DESCRIPTION
PHYSICOCHEMICAL PROPERTIES
Colorless, odorless, sweet-tasting, hygroscopic liquid Molecular Weight | 62.07 62.07% degrees C |
Melting Point | -13 -13% degrees C |
Specific Gravity (water = 1) | 1.1274 1.1274% degrees C |
Flash Point | 115 115% degrees C |
Solubility | Water: miscible Ethanol: miscible Glycerol: miscible Acetic acid: miscible Acetone: miscible Ether: slightly soluble Benzene: insoluble Chlorinated hydrocarbons: insoluble Petroleum ether: insoluble Oils: insoluble |
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USES
Ethylene glycol is predominantly used as a deicer or antifreeze in cooling systems. It is also used in hydraulic brake fluids, as a solvent, a chemical intermediate, and as an industrial humectant. It may also be used as a glycerin substitute in commercial products including paints, detergents, and cosmetics. |
INTERVENTION CRITERIA
Medical assessment and observation in an emergency department is recommended for: - Ingestions greater than a witnessed lick or exploratory taste of ethylene glycol - Symptomatic ingestions - Symptomatic eye exposures (other than mild resolving symptoms following flushing) - Significantly symptomatic patients (more than mild irritation) following skin or inhalation exposure |
Medical assessment and observation in an emergency department is recommended for: - Ingestions greater than 10 mL of ethylene glycol - Symptomatic ingestions - Symptomatic eye exposures (other than mild resolving symptoms following flushing) - Significantly symptomatic patients (more than mild irritation) following skin or inhalation exposure - Exposures with intent to self-harm |
If the patient does not require medical observation they can be observed at home for 8 hours in the care of a reliable observer. |
The patient should be medically assessed if any symptoms develop, including: Nausea Vomiting Drowsiness Slurred speech Stumbling or difficulty in moving Confusion Decreased urine output |
If medical observation is required, patients with an undetectable serum ethanol should be monitored until 8 hours post-exposure for the onset of symptoms or biochemical evidence of evolving toxicity. Patients co-ingesting ethanol should be monitored until 12 hours post-exposure. If the patient is asymptomatic at the end of the observation period, with normal serum pH, bicarbonate, and creatinine concentrations and their serum (or breath) ethanol concentration is undetectable they may be: Discharged into the care of a reliable observer, or Referred for psychological assessment if the overdose or exposure was with intent to self-harm |
Patients, particularly children, presenting within an hour of suspected ethylene glycol ingestion or those who have concurrently co-ingested ethanol may not have any abnormal surrogate markers of poisoning. In these instances, close observation and serial monitoring of acid-base profile and renal function status should be performed. Any development of early metabolic acidosis would be highly suggestive of recent ethylene glycol exposure. Serum ethanol concentration (required for osmolar gap calculation) Serum electrolytes including: Sodium (required for anion gap calculation) Chloride (required for anion gap calculation) Bicarbonate (required for anion gap calculation) Calcium Potassium Anion gap (elevated in later stages of poisoning) Blood gas analysis including: Serum pH Creatinine and BUN Urine output Urinalysis including: Proteinuria Hematuria Examination under UV light (Wood’s lamp) for fluorescence Present in many antifreeze solutions and with urinary elimination the urine will fluoresce when exposed to UV light. A negative result does not completely rule out ethylene glycol exposure. Microscopic examination for crystalluria (calcium oxalate crystals) If a serum ethylene glycol concentration measurement is not available a presumptive diagnosis of poisoning may be based on:  either A history of recent ethylene glycol ingestion and osmolar gap > 25 mOsm/L or A history or suspicion of ethylene glycol ingestion plus any 2 of the following: Arterial pH < 7.3 Serum bicarbonate < 20 mmol/L (20 mEq/L) Osmolar gap > 25 mOsm/L Presence of urinary oxalate crystals A serum ethylene glycol is the preferred investigation, but is often not readily available. A significant ethylene glycol ingestion may be inferred from an increased osmolar gap (in the early stages of intoxication) indicating a solute (glycol) load. However, a normal osmolar gap cannot rule out ethylene glycol exposure. Once the glycol is metabolized the osmolar gap will drop and may be replaced by an increased anion gap, indicating an increased organic acids (glycol metabolites) load, with an accompanying metabolic acidosis. Presence in the urine of either fluorescein or calcium oxalate crystals indicates ethylene glycol exposure, but their absence does not exclude this poisoning. Calcium oxalate crystals may not be present until the later stages of intoxications. Fluorescein is rapidly eliminated by the kidneys and may have already been excreted prior to presentation. Also, the ingested ethylene glycol may not contain fluorescein. Care must be exercised when checking for fluorescence as plastic containers may exhibit some degree of fluorescence under a UV light. A glass container is preferable and previous experience with visualizing fluorescein containing urine is useful. |
Admission to an intensive care environment is recommended: Ethylene glycol concentration is > 62 mg/dL (10 mmol/L) Those receiving antidotal therapy Following symptoms occur Coma Seizures Kidney injury Hypotension Ensure the receiving hospital is able to provide: Advanced care/ICU facilities, and |
TREATMENT
TREATMENT SUMMARY
Initial management includes airway protection and adequate minute ventilation, administration of IV fluids, treating seizures with benzodiazepines or barbiturates, and correcting hypoglycemia (unless rapid glucose screen indicates otherwise); concurrently administer thiamine and pyridoxine to support metabolism of ethylene glycol to less toxic products. Nasogastric aspiration may be performed within 1 hour of ingestion provided the airway is protected. Ethanol and fomepizole are effective antidotes and should be administered to patients as early as possible. Hemodialysis is effective in excreting glycols and their toxic metabolites and should be considered in acute renal failure, severe metabolic acidosis, or if other indications are present. Doses of ethanol and fomepizole need to be increased during hemodialysis.   Eye exposures require a 15 minute irrigation with saline or water and if more than mild, resolving symptoms are present following irrigation, an ophthalmologic examination should be undertaken, including slit lamp examination and fluorescein staining. If there is evidence of injury an ophthalmologist should be consulted. Treatment should follow standard protocols for the management of eye irritation. |
