What Is Ethylene Oxide, The Harmful Carcinogen Reportedly Found In MDH, Everest Spices?

Singapore, Hong Kong, the European Union and the Maldives have raised concerns over a cancer-causing chemical called ethylene oxide in Indian food products, especially spices. The European Food Safety Authority (EFSA) conducted tests on different food items over the course of 3 and a half years, between September 2020 and April 2024, and found that more than 527 products exported from India had ethylene oxide.

What is Ethylene Oxide?

Ethylene oxide (EO) is a highly reactive compound with a wide range of industrial applications. According to the National Cancer Institute of The USA, at room temperature, ethylene oxide is a flammable colourless gas with a sweet odour. It is used primarily to produce other chemicals, including antifreeze. In smaller amounts, ethylene oxide is used as a pesticide and a sterilizing agent. Despite its usefulness, ethylene oxide poses significant risks to human health, both in the short and long term. Understanding its history, development, uses, and associated health risks is crucial for ensuring safety in workplaces and communities where ethylene oxide is present.

History and development

Ethylene oxide was first synthesised in 1859 by the French chemist Charles-Adolphe Wurtz. However, its industrial significance grew in the early 20th century with the development of the chlorohydrin process, which allowed for large-scale production. During World War I, ethylene oxide gained prominence as a precursor in the production of mustard gas, a chemical weapon.

After the war, ethylene oxide found commercial applications in the sterilisation of medical equipment, fumigation of agricultural products, and as a precursor in the production of various chemicals, including ethylene glycol, which is used in antifreeze and polyester manufacturing.

Uses of Ethylene Oxide

Ethylene oxide is primarily used as a sterilant for medical equipment due to its ability to penetrate packaging and kill microorganisms, including bacteria, viruses, and fungi. It is also employed in the production of plastics, textiles, detergents, and solvents. Additionally, ethylene oxide is used in the fumigation of food products to control pests and microbial contamination.

Health Risks

There are many short-term and long-term associated with the now infamous ethylene oxide

Short-term health risks

Exposure to ethylene oxide in the short term can cause irritation of the eyes, skin, and respiratory tract. Symptoms may include coughing, wheezing, chest tightness, nausea, and headache. Acute exposure to high concentrations of ethylene oxide can result in chemical burns and pulmonary edema, a life-threatening condition characterised by fluid accumulation in the lungs.

Long-term health risks

Long-term exposure to ethylene oxide has been linked to serious health effects, including cancer. The International Agency for Research on Cancer (IARC) classifies ethylene oxide as a known human carcinogen, particularly associated with an increased risk of leukaemia, lymphoma, and breast cancer. Chronic exposure to low levels of ethylene oxide has also been associated with reproductive and developmental effects, including miscarriage, infertility, and birth defects.

Mechanism of carcinogenicity

Ethylene oxide is classified as a genotoxic carcinogen, meaning it can damage DNA and induce mutations in cells. Upon entering the body, ethylene oxide is metabolised into reactive intermediates that can react with DNA, leading to the formation of DNA adducts and strand breaks. These DNA lesions can disrupt normal cellular processes, promote uncontrolled cell growth, and ultimately contribute to the development of cancer.

Furthermore, ethylene oxide has been shown to interfere with DNA repair mechanisms, exacerbating its genotoxic effects. Additionally, ethylene oxide-induced mutations in critical genes, such as tumour suppressor genes and oncogenes, can disrupt cellular signalling pathways involved in cell cycle regulation and apoptosis, further promoting carcinogenesis.

The reservations regarding Ethylene Oxide

As per regulations by The European Union, only 0.05 milligrams per kilogram of ethylene oxide is allowed in Europe. And the ban on Indian food products suggests that the food items were exceeding those limits. A similar case had also come to light in September 2020, when high levels of pesticides were found in 268 tonnes of sesame seeds from India. The contamination had a level of 1000 to 3500 times the limit of ethylene oxide allowed in Europe.

The recent developments have casted a shadow of doubt over the quality of spices we not only export, but consume. The Union Commerce Ministry has sought details from the food safety organisations of Singapore and Hong Kong along with directing Indian embassies in both countries to submit a detailed report.

The spice-making companies MDH and Everest, whose products have been banned for containing carcinogenic ethylene oxide beyond permissible limits, have also been asked to send details. Both the companies have denied the allegations and claimed that their spices pass the strictest quality checks.