Unit Converter
Ethylene Glycol
(Clinical & Forensic Alcohol Level – Toxicology, Overdose, Impairment & Metabolic Disorders)
Synonyms
- Ethanol
- Ethyl alcohol
- Blood alcohol concentration (BAC)
- Serum ethanol
- Alcohol level
- Blood alcohol level (BAL)
Units of Measurement
- mmol/L
- µmol/L
- mg/dL
- mg/100 mL
- mg%
- mg/L
- µg/mL
Key Conversions
1 mg/dL = 0.217 mmol/L
1 mg/dL = 10 mg/L
1 µg/mL = 1 mg/L
mg/dL = mg% = mg/100 mL
Legal BAC units:
- mg/dL
- mg%
- mg/100 mL
- g/L, g/dL (regional)
Description
Ethanol is the primary ingredient of alcoholic beverages.
Clinically, ethanol levels are used for:
- Alcohol intoxication
- Ethanol poisoning
- Trauma evaluation
- Liver disease
- Ketoacidosis workup
- Forensic/legal purposes
Ethanol is absorbed rapidly, mainly via:
- Stomach
- Small intestine
Metabolized mostly in the liver by:
- Alcohol dehydrogenase (ADH)
- MEOS (microsomal ethanol-oxidizing system)
- Catalase (minor route)
Physiological Role
Ethanol has no physiological role - it is purely a xenobiotic (foreign substance).
It affects:
- CNS
- Respiratory centers
- Cardiovascular system
- Metabolic pathways
Clinical Significance
High Ethanol Levels
1. Acute Alcohol Intoxication
Symptoms depend on concentration:
| Ethanol Level (mg/dL) | Clinical Effect |
| 20–50 | Mild euphoria, decreased inhibition |
| 50–100 | Impaired coordination, judgment |
| 100–200 | Marked incoordination, ataxia |
| 200–300 | Confusion, vomiting, drowsiness |
| 300–400 | Stupor, coma |
| >400 | Respiratory depression; potentially fatal |
2. Alcohol Poisoning
- Respiratory failure
- Hypoglycemia
- Lactic acidosis
- Aspiration risk
- Hypothermia
3. Chronic Alcoholism
Ethanol may be elevated due to:
- High tolerance
- Slow clearance
- Altered metabolism
Long-term effects:
- Liver cirrhosis
- Pancreatitis
- Cardiomyopathy
- Neuropathy
4. Metabolic Disorders
Mimics or worsens:
- Diabetic ketoacidosis
- Alcoholic ketoacidosis
- Hypoglycemia
Low / Undetectable Levels
Expected in sober individuals.
Reference Ranges / Legal Limits
(CDC + Forensic Standards + Mayo)
Normal
- 0 mg/dL (no ethanol)
Social drinking
- 10–50 mg/dL (0.01–0.05 g/dL)
Driving legal limits
Varies by country:
- 80 mg/dL (0.08 g/dL): USA, India
- 50 mg/dL (0.05 g/dL): Europe, Australia
- 20 mg/dL (0.02 g/dL): zero-tolerance zones
Toxic
- >300 mg/dL (coma risk)
Potentially fatal
- >400–500 mg/dL
Diagnostic Uses
1. Diagnose Alcohol Intoxication
- Emergency cases
- Altered mental status
- Trauma
- Unexplained metabolic derangements
2. Forensic & Legal Testing
- Drunk-driving cases
- Workplace screening
- Post-mortem toxicology
- Medico-legal injury assessment
3. Alcohol Use Disorder Evaluation
Useful in conjunction with:
- GGT
- CDT (carbohydrate-deficient transferrin)
- AST/ALT ratio
4. Ketoacidosis & Metabolic Disorders
Differentiates:
- Alcoholic ketoacidosis
- DKA with alcohol intoxication
5. Monitoring Withdrawal or Detox
Helps determine timing & severity of withdrawal.
Analytical Notes
- Serum or plasma (fluoride tubes for legal testing to prevent fermentation)
- Enzymatic assay (ADH method) for clinical labs
- Gas chromatography (GC) for forensic accuracy
- Volatile compound → sample must be sealed properly
- Hemolysis minimal effect
- False positives: fermentation in unpreserved samples
Clinical Pearls
- Ethanol is the most commonly tested toxin in emergency settings.
- Levels do not correlate perfectly with clinical symptoms in chronic drinkers (tolerance).
- Hypoglycemia is common in intoxication - check glucose in all cases.
- Co-ingestion with methanol or ethylene glycol requires specific testing.
- Ethanol acts as a competitive substrate for alcohol dehydrogenase and can inhibit metabolism of methanol/ethylene glycol.
Interesting Fact
Ethanol metabolism generates acetaldehyde, responsible for hangover symptoms, vasodilation, flushing, and DNA damage.
References
- Tietz Clinical Chemistry & Molecular Diagnostics, 8th Edition - Toxicology.
- CDC Alcohol & Health Statistics.
- NIH Alcohol Research Center.
- Mayo Clinic Laboratories - Ethanol.
- ARUP Consult - Toxic Alcohol Testing.
- SOFT/AAFS Forensic Toxicology Standards.
- MedlinePlus / NIH - Alcohol Test.