EMERGENCY STABILIZATION
Ensure Adequate Cardiopulmonary Function |
Ensure the airway is protected (intubation may be required), and administer oxygen. Establish secure intra-venous access. |
Hypotension may be present due to gastrointestinal fluid loss and alcohol-induced vasodilation, and in such cases fluid replacement with a crystalloid should be performed, having regard to adequate urine output. |
CHILD Hypotension in children is determined by age and systolic blood pressure Age | Hypotension if Systolic Blood Pressure (mm Hg) is: | 0 to 28 days | < 60 | 1 to 12 months | < 70 | 1 to 10 years | < 70 + (age in years x 2) | > 10 years | < 90 |
Administer an isotonic crystalloid fluid 10 mL/kg IV over 5 to 10 minutes If the systolic blood pressure does not return to the normal range, give a further 10 mL/kg body weight of the isotonic crystalloid over 5 to 10 minutes. The intraosseous route can be used if IV access is difficult or delayed. ADULT Administer a bolus of isotonic crystalloid fluid if systolic blood pressure is less than 100 mmHg. Isotonic crystalloid fluid dose: 20 mL/kg IV over 5 to 10 minutes If the systolic blood pressure does not return to the normal range, give a further 10 mL/kg body weight normal saline over 5 to 10 minutes. The intraosseous route can be used if IV access is difficult or delayed. |
Administer a benzodiazepine as first-line treatment to patients with seizure activity.  Blood glucose concentration should be promptly determined. If the result indicates hypoglycemia, or is unobtainable, supplemental dextrose should be administered IV. |
Check for hypoxia and electrolyte disturbances. Correct acid base and metabolic disturbances. Seizures due to ethylene glycol intoxication may prove unresponsive to standard management unless hypocalcemia is corrected. |
IV dextrose is indicated (even if blood glucose cannot be quickly measured) in patients with altered mental status, unusual behavior, coma, or seizures. Hypoglycemic patients may present with focal neurological deficits.  However, these may also be due to cerebral ischemia. |
Must be administered to adult patients considered alcohol-dependent or malnourished.   |
Thiamine dose ADULT 100 mg IV, which may be repeated every 8 hours, if needed. |
Blood pressure ECG Respiratory rate Oxygen saturation Serum ethylene glycol concentration (if available) Serum ethanol concentration (used in calculation of osmolar gap) Osmolar gap (elevated early in poisoning) Electrolytes including: Sodium (required for anion gap calculation) Chloride (required for anion gap calculation) Bicarbonate (required for anion gap calculation) Calcium Potassium Anion gap (elevated later in poisoning) Blood gas analysis including: Serum pH Creatinine and BUN Urine output Urinalysis including: Proteinuria Hematuria Microscopic examination for crystalluria Blood glucose Liver function |
DECONTAMINATION
Nasogastric aspiration is recommended if the quantity of liquid ingested is both systemically toxic and in sufficient volume to aspirate. As this procedure may increase the risk of vomiting and pulmonary aspiration, the airway must be protected in all patients. Accurate placement of the nasogastric tube must also be ensured in all patients. |
Nasogastric aspiration is recommended if the patient has presented early (within 1 hour) following ingestion of ethylene glycol. |
Single Dose Activated Charcoal |
Activated charcoal is not considered an effective decontaminant for this ingestion as ethylene glycol is rapidly absorbed from the gastrointestinal tract and has poor binding affinity for activated charcoal. Unless there is concern for coingestants, there is little benefit from activated charcoal administration in ethylene glycol ingestions.
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Remove contact lenses. Irrigate immediately with water or saline for at least 15 minutes. If the eye is contaminated with solid particles, the eyelid should be completely everted and any solid material removed as quickly as possible while continuing to irrigate the eye. A topical anesthetic should be considered for all patients to enable the patient to open the lids sufficiently for effective irrigation. |
If, following irrigation, any of the following are apparent: Ocular pain (other than mild and resolving) Redness (other than mild and resolving) Decreased visual acuity Ocular discharge/crusting The patient should receive a full ophthalmologic examination, including slit lamp examination and fluorescein staining. If there is evidence of injury, an ophthalmologist should be consulted. |
Remove the patient from the exposure. If respiratory symptoms such as shortness of breath are present, administer oxygen and provide additional support if necessary. |
Remove any contaminated clothing or jewelry. Wash the affected area thoroughly with soap and water until all of the contaminant is removed. |
ANTIDOTE(S)
Appropriate use of antidotes in glycol poisoning is essential. Ethanol has long been regarded as an effective intervention, is cheap and available but requires longer periods of monitoring due to the risk of ethanol intoxication. Fomepizole has proven efficacy,  but suffers the disadvantage of expense and may not be immediately available. Both effectively act (via different mechanisms) by inhibiting the role of alcohol dehydrogenase in ethylene glycol metabolism, thus reducing the metabolic conversion of glycol to toxic metabolites (including glycolic, glyoxylic, and oxalic acid). Thiamine and pyridoxine may be indicated as therapeutic adjuncts. Theoretically, they act as cofactors in the formation of non-toxic metabolites of ethylene glycol. No data exists to support this assumption, but they may benefit those with a history of ethanol abuse or inadequate nutrition (e.g. vitamin deficient patients).  |
Ethanol competitively inhibits alcohol dehydrogenase (ADH) therefore blocking the metabolism to toxic metabolites.
Ethanol has a very high affinity for ADH in comparison to other substrates (for example, 100 times the affinity of ethylene glycol and 20 to 30 times the affinity of methanol).
