Diethylene glycol

Diethylene glycol
IUPAC name	(2-hydroxyethoxy)ethan-2-ol
Other names	diethylene glycol; ethylene diglycol; diglycol; 2,2'-oxybisethanol; 3-oxa-1,5-pentanediol; dihydroxy diethyl ether
Identifiers
CAS number	111-46-6 Y
PubChem	8117
SMILES	OCCOCCO
Properties
Molecular formula	C4H10O3
Molar mass	106.12 g/mol
Appearance	Colorless liquid
Density	1.118 g/mL
Melting point	-10.45 °C
Boiling point	244-245 °C
Solubility in water	miscible
Hazards
MSDS	Diethylene-glycol MSDS
Related compounds
Related diols	ethylene glycol, triethylene glycol
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Diethylene glycol (DEG) is an organic compound described by the structural formula HO-CH₂-CH₂-O-CH₂-CH₂-OH. It is a clear, hygroscopic, odorless liquid. It is miscible with water and polar organic solvents such as alcohols and ethers.

Diethylene glycol should not be confused with the related compound, ethylene glycol, which is the most common glycol used in coolants.

Diols and polyols

Diethylene glycol is one of several diols (hydrocarbon containing two alcohol groups). Diols related to diethylene glycol are derived from ethylene oxide and are described with the formula HO-CH₂-CH₂(-O-CH₂-CH₂)_n-OH:

• n = 0 ethylene glycol ("antifreeze")
• n = 1 DEG
• n = 2 triethylene glycol, TEG, or triglycol
• n = 3 tetraethylene glycol
• n = 4 pentaethylene glycol
• Higher numbers for n describe a non-toxic polymer called polyethylene glycol.

Uses

DEG is used as a building block in organic synthesis, e.g. of morpholine and 1,4-dioxane. It is a solvent for nitrocellulose, resins, dyes, oils, and other organic compounds. It is a humectant for tobacco, cork, printing ink, and glue.^[1] Like ethylene glycol, a solution of diethylene glycol and water is used as a coolant. It slightly lowers the freezing point of the solution and significantly elevates its boiling point, making it more suitable for use in hot climates. It can be also found in some hydraulic fluids including brake fluids.^[2] In personal care products (e.g. skin cream and lotions, deodorants) DEG is often replaced by selected diethylene glycol ethers.

Diethylene glycol is also illegally used as counterfeit glycerin in some nations and sold internationally as a component of cough syrup, toothpaste, and mouthwash.^[3] It has in the past been used as an adulterant by winemakers to create a "sweet" wine.^[4][5]

Toxicity

Diethylene glycol has moderate acute toxicity in animal experiments. The LD₅₀ for small mammals has been tested at between 2 and 25 g/kg, less toxic than its relative ethylene glycol but still capable of causing toxicity in humans. Several epidemics of poisonings have occurred when DEG was substituted for the non-toxic naturally occurring "triol" glycerine (also called glycerol) or propylene glycol in foodstuffs and pharmaceuticals. It appears diethylene glycol is more hazardous to humans than implied by oral toxicity data in laboratory animals.^[2] Because of its adverse effects on humans, diethylene glycol is not allowed for use in food and drugs. The U.S. Code of Federal Regulations allows no more than 0.2% of diethylene glycol in polyethylene glycol when the latter is used as a food additive.^[6]

Epidemiology

DEG has been involved in numerous cases of poisonings, both by accidental and deliberate introduction of the compound into medicines, food products and toothpaste.^[2] The earliest example of mass poisoning was the 1937 Elixir Sulfanilamide incident in the USA.^[7][8] 107 people died after they ingested sulfanilamide dissolved in diethylene glycol.^[9] This episode was the impetus for the Federal Food, Drug, and Cosmetic Act of 1938.^[10]

