India, Oct. 5 -- At least nine children have died in a Madhya Pradesh district after allegedly consuming contaminated cough syrup. As authorities ban syrup brands and investigate the source of contamination, the tragedy has thrust two dangerous substances-diethylene glycol (DEG) and ethylene glycol (EG)-back into the spotlight. With nine children dead in Chhindwara allegedly from contaminated cough syrup, two industrial chemicals-diethylene glycol (DEG) and ethylene glycol (EG)-are once again at the centre of a public health crisis. This is not the first time these toxic substances have caused mass poisonings in India and globally. Diethylene glycol and ethylene glycol are colourless, viscous liquids with a sweet taste. They are commonly used in industrial products such as antifreeze, brake fluids, paints, and stationery ink. Both substances are highly toxic to humans and have no legitimate use in medicines. According to the US Centers for Disease Control (CDC), DEG and EG are often found as contaminants in glycerin, which is used as a sweetener in many pharmaceutical syrups. The CDC notes that "complexities in the distribution of glycerin and other pharmaceutical raw materials that may involve many handlers (importers and exporters)" allow these contaminants to enter glycerin-based medical products. DEG has also been used illegally as a cheap substitute solvent in drug manufacturing due to its similar physical properties to safe pharmaceutical ingredients. Inadequate international regulations and lack of analytical testing methods contribute to such adulteration, according to scientists. The toxic effects include abdominal pain, vomiting, diarrhoea, bladder dysfunction, headache, altered mental state, and acute kidney injury. The contaminants cause renal and neurological toxicity-affecting kidney and brain functions. Acute kidney injury is usually the main cause of death, which can occur anywhere between 8 and 24 hours after exposure if the dose is high. Far from it. Mass poisonings from DEG date back to 1937, when 105 people died in the US from DEG poisoning, prompting the passage of stringent legislation in 1938, according to research published by the World Health Organization. In India, 14 patients died in Mumbai in 1986 after being given glycerin contaminated with DEG. A second episode occurred in 1998, killing at least 33 children, according to local accounts and WHO. More recently, WHO issued alerts in 2023 regarding India-made cough syrups linked to deaths in The Gambia and Uzbekistan. Laboratory analysis confirmed "unacceptable amounts of diethylene glycol and ethylene glycol as contaminants" in those products. While trace amounts of these contaminants are sometimes found in glycerin-based medicines, WHO's 2023 alert specified that the contamination levels in the implicated products were "unacceptable amounts"-suggesting there are threshold limits that were dangerously exceeded....