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Ethanol is indicated if:  - Plasma ethylene glycol concentration greater than 62 mg/dL (10 mmol/L), or - History of recent ingestion of a toxic quantity of ethylene glycol with osmolar gap > 25 mosm/kg, or - History or clinical suspicion of ethylene glycol poisoning and at least two of the following: Arterial pH < 7.3 Serum bicarbonate < 20 mmol/L (20 mEq/L) Osmolar gap > 25 mosm/kg Presence of urinary oxalate crystals Calculation of the osmolar gap should factor in the serum ethanol concentration. |
To balance acceptable therapeutic efficacy with acceptable adverse effects from ethanol intoxication, the blood ethanol concentration should be maintained between 22 and 33 mmol/L (100 to 150 mg/dL).  To achieve this both a loading dose and maintenance dosing are required. Concentrated ethanol diluted for intravenous use may be infused (typically as either 5% or 10% ethanol solution), or liquor (e.g. vodka, gin) may be administered orally. Prior to use of ethanol therapy a blood ethanol determination should be made to identify if the patient has an existing ethanol concentration requiring a modification of the loading dose. Monitoring in an intensive care setting is required during administration. Because of the large inter-individual variability in ethanol metabolism, serum ethanol concentrations should be monitored every 1 to 2 hours, if this is available, to ensure therapeutic ethanol concentrations are maintained. Practical experience suggests that it can be challenging to maintain serum ethanol concentrations within the desired range, emphasizing the importance of regular monitoring and titration of maintenance doses.   As ethanol may cause agitation or depress mental status and respiration, close monitoring of airway and breathing is also required.  |
Use of a nasogastric tube can facilitate administration of oral ethanol and is recommended. Ethanol concentrations of 20% or less may increase tolerability and decrease stomach irritation (e.g. dilute more concentrated spirits with water or fruit juice). The following table can be used as a guide for oral ethanol administration; titration of maintenance doses should be guided by regularly measuring serum ethanol concentrations. Oral | 5% ethanol | 10% ethanol | 20% ethanol | 40% ethanol | Loading dose | 15 mL/kg | 7.5 mL/kg | 4 mL/kg | 2 mL/kg | Maintenance dose/h (not regular drinker) | 2 mL/kg/h | 1 mL/kg/h | 0.5 mL/kg/h | 0.25 mL/kg/h | Maintenance dose/h (regular drinker) | 4 mL/kg/h | 2 mL/kg/h | 1 mL/kg/h | 0.5 mL/kg/h | Maintenance dose/h during HD (not regular drinker) | 4 mL/kg/h | 2 mL/kg/h | 1 mL/kg/h | 0.5 mL/kg/h | Maintenance dose/h during HD (regular drinker) | 8 mL/kg/h | 4 mL/kg/h | 2 mL/kg/h | 1 mL/kg/h |
It is not imperative that the concentration of spirits used exactly match those in the above table. The clinical goal is to achieve and maintain a therapeutic serum ethanol concentration above 22 mmol/L (100 mg/dL) as the desired outcome, while simultaneously avoiding excessively high serum ethanol concentrations as these will have adverse effects of increasing inebriation and can progress to stupor and coma. Note: The term "proof" describing alcohol content of beverages should be halved to obtain the proper % v/v value (e.g. 60 proof = 30% v/v ethanol). Concentrated ethanol solutions need to be diluted with isotonic 5% glucose (dextrose) to prevent vascular damage from hyperosmolarity; administration via central line is essential for 10% ethanol solutions and recommended for 5% solutions. To convert concentrated ethanol formulations to 5 or 10% click here. The following table can be used as a guide for intravenous ethanol administration; titration of infusion rates should be guided by regularly measuring serum ethanol concentrations.  Intravenous | 5% ethanol | 10% ethanol | Loading dose | 15 mL/kg | 7.5 mL/kg | Infusion rate/h (not regular drinker) | 2 to 4 mL/kg/h | 1 to 2 mL/kg/h | Infusion rate/h (regular drinker) | 4 to 8 mL/kg/h | 2 to 4 mL/kg/h | Infusion rate/h during HD (not regular drinker) | 4 to 8 mL/kg/h | 2 to 4 mL/kg/h | Infusion rate/h during HD (regular drinker) | 6 to 10 mL/kg/h | 3 to 5 mL/kg/h |
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The doses suggested above are only a starting point. Maintenance doses should be titrated aiming to achieve the desired blood ethanol concentration of 22 to 33 mmol/L (100 to 150 mg/dL). This is best guided by frequently repeated measurements of serum ethanol concentrations, ideally every 1 to 2 hours initially until a stable concentration within the target range is reached. After this, measurements of serum ethanol can be performed every 2 to 4 hours, with repeated measurements 1 hour after any change of dosing rate. Serum glucose should also be monitored. |
Ethanol administration may be discontinued if ethylene glycol concentrations can no longer be detected or are less than 20 mg/dL (3.2 mmol/L) with a normalized arterial pH and resolved signs of systemic toxicity - this is likely to take 2 to 3 days given ethylene glycol's typical elimination half-life of around 17 to 18 hours in the presence of ethanol, if hemodialysis is not applied.  In settings where serum ethylene glycol concentrations cannot be measured, resolution of the osmolar gap may be used as an imperfect surrogate for elimination. |
Hypoglycemia may occur, especially in children. Once an infusion has been commenced blood glucose concentrations must be determined on a frequent basis (every 1 to 2 hours). It may be necessary to add dextrose to intravenous solutions, or give glucose if ethanol is being administered orally. It is recommended that patients receiving ethanol therapy be monitored in an intensive care setting as ethanol may cause agitation or depress mental status and respiration; close monitoring of airway and breathing is required. |
While availability is limited by purchase price, fomepizole appears preferable to ethanol, especially in those with altered mental status, patients suffering hepatic disease, pregnant women, those critically ill but lacking confirmation of poisoning, or lack of local availability to measure repeated ethanol concentrations or a facility to monitor the patient closely such as an intensive care unit. Its administration to pediatric patients avoids the disadvantages of ethanol (e.g. inebriation, hypoglycemia). |
Fomepizole is indicated if: - Plasma ethylene glycol concentration greater than 62 mg/dL (10 mmol/L), or - History of recent ingestion of a toxic quantity of ethylene glycol with osmolar gap > 25 mosm/kg, or - History or clinical suspicion of ethylene glycol poisoning and at least two of the following Arterial pH < 7.3 Serum bicarbonate < 20 mmol/L (20 mEq/L) Osmolar gap > 25 mosm/L Presence of urinary oxalate crystals |
