Refrigeration alone did not prevent ethanol formation in the postmortem tissue homogenates studied by Lewis and colleagues. All nine specimens formed additional ethanol without storage preservative, including at 4°C. Homogenizing matched tissue portions with sodium fluoride solution largely prevented that increase under the tested conditions.
What tissue and conditions were tested?
The 2004 study examined one tissue specimen from each of nine separate aviation fatalities: four muscle specimens and five kidney specimens. Cases were deliberately selected because earlier testing suggested microbial contamination, through unusual ethanol distribution or other volatile compounds. They were not a random sample of all postmortem tissues.
Specimens came from material archived at −20°C, which the laboratory retained for up to five years. After thawing, each tissue was divided and weighed. One portion was homogenized with two parts water; the other was homogenized with two parts of a 1.00% weight/volume sodium fluoride solution. Each preparation was then split between storage at 4°C and 25°C.
The stated 1.00% describes the fluoride solution added during preparation. It should not be silently relabeled as a measured 1.00% final concentration in the complete tissue homogenate. No organisms or extra glucose were deliberately added, although homogenization and repeated sampling distinguish this experiment from an intact body.
What changed during storage?
Initial tissue ethanol concentrations ranged from 1 to 28 mg/hg, averaging 11 mg/hg. Here, mg/hg means milligrams per 100 grams of tissue. These weight-based tissue results should not be relabeled as blood concentrations in mg/dL.
Without preservative, the nine refrigerated specimens increased by 22–75 mg/hg after 96 hours, averaging 42 ± 15 mg/hg. At 25°C, the increases were 19–84 mg/hg after 48 hours, averaging 45 ± 22 mg/hg. The endpoints were different: these averages are not a same-duration temperature comparison.
For example, kidney specimen 8 started at 1 mg/hg and reached 76 mg/hg after 96 hours at 4°C. Its room-temperature counterpart reached 62 mg/hg after 48 hours. Refrigeration slowed formation but did not eliminate it in these selected materials.
The fluoride-prepared portions showed no significant increase as reported by the authors at either temperature. This does not mean every numerical result was unchanged: kidney specimen 7 went from 28 to 33 mg/hg at 4°C, which the authors considered likely experimental or instrumental variation.
How were the concentrations measured?
Ethanol was quantified by headspace gas chromatography with flame-ionization detection, using two analytical columns and a tert-butanol internal standard. Identification used retention times on both columns. The reported analytical detection and quantification limits were 0.10 and 1.00 mg/dL, respectively, for the liquid measurement method; the tissue findings were calculated and reported in mg/hg.
The analytical internal-standard solution also contained fluoride for salting out during measurement. That preparation step should not be confused with adding preservative before the experimental storage period. A specimen can be measured accurately after ethanol has already formed in storage.
What the experiment supports—and what it cannot determine
The study supports documenting tissue preparation, preservative addition and the entire temperature-and-time history. It demonstrates a mechanism for a stored tissue result to exceed its earlier value without additional drinking.
It does not estimate how often this happens across all fatalities, identify the responsible microbial species, or provide an hourly formation rate for an intact body. The tissues were selected for suspected contamination, previously frozen and homogenized. The authors also found no discernible pattern among the other measured volatiles that could resolve the ethanol question in every specimen.
These results cannot partition a particular positive result into consumed and postmortem-formed ethanol, reconstruct a blood alcohol concentration, or establish impairment or cause of death. Preservation findings also depend on the matrix and circumstances; compare the separate serial-testing case involving preserved postmortem blood.
Primary source
Lewis RJ, Johnson RD, Angier MK, Vu NT. Ethanol formation in unadulterated postmortem tissues. Forensic Science International. 2004;146(1):17–24. doi:10.1016/j.forsciint.2004.03.015.
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