CDC Blood Lead Reference Value (3.5 µg/dL)
Summary
The CDC Blood Lead Reference Value (BLRV) of 3.5 µg/dL is the screening threshold used to identify US children with elevated blood lead concentrations relative to most US children. The BLRV is set at the 97.5th percentile of blood lead values in US children ages 1 to 5 years from NHANES 2015-2016 and 2017-2018 cycles, meaning children at or above the BLRV represent the top 2.5 percent of measured blood lead. The value is not a health-based threshold (lead has no demonstrated safe blood level for children); it is a population-percentile-based screening tool for public health intervention. The BLRV is the input to FDA’s Closer to Zero Interim Reference Level for dietary lead, derived through dietary-to-blood-lead conversion factors with a 10x safety factor.
Key numbers
| Parameter | Value |
|---|---|
| Current BLRV | 3.5 µg/dL |
| Statistical basis | 97.5th percentile of blood lead in US children ages 1-5 |
| Source survey | NHANES 2015-2016 and 2017-2018 cycles |
| Population represented at-or-above BLRV | Top 2.5 percent of measured US child blood lead |
| Year of update from prior 5 µg/dL value | 2021 |