Loading dose  - 15 mg/kg diluted in 100 mL of normal saline or 5% dextrose in water and administered by IV infusion over 30 minutes Maintenance doses  - 10 mg/kg should be administered every 12 hours for 4 doses, then; - 15 mg/kg every 12 hours thereafter if indicated Maintenance fomepizole should be administered in the same fashion as the loading dose. Dosing requirements will change if hemodialysis is required – as outlined in the enhanced elimination section. |
Fomepizole may be discontinued when ethylene glycol plasma concentrations are either undetectable, or below 20 mg/dL (3.2 mmol/L) in patients with a normal pH and resolved signs of systemic toxicity.  |
Abdominal pain, skin rash, nausea, headache, dizziness, and drowsiness have been reported following fomepizole use.  |
Pyridoxine acts as a co-factor in the conversion of glyoxylic acid to the non-toxic metabolite glycine. While the clinical benefit of pyridoxine administration for the treatment of ethylene glycol poisoning has not been demonstrated in healthy individuals, it is recommended for use in malnourished or alcohol dependent patients who may have vitamin deficiencies.  |
The formulation should be diluted at least 1 to 5. ADULT - 50 to 100 mg pyridoxine given as an IV infusion over 15 to 30 minutes every six hours - Continue for two days  |
Profound peripheral neuropathy may occur after very large single doses  or a series of doses (for example a total of > 2 g/kg pyridoxine over a three day period).  The sensory (if not motor) disturbances are potentially irreversible.  |
Thiamine acts as a co-factor in the conversion of glyoxylic acid to the non-toxic metabolite alpha-hydroxy-beta-ketoadipate. While the clinical benefit of thiamine administration for the treatment of ethylene glycol poisoning has not been demonstrated in healthy individuals, it is recommended for use in malnourished or alcohol dependent patients who may have vitamin deficiencies.  |
ADULT - Administer 100 mg IV or IM thiamine every six hours - Continue for two days  |
ENHANCED ELIMINATION
Hemodialysis is a highly effective method to enhance excretion of glycols and their toxic metabolites, reducing duration of antidote use and enhancing patient outcome. The approximately 6-hour elimination half-life of ethylene glycol may be reduced to 2.5 to 3.5 hours with intermittent hemodialysis.    In severe poisonings it can be life-saving. If renal replacement therapy is prolonged, monitor for and treat hypophosphatemia. Hemodialysis is indicated where:  Clinical signs are deteriorating despite intensive supportive care, or Metabolic acidosis with pH < 7.25 unresponsive to therapy, or Acute kidney injury, or Serum ethylene glycol concentration > 50 mg/dL (8.1 mmol/L) in those not receiving antidotal therapy Intermittent hemodialysis is preferred but hemoperfusion or other continuous renal replacement therapies are acceptable alternatives if hemodialysis is not available. ADH inhibitors are to be continued during renal replacement therapy. Renal replacement therapy should continue until clinical improvement (acid-base and renal function have normalized and signs of systemic toxicity have resolved) and serum ethylene glycol concentrations is 20 mg/dL (3.2 mmol/L) or less. In the absence of serum ethylene glycol concentration measurement, renal replacement therapy can be stopped when osmolar gap, anion gap, electrolyte concentrations, acid-base, and renal function have normalized. Ethanol should continue during renal replacement therapy. As ethanol is dialyzed, infusions must be increased (approximately doubled during intermittent hemodialysis) or 95% ethanol added to the dialysate. Further infusion rates must be guided by regular measurement of serum ethanol concentration. Immediately post renal replacement therapy ethanol may need to be continued until confirmation is obtained that toxic alcohol concentrations are below treatment thresholds. The dose of fomepizole must be increased during renal replacement therapy (for both intermittent hemodialysis and continuous renal replacement therapy modalities) to compensate for fomepizole elimination from the procedure. Intermittent Hemodialysis If hemodialysis is started six or more hours after the last administration of fomepizole, the next scheduled dose should be given at the commencement of the procedure. All patients should then receive additional fomepizole doses every four hours for the duration of the hemodialysis run.  Immediately post-hemodialysis fomepizole may need to be continued until confirmation is obtained that toxic alcohol concentrations are below treatment thresholds. In this scenario, post-dialysis dosing should be given as follows:  - If time since last dose administered is within one hour a further dose is not required. Resume 12 hourly dosing thereafter until treatment cessation criteria met - If time since last dose is within 1 to 3 hours, then the patient should be administered half their next scheduled dose at the completion of dialysis. Resume 12 hourly dosing thereafter until treatment cessation criteria are met - If time since last dose is more than 3 hours ago, then the patient should receive their full dose at the completion of dialysis. Resume 12 hourly dosing thereafter until treatment cessation criteria are met Continuous Renal Replacement Therapy Continuous renal replacement therapy modalities will remove less fomepizole at a slower rate as compared to hemodialysis, therefore those on continuous renal replacement therapy should be administered additional fomepizole doses every eight hours for the duration of treatment. Post-hemodialysis monitoring Patients may suffer acute kidney injury as a result of their poisoning and require hemodialysis for some weeks. It is usual (but not inevitable) that full renal function will return. |
SUPPORTIVE CARE
Level of consciousness Blood pressure ECG Respiratory rate Oxygen saturation Serum ethylene glycol concentration (if available) Serum ethanol concentration (used in calculation of osmolar gap) Osmolar gap (elevated early in poisoning) Electrolytes including: Sodium (required for anion gap calculation)
Chloride (required for anion gap calculation) Bicarbonate (required for anion gap calculation) Calcium Potassium Anion gap (will be increased in later stages of poisoning) Blood gas analysis including: Serum pH Creatinine and BUN Urine output Urinalysis including: Proteinuria Hematuria Microscopic examination for crystalluria Blood glucose Liver function Head CT (if neurological abnormality) |
