Which statement correctly defines a positive XRF result in relation to the standard?

Which statement correctly defines a positive XRF result in relation to the standard?

• A. Lead is present on the testing combination at or above the federal standard.
• B. Lead is absent from the tested surfaces.
• C. The result is inconclusive and requires retesting.
• D. The reading cannot be interpreted.

Answer: (A)

The thing being tested is whether the surface contains lead at a level that meets or exceeds the federal threshold. An XRF result is considered positive when the lead present on the tested area is at or above that regulatory standard. In other words, the surface has lead at a concentration that the standard treats as a lead-containing, potentially hazardous condition. A negative result would mean the lead level is below the standard, while inconclusive or unreadable readings require retesting, but those aren’t considered positive findings. So the best interpretation is that lead is present on the testing area at or above the federal standard.

The thing being tested is whether the surface contains lead at a level that meets or exceeds the federal threshold. An XRF result is considered positive when the lead present on the tested area is at or above that regulatory standard. In other words, the surface has lead at a concentration that the standard treats as a lead-containing, potentially hazardous condition. A negative result would mean the lead level is below the standard, while inconclusive or unreadable readings require retesting, but those aren’t considered positive findings. So the best interpretation is that lead is present on the testing area at or above the federal standard.