In recent years, deaths from medicines adulterated with diethylene glycol have been reported from South Africa,^[11] Spain,^[12] India,^[13] Nigeria,^[14] Argentina,^[15][16] Haiti,^[17] Bangladesh^[18] and Panama.^[19] In Haiti in 1996, 85 children died due to glycerine contaminated with diethylene glycol in a paracetamol syrup produced by Pharval Laboratories, a Haitian company, which did not use standard quality assurance procedures to verify the purity of the glycerine. The glycerine supplied by a Dutch company, Vos, from a manufacturer in China, but the point of contamination with DEG was never determined.^[17] In Bangladesh between 1990 and 1992, 339 children developed kidney failure, and most of them died, after being given paracetamol (acetaminophen) syrup contaminated with diethylene glycol.^[18] In October 2006 the CDC and the Ministry of Health of Panama detected toxic levels of diethylene glycol in a sugarless liquid expectorant during an investigation of 46 deaths. Almost all the victims were hypertension and diabetes patients in their 40s to 80s. The source of the contamination was found to be the Taixing Glycerine Factory, a Chinese company in Hengxiang, China. Taixing Glycerine sold diethylene glycol labeled as TD glycerine, which is an industrial name, through the state-owned Chinese trading company CNSC Fortune Way, based in Beijing. A Spanish middleman ordered these as TD glycerine, but when filled the custom declaration the name was changed to glycerine.^[20][21] A government agency in Panama purchased the falsely labeled product containing diethylene glycol and incorporated it into 260,000 bottles of cold medicine.^[22][23] The United States Food and Drug Administration issued an Industry Guidance Document highlighting appropriate testing procedures for use of glycerin in response to product contamination and misrepresentation.^[24]

In May 2007, a Panamanian named Eduardo Arias discovered that toothpaste sold in his country was labeled as containing DEG, the same ingredient that had tainted cough syrup and killed 138 Panamanians in 2006. Panamanian officials discovered that the toothpaste had come from China and initiated a global response.^[25][26][27] Also in May 2007 the same toothpaste was found in some Costa Rican stores. Fast action by the Ministry of Health, and notification through the media, prevented poisonings due to this product. This event was linked to the death sentence of a former pharmaceuticals control officer in China, as the Costa Rican newspaper La Nación reported on its issue of May 30th.^[28] On June 4, 2007, a press release by the Chinese Foreign Ministry^[29] cited an earlier study in China^[30] which concluded that up to 15.6% diethylene glycol in toothpaste is safe. In June 2007, counterfeit Colgate toothpaste imported from China was found to be contaminated with DEG, and several people in eastern US reported experiencing headaches and pain after using the product.^[31]. The same occurred in Spain with a false Colgate toothpaste, which contained 6% DEG. The tainted products could be identified by the claim to be manufactured in South Africa by Colgate-Palmolive South Africa LTD; they were 5oz/100ml tubes (a size which Colgate does not sell in the United States) and their packaging contained numerous misspellings on the labels. Colgate-Palmolive claimed that it does not import their products from South Africa into the United States or Canada and that DEG is never and was never used in any of its products anywhere in the world. These counterfeit products were found in smaller mom and pop stores, dollar stores and discount stores in at least four states.^[32] In July 2007, diethylene glycol was found in counterfeit Sensodyne toothpaste, on sale at a car boot sale in Derbyshire, England,^[33] and by February 2009, 84 Nigerian children were reported to have died after being given "My Pikin", a teething syrup contaminated with diethylene glycol.^[34]

Symptoms

The symptoms of poisoning typically occur in three characteristic intervals.^[2] Initial symptoms include nausea, vomiting, diarrhea, inebriation, and drowsiness. This is followed by a second stage consisting of metabolic acidosis and liver and kidney damage. The second phase normally develops 1 to 3 days after ingestion and may lead to acute kidney failure and death. If the second stage is survived the third stage develops 5 to 10 days post-ingestion and symptoms displayed are mainly neurological including lethargy, facial paralysis, dysphonia, dilated and nonreactive pupils, quadriplegia, and coma. Poisoned people may suffer permanent brain damage in the final stage.^[2]

References

References

• Merck Index, 12th Edition, 3168.

See also

• Polyethylene glycol

External links

• Diethylene Glycol
• The Elixir Sulfanilamide Disaster