Increased anion gap metabolic acidosis results from the metabolism of ethylene glycol to acidic metabolites, predominantly glycolic acid. In severe acidosis, use of hemodialysis in addition to an antidote to halt production of acidic metabolites is necessary. Intravenous sodium bicarbonate may be considered as an adjunctive treatment in cases of severe metabolic acidosis. |
Monitor: Blood gases Plasma lactate |
Manage metabolic acidosis following standard treatment protocols. |
Early use of hemodialysis must be considered for any patient with metabolic acidosis. |
Patients should be monitored for the onset of acute kidney injury: Urine output Serum creatinine Blood urea nitrogen (urea) Proteinuria |
Manage acute kidney injury following standard treatment protocols. |
Calcium is recommended for patients continuing to seize despite standard anticonvulsant management, or in the presence of cardiac dysrhythmia – particularly prolonged corrected QT interval (greater than 500 ms). Available ionized calcium will rise with increasing acidosis (due to release from plasma proteins) and fall with return to normal serum pH. Prophylactic calcium or treatment of asymptomatic hypocalcemia is not recommended due to the risk of further precipitation of calcium oxalate in the tissues.  |
Monitor for onset of hypocalcemia with: Observation for signs and symptoms of hypocalcemia Serum ionized calcium Serum electrolytes (hypomagnesemia and hyperkalemia are often also present) |
Magnesium is a cofactor with thiamine in the metabolic detoxification of ethylene glycol metabolites. Serum magnesium concentrations should be monitored and hypomagnesemia corrected.  |
Monitor: Serum magnesium Nausea and vomiting Lethargy, weakness, fatigue Tremor Hyperreflexia |
Manage hypomagnesemia following standard treatment protocols. |
Hyperkalemia can occur in association with metabolic acidosis due to the formation of acidic metabolites. To prevent worsening acidosis, an antidote (ethanol or fomepizole) and bicarbonate should be administered and hemodialysis performed to correct potassium concentrations. |
Monitor: Serum potassium Blood gas analysis Renal function and urine output ECG for changes suggestive of hyperkalemia including Peaked T waves (tenting) Flattened P waves Prolonged PR interval (first-degree heart block) Widened QRS complex Deepened S waves and merging S and T waves Idioventricular rhythm Sine-wave formation VF and cardiac arrest |
Drowsiness, ataxia, slurred speech, and stupor are common early signs of ethylene glycol intoxication. Ethylene glycol metabolites, namely glycoaldehyde, glycolic acid, and glyoxylic acid, may contribute to CNS depression. |
Closely monitor level of consciousness. |
Manage depressed level of consciousness following standard treatment protocols. |
Seizure activity unresponsive to standard management is typically indicative of hypocalcemia, particularly in the presence of calcium oxalate crystalluria, or following administration of sodium bicarbonate (which can lower ionized serum calcium). Calcium is recommended for patients continuing to seize despite standard anticonvulsant management.  Seizure-related hypoxic encephalopathy may also occur.  |
Observe the patient closely for onset of seizure activity. |
Closely monitor patients for onset of neurotoxicity. |
Manage neurotoxicity following standard treatment protocols. |
Profound hypotension has been reported due to critical circulatory failure. The exact mechanism is unknown. |
Monitor: Heart rate/rhythm Blood pressure ECG Level of consciousness End-organ perfusion |
Manage hypotension following standard treatment protocols. |
Acute liver dysfunction may develop with significant toxicity. Elevated ALT and bilirubinemia has been reported.  |
Hepatic monitoring should include: Alanine aminotransferase (ALT) Aspartate aminotransferase (AST) International normalized ratio (INR) Serum bilirubin Blood or plasma glucose Serum lactate |
Manage acute hepatotoxicity following standard treatment protocols. |
Acute Respiratory Distress Syndrome |
Acute respiratory distress syndrome has been reported in the presence of normal cardiac function. It is speculated that it may be due to direct toxic effect from ethylene glycol metabolites. Respiratory support with mechanical ventilation and positive end-expiratory pressure may be required. |
Monitoring for acute respiratory distress syndrome should include: Oxygen saturation Blood gas analysis Chest X-ray Heart rate Blood pressure ECG Urine output Fluid balance Serum electrolytes Level of consciousness |
Pulmonary edema may occur in severe ethylene glycol poisoning. Death can occur within 24 to 72 hours. |
Pulmonary edema usually manifests with desaturation, tachypnea, and pulmonary crepitations. Occasionally frothy, pink sputum may be apparent. Monitoring for this condition should include: Chest auscultation Oxygen saturation Blood gas analysis Chest x ray |
Manage pulmonary edema following standard treatment protocols. |
DISCHARGE CRITERIA
All asymptomatic patients should be observed until appropriate investigations have been carried out, serum pH is normal, venous bicarbonate concentration is greater or equal to 20 mmol/L (mEq/L), and serum (or breath) ethanol concentration is undetectable. If treatment is not required they may be: - Discharged into the care of a reliable observer, or - Referred for psychological assessment (if the overdose was intentional) Symptomatic patients may be considered for discharge once ethylene glycol concentrations are undetectable (if available) and/or all of the following criteria are met: serum pH is normal, venous bicarbonate concentration is greater or equal to 20 mmol/L (mEq/L), serum (or breath) ethanol concentration is undetectable, and toxic sequelae have resolved. In some cases, patients may exhibit transient renal impairment, requiring continuing dialysis. Furthermore, ongoing cranial nerve palsies may occur, but typically resolve within weeks to months. Rehabilitation may be required during this time. |
FOLLOW UP
Standard protocols should be used for follow-up of patients suffering renal failure or CNS effects. Psychiatric intervention may be necessary depending on the circumstances of the exposure.
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PROGNOSIS
Those patients surviving an initial severe acidosis may face oliguric renal failure and require regular hemodialysis for weeks to months.   Fortunately, recovery is expected and very few cases lead to permanent renal failure. The return of renal function is usually signified by an increase in urine output and concomitant decrease in serum creatinine. Those who develop severe CNS manifestations, including seizures and coma, can recover full neurologic function. Cranial nerve palsies may occur in nerves II, V, VII, VIII, IX, and XII, typically resolving over weeks to months  though ongoing mild defects may persist.  |
