Beta Elimination Rate (Beta)
Definition
The rate at which BAC falls during the post-absorptive phase of alcohol metabolism, expressed as mg/100 mL/hour. Population mean approximately 15 mg/100 mL/h, range 10-25 mg/100 mL/h.
- Symbol
- Beta (b)
- Unit
- mg/100 mL/hour
- Population mean
- Approximately 15 mg/100 mL/h
- Typical range
- 10 to 25 mg/100 mL/h
Common questions
What is beta used for in forensic casework?+
It is the key input for back-calculating BAC at an earlier time, such as the moment of driving, from a measured BAC at a later blood draw.
Why is using a population-average beta risky in an individual case?+
The true rate for one person can fall well outside the 10-25 range depending on chronic drinking history, body composition, and whether absorption is still ongoing, so applying the average alone can produce a materially wrong retrograde estimate.
Related terms
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- DB-ALC1 / DB-ALC2
- A matched pair of Agilent fused-silica GC columns used for dual-column orthogonal confirmation of blood ethanol. DB-ALC1 uses a polyethylene glycol stationary...
- Internal Standard (IS)
- A compound chemically near-identical to the analyte, often a deuterated isotopologue (d3-morphine, d5-EDDP, d5-alprazolam, pyrene-d10), spiked into every sample at a known...
- NIST SRM 1828
- A series of NIST-certified reference material aqueous ethanol standards (0.02 to 0.40 per cent w/v) used to calibrate forensic blood ethanol analytical...
- Partition Coefficient (K)
- The ratio of analyte concentration in the liquid phase to concentration in the gas phase at equilibrium. For ethanol in blood at...
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- Static Headspace
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- Widmark Factor (Rho / R)
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