling depends on how long the wipe stays in contact with the surface. If that contact time is too short, not all dust and lead particles transfer to the wipe, so the measured amount is too low and the result is biased compared with the true contamination. Standard procedures use a consistent contact time to ensure reliable recovery and avoid underestimating contamination. Extending the wipe duration isn’t a guaranteed fix and other choices miss the central idea: the color of dust isn’t what’s being measured, and there is a real effect of contact time on how much material is recovered.