SIGNS AND SYMPTOMS
Inhalation of ethylene glycol can cause upper respiratory tract irritation. Systemic effects are not expected unless it has been heated or aerosolized.  Eye exposure to vapors or direct contact with the liquid may lead to eye irritation;  significant eye injury would not be expected. Brief or occasional skin exposure is unlikely to cause harm to the skin but prolonged or repeated exposure may lead to significant irritation and sensitivity.  Skin absorption is limited, and systemic effects are unlikely to develop.  |
Symptoms predominantly occur following ingestion of ethylene glycol. However, toxicity is also possible via intravenous and intramuscular routes. |
Onset/Duration of Symptoms |
Stage I: Neurological Phase 0.5 to 12 hours post-ingestion Inebriation Nausea Vomiting/hematemesis Metabolic acidosis/elevated anion gap/elevated osmolar gap CNS depression Coma Hypocalcemia Calcium oxalate crystalluria Stage II: Cardiopulmonary Phase 12 to 24 hours post-ingestion Hypertension Tachycardia Tachypnea Severe metabolic acidosis Pulmonary edema Congestive heart failure Stage III: Renal Phase 24 to 72 hours post-ingestion Proteinuria Oliguria Anuria Acute tubular necrosis Renal failure Sequelae Onset several (5 to 20) days after ingestion Cranial nerve neuropathies |
Mild Ethylene Glycol Toxicity | Moderate Ethylene Glycol Toxicity | Severe Ethylene Glycol Toxicity | Nausea Vomiting Ataxia Slurred speech Confusion Drowsiness | Mild metabolic acidosis Tachycardia Hypertension Hypocalcemia Calcium oxalate crystalluria Oliguria Hematuria Proteinuria | Pulmonary edema Anuria Hyperventilation/Kussmaul respirations Hyperkalemia Elevated anion and osmolar gaps Severe metabolic acidosis Seizures Acute kidney injury Multiple organ failure Cranial nerve defects Coma Death |
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ACUTE EFFECTS (ROUTE OF EXPOSURE)
Exposures via inhalation are rare due to the low vapor pressure of ethylene glycol at normal temperatures. However, when heated or aerosolized, exposures may occur. Upper respiratory tract irritation and cough have been reported. Chronic inhalation has caused nystagmus, periods of unconsciousness, and lymphocytosis. |
Ethylene glycol is slightly irritating to the skin.   Repeated skin exposures may result in sensitivity including erythema and edema.  Dermal absorption is limited; acute contact is unlikely to produce systemic effects.  |
There are limited human reports involving eye exposures to ethylene glycol. However, in animal studies, direct eye contact may result in immediate eye irritation with temporary conjunctival inflammation and swelling. Significant corneal damage would not be expected.  |
ACUTE EFFECTS (ORGAN SYSTEM)
Hypothermia   Hypoglycemia   NB. A normal anion or osmolar gap does not rule out ethylene glycol ingestion.   NB: With certain ethylene glycol assays, some metabolites can produce falsely elevated serum lactate levels.  |
Proteinuria   Albuminuria  Dysuria  Azotemia  Incontinence  Urinary tract infection  |
Wheeze   Bradypnea   Hypoxia  Pneumonia   Adult respiratory distress syndrome  |
Bradycardia   QRS widening  Cardiogenic pulmonary edema  Cardiorespiratory arrest  |
Hyponatremia  Hypernatremia  Hypobicarbonemia  |
Hematemesis  Sialorrhea  |
Decreased visual acuity   Miosis  |
Myalgia (muscle pain)   Increased creatine kinase (CK)   Rhabdomyolysis  |
Elevated ALT  Bilirubinemia  |
Anemia   Thrombocytopenia  Methemoglobinemia  Bone marrow arrest  Disseminated intravascular coagulation  |
CHRONIC EFFECTS
Chronic exposures to ethylene glycol vapor may result in nystagmus, unconsciousness, and lymphocytosis.  |
TOXICITY
HUMAN
Ethylene glycol serum concentrations are not a predictor of toxicity due to metabolism to more toxic metabolites. Patients with low arterial blood pH, severe metabolic acidosis, hyperkalemia, seizures, and/or coma are at a high risk of death.  Co-ingestion of ethanol may delay toxic effects.  Medical assessment is warranted for any ingestion of pure ethylene glycol greater than a witnessed lick or taste in a child or more than a 'swallow' (10 to 30 mL) in an adult. For ingestions of lower concentration products (<20%), any ingestion greater than 0.1 mL/kg of pure substance equivalent warrants referral.  |
29.5 mL Antifreeze (ingested) 17 year male: dizziness, incoordination, confusion, dysuria, nausea, abdominal pain, emesis, tenderness in upper right quadrant, and calcium oxalate crystals in urine. Impaired renal function with elevated BUN developed on day 3. On day 7 developed azotemia, acidosis, and anemia Supportive care Recovered and discharged after 7 days 59 mL Ethylene glycol (ingested) 17 year male: disorientation, unable to ambulate, urinary incontinence, and calcium oxalate crystals in urine. On day 3 developed elevated BUN Supportive care Recovered and discharge after 9 days 100 mL ethylene glycol (ingested) 2 year male: initially vomited and found unconscious the following morning. On arrival was semi-conscious, hyperventilation, tachycardia, and hypotension. Hematemesis, oliguria, hematuria, albuminuria, decreased serum bicarbonate, metabolic acidosis, and elevated BUN occurred. Later developed seizures and had athetoid movements Supportive care, including IV calcium gluconate, ethanol infusion, frusemide, peritoneal dialysis, diazepam, and phenobarbitone Recovered after 17 days 100 mL antifreeze solution (ingested) 13 year old female: within 30 minutes developed tachycardia, hypertension, and elevated pO2. Ataxia and dysarthria also developed. Urinalysis revealed calcium oxalate crystals. Serum ethylene glycol concentration was 103 mg/dL Supportive care, including IV ethanol, orotracheal intubation, and IV fomepizole Recovered and discharged after 3 days 88 to 118 mL Ethylene glycol (ingested) 17 year female: Within 36 hours presented with confusion, seizures, semi-comatose state, vomiting, metabolic acidosis, and hyperkalemia. Later developed cyanosis, hypotension, mild tachycardia, tachypnea with Kussmaul respirations, myoclonic jerks, mydriasis and pupils unreactive to light, papilledema, hypoactive deep tendon reflexes, and pulmonary edema Supportive care, including oxygen, IV dextrose, hemodialysis, ascorbic acid, and methylene blue Fatal after 47 hours 118 mL Ethylene glycol (ingested) 17 year male: Within 48 hours developed fatigue, headache, blurred vision, nausea, confusion, ocular palsy, anuria, bilateral ophthalmoplegia, and hypertension. Later developed bronchopneumonia, renal failure, and calcium oxalate crystals deposits Supportive care, including lumbar puncture, potassium, sorbitol, and hemodialysis Fatal after 17 days Unknown amount of antifreeze (ingested) 6 year female: presented with metabolic acidosis, responsive to pain only, tachycardia, tachypnea, hypertension, emesis, and crystalluria. Elevated anion gap, lactate, sodium, chloride, and glucose were present. Nystagmus developed following fomepizole administration. Polyuria developed at 18 hours. Serum ethylene glycol concentration was 13 mg/dL 3 hours post-admission. Supportive care, including oxygen, IV saline, sodium bicarbonate, IV cefotaxime, pyridoxine, thiamine, fomepizole, hemodialysis, and electrolyte supplementation Recovered and discharged after 2 days |
~30 mL Ethylene glycol (ingested) 33 year male: inebriation, slurred speech, hallucinations, vomiting, unconscious, pale, cyanosis, miosis and failed to react to light, hypotension, nystagmus, fever, and anuria Supportive care, including blood transfusion, nicetamide, sympatol, and strophantin Fatal after 48 to 60 hours ~30 mL Ethylene glycol (ingested) 42 year male: vomiting, pupils failed to react to light, anuria, coma, Kussmaul respiration, hypotension, and absent reflexes Supportive care Fatal after 144 hours 150 mL ethylene glycol windscreen wash solution (ingested) 69 year male: GCS of 6, sluggish pupils, reduced muscle tone, tachypnea, severe metabolic acidosis, elevated BUN, elevated creatinine, increased anion and osmolar gap, anuria, and supraventricular tachycardia. Serum ethylene glycol concentration was 100 mg/dL Supportive care, including intubation, ventilation, IV fluids, sodium bicarbonate, IV ethanol, IV fomepizole, hemofiltration, and amiodarone Recovered and discharged on day 30. 450 mL antifreeze solution (ingested) 60 year old male: coma, Kussmaul respirations, hypotension, hypothermia, hyperglycemia, metabolic acidosis, hyperventilation, hypertension, hypocalcemia, calcium oxalate crystals in urine, aspiration, anuria, elevated creatinine, and seizure Supportive care, including IV saline and glucose, sodium bicarbonate, oxygen, resuscitation, intubation, ventilation, insulin, dobutamine, crystalloid & colloids, epinephrine (adrenaline), norepinephrine (noradrenaline), calcium chloride, mannitol, frusemide, ethanol infusion, hemofiltration, diazepam, and phenytoin Fatal 1,000 mL antifreeze solution (ingested) 48 year male: dysarthria, emesis, hypertension, tachypnea, hypoxia, and increased anion gap. Serum ethylene glycol concentration was 700 mg/dL Supportive care, including oxygen and fomepizole Recovered and discharged after 4 days ~1,900 mL antifreeze and an unknown amount of ethanol (ingested) 33 year male: mildly intoxicated. Serum ethylene glycol concentration was 706 mg/dL Supportive care, including fomepizole Recovered and discharged after 4 days 3,000 mL antifreeze solution (ingested) 36 year male: nausea, vomiting, increased drowsiness, somnolence and became progressively lethargic and bradypneic. Increased anion gap and osmolar gap developed. Urinalysis revealed moderate calcium oxalate crystals. Mild pulmonary edema and non-oliguric acute kidney failure developed after 72 hours. Serum ethylene glycol concentration was 1,889 mg/dL Decontamination and supportive care, including gastric lavage with activated charcoal and magnesium citrate, IV administration thiamine, pyridoxine, magnesium sulfate, sodium bicarbonate, ethanol infusion, and hemodialysis Recovered and discharged after 3 days ~4,500 mL antifreeze solution (ingested) 58 year old male: confusion, metabolic acidosis with increased anion and osmolar gap, decreased BUN, and calcium oxalate crystals in urine. Serum ethylene glycol concentration was 791 mg/dL Supportive care, including activated charcoal, IV ethanol, intubation, and hemodialysis Recovered after 3 to 5 days |
ANIMAL
Ethylene glycol poisoning in animals is relatively common as it has a sweet taste and looks like water. Relatively low amounts of water drained from radiators containing ethylene glycol may cause toxicity. Symptoms in animals are similar to those seen in humans and follow similar stages of toxicity, although excluding the neurological sequelae of poisoning seen in humans. Symptoms in cats and dogs include ataxia, vomiting, diarrhea, disorientation, bradycardia, hypothermia, metabolic acidosis, and acute kidney injury.  In birds, ataxia, weakness, depression, and flaccid paralysis can occur. Calcium oxalate deposits in the renal tubules have also been noted.   In dogs, peak plasma ethylene glycol concentrations occur 2 hours post-ingestion.  Peak glycolic acid plasma concentrations occur at 4 hours.  The sooner antidotal therapy is commenced, the better the outcome.  Cats have the best chance of survival following a lethal dose if the antidote is started within 3 hours of ingestion,  whereas dogs can have the antidote started within 6 to 8 hours of ingestion.  Recovery may take 3 to 5 days.  The antidote is only effective at blocking ethylene glycol metabolism, therefore, there is no benefit of administering it if the ethylene glycol is already metabolized or if the animal has renal failure. Prognosis is poor if the animal presents in the final stage of poisoning, with symptoms of renal failure or coma.  Hemodialysis can be considered in severe cases.  |
LD50 Oral, Rat | 4,000 to 10,020 mg/kg4,000 to 10,020 mg/kg/  |
LD50 Oral, Mouse | 5,500 to 8,350 mg/kg5,500 to 8,350 mg/kg/ |
LD50 Oral, Guinea pig | 6,610 mg/kg6,610 mg/kg/ |
LD50 IP, Rat | 5,010 mg/kg5,010 mg/kg/ |
LD50 IP, Mouse | 5,614 mg/kg5,614 mg/kg/ |
LD50 SC, Rat | 2,800 mg/kg2,800 mg/kg/ |
LD50 IV, Rat | 3,260 mg/kg3,260 mg/kg/ |
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BIOLOGICAL LEVELS - TOXIC
To convert an ethylene glycol concentration expressed in mg/dL into mmol/L: Multiply the mg/dL by 0.1611 To convert an ethylene glycol concentration expressed in mmol/L into mg/dL: Multiply the mmol/L by 6.2070 Units: 1 dL = 0.1 L 1 ug/L = 0.1 ug/dL 1 ug/dL = 10 ug/L |
Toxic Plasma Concentrations |
Plasma Ethylene Glycol Concentration Serum ethylene glycol concentrations at admission are not predictive of outcome. Low serum pH, high anion gap, and low base excess, indicative of accumulation of toxic metabolites, do predict outcome.  Ethylene Glycol Toxic Plasma Concentrations from Case Reports 103 mg/dL (16.5 mmol/L) 1 hour post ingestion) After approximately 120 mL of antifreeze orally, a 13 year old female had ataxia, dysarthria, and calcium oxalate crystals in urine  700 mg/dL (113 mmol/L) time of ingestion unknown After approximately 1,000 mL of antifreeze orally, a 48 year old male had dysarthria, emesis, and metabolic acidosis with a high anion gap  888 mg/dL (143 mmol/L) 3 hours post ingestion After an unknown amount of ethylene glycol was ingested a 28 year old male was comatose with hyperventilation, calcium oxalate crystals in urine, and acute renal failure  1,889 mg/dL (304 mmol/L) 5 hours post ingestion After approximately 3,000 mL of antifreeze orally, a 36 year old male had nausea, emesis, lethargy, bradypnea, metabolic acidosis, calcium oxalate crystals in urine, and acute kidney failure  |
The osmolar gap represents the difference between the measured osmolality (osmoles per kilogram solvent) and calculated osmolarity (osmoles per liter of solution).   When positive, it may indicate the presence of low molecular weight compounds such as alcohols and glycols. A normal osmolar gap does not reliably rule out the presence of a toxic alcohol in the blood stream. OSMOLALITY Serum osmolality is generally in the range 270 to 290 mOsm/kg H2O, and should be measured by freezing point depression.  OSMOLARITY The osmolarity may be calculated using SI units or using Mass (traditional) units. Osmolarity Calculation Using SI Units Osmolarity = 2 x sodium[mmol/L] + glucose[mmol/L] + urea[mmol/L] + ethanol[mmol/L] Urea = BUN (blood urea nitrogen) Include ethanol if found on serum measurement Osmolarity Calculation Using Mass (traditional) Units Osmolarity = (2 x sodium[mEq/L]) + (glucose[mg/dL] /18) + (BUN[mg/dL]/2.8) + (ethanol[mg/dL]/4.6) BUN = urea Include ethanol if found on serum measurement These equations should also include other compounds such as ethanol or mannitol, if present. This calculation should be undertaken in the earlier phases of intoxication prior to the metabolic removal of alcohols and glycols. OSMOLAR GAP CALCULATION Osmolar gap = Measured Osmolality - Calculated Osmolarity The mean normal osmolar gap has been determined to be approximately < 10 or 15 mOsm/kg H2O (though this range will vary between laboratories).  However, there exists considerable variation in osmolar gaps between individuals. Hence, a ‘normal’ osmolar gap does not rule out the presence of an alcohol or glycol.  The osmolar gap is most useful in suggesting the presence of suspected glycol or alcohol ingestion when it is significantly elevated (usually > 20 to 30 mOsm/kg). |
The anion gap represents the difference between the sum of measured cations and the sum of measured anions. An elevated anion gap indicates the presence of unmeasured organic acids (including products of the metabolism of alcohols or glycols). ANION GAP CALCULATION Anion gap = [([sodium]) – ([bicarbonate] + [chloride])] Potassium is normally omitted from the calculation because its range is relatively small and constant. All units should be expressed as mmol/L. A “normal” anion gap may be considered to be within the range of 3 to 15.  |
REPRODUCTION
PREGNANCY
There are limited studies of ethylene glycol in pregnant women. A 26 week pregnant patient who ingested ethylene glycol underwent a cesarean section due to fetal asphyxia. Following birth the neonate was intubated and required artificial lung ventilation. The child had metabolic acidosis and was treated with forced diuresis and replacement transfusion. The baby was extubated at 2 weeks and discharged after 3.5 months with no significant neurological complications.  Pregnant female workers potentially exposed to industrial mixtures containing ethylene glycol ethers had increased risk of spontaneous abortion and subfertility.  In animal studies the metabolite glycolic acid is responsible for developmental toxicity in rats rather than ethylene glycol itself.  Low level exposures of ethylene glycol do not saturate glycolic acid metabolism so have a low risk of development effects.  Both ethylene glycol and glycolic acid decreased fetal body weights and axial skeleton malformations in rats.  Ethylene glycol has been shown to be teratogenic in animals. Teratogenicity was observed in the absence of maternal toxicity in both rats and mice. Effects in mice include reduced number of live pups, decreased pup weight, and skeletal malformations (fused ribs, abnormally-shaped or missing vertebrae, and twisting of the spine).  Similar effects were noted in rats receiving doses of 2,500 to 5,000 mg/kg/day.   At these doses, severe malformations including craniofacial abnormalities, neural tube defects (anencephaly, meningomyelocele), and visceral malformations were observed.  |
LACTATION
It is unknown whether this compound is excreted in human breast milk. |
TOXIC MECHANISM
The major toxic agent in ethylene glycol poisoning is not the parent compound, but the metabolites produced by the action of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). Ethylene glycol is rapidly metabolized via ADH into glycoaldehyde, which is rapidly converted into glycolic acid by ALDH. The rate-limiting step in the metabolism of ethylene glycol is the formation of glyoxylic acid from glycolic acid via lactate dehydrogenase or glycolic acid dehydrogenase. Glyoxylic acid can be either metabolized into non-toxic alpha-hydroxy-beta ketoadipate and glycine via thiamine and pyridoxine-dependent ways respectively, or into oxalate.  The etiology and pathophysiology of the CNS, metabolic, cardiopulmonary, and renal toxicity are primarily due to the formation and accumulation of toxic intermediary metabolites, especially glycolic acid (produces metabolic acidosis) and to a lesser but histologically important extent, oxalate production, and excretion.  Calcium oxalate crystals may form in tissues, in particular the renal tubules, lungs, and the meninges of the brain, and excreted in the urine.  |
KINETICS
ABSORPTION
Onset of Action CNS effects may occur within 30 minutes Time to Peak Plasma Levels 1 to 4 hours |
DISTRIBUTION
Volume of Distribution - During hemodialysis: 0.5 to 0.67 L/kg
 
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METABOLISM
Metabolism - Hepatic

Major Metabolic Pathways Parent: - Via alcohol dehydrogenase to glycoaldehyde
 
Glycoaldehyde : - Metabolized to glycolic acid with subsequent conversion to glyoxylic acid and oxalate
 
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ELIMINATION
Excretion Urine - 20% excreted unchanged in urine
 
Potential for Accumulation - Calcium oxalate crystals can accumulate in the kidney leading to renal damage and renal failure

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IDENTIFICATION
OTHER NAME(S)
1,2-Ethaandiol | 1,2-Ethandiol | 1,2-Ethanediol | 2-Hydroxyethanol | Antifreeze | Athylenglykol | Coolant | Deicer | EG | Etandiol | Ethane-1,2-diol | Ethylene alcohol | Ethylene dihydrate | Ethylene glycol | Ethylenglycol | Etilenglicol | Etilenglikol | Etilenoglicol | Etyleeniglykoli | Glicole etilenico | Glikol etylenowy | Glycol | Glycol alcohol | Glycolmonomer | Lutrol-9 | M.E.G | Monoethylene glycol | Radiator fluid | Ramp | Ucar 17 |
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Ethylene Glycol: 1,2-Ethanediol |
Do Not Archive. This document is current on day of issue,
NZ: 23.May.2022 |