Understanding the Importance of Ethylene Oxide Residue Testing

Introduction

Ethylene oxide (EO) is a highly versatile chemical used in various industrial processes, including the sterilization of medical equipment and as a precursor in the production of other chemicals. However, concerns arise regarding its potential residual presence and associated health risks, prompting rigorous testing and regulation.

What is Ethylene Oxide?

Ethylene oxide is a flammable, colourless gas with a slightly sweet odour. It is soluble in water and organic solvents, making it useful in sterilization processes, particularly in healthcare settings. Its ability to penetrate various materials makes it effective in ensuring the sterility of medical devices that cannot be sterilized by steam.

Exposure of ethylene oxide residue in foods

Ethylene oxide can enter food products through various sources and types of exposure. Here are some of the common sources of ETO in food products:

Source of ETO	Description	Potential Contamination
Fumigation	ETO gas is used to kill bacteria, microorganisms, and pests in sealed containers. Common for spices, dried herbs, and dried food products.	Residual ETO can remain in treated items and contaminate food.
Pesticides	ETO is employed as a fumigant in storage areas to control pests.	Can potentially lead to contamination of grains and other stored food products.
Sterilization of Packaging	ETO is used to sterilize food packaging materials like plastic containers, pouches, and bags.	Residual ETO in the packaging can migrate into the food product, leading to contamination.
Processing Aids	ETO is used to modify physical and chemical properties of food ingredients like starch and gums.	Can result in potential contamination of the final food products.
Medical Equipment Sterilization	ETO is commonly used to sterilize medical devices and equipment.	Improper handling or disposal of sterilized equipment can lead to ETO contamination of food processing areas.

Residue Concerns and Health Risks

Despite its efficacy in sterilization, ethylene oxide poses health risks due to its toxic properties. Prolonged exposure to high concentrations has been linked to respiratory issues, neurological effects, and even cancer. Concerns primarily revolve around the potential residue left on sterilized products, which could leach into the environment or be absorbed by users.

Why ETO Has To Be Tested?

Due to the mutagenic properties, International Agency for Research on Cancer (IARC) classified ETO as a human carcinogen. Ethylene oxide may also form ethylene glycol (EG) and ethylene chlorohydrin (ECH) during chemical reactions, which are also toxic.

Exposure to ETO can cause:

Irritation to the eyes, skin and respiratory tract
Nausea and vomiting
Central nervous system depression
Chronic exposure is associated with an increased risk of cancer.

If food sterilised with Ethylene Oxide is not aerated properly, ETO residue can remain. This can lead to the formation of 2-Chloroethanol, another toxic compound that is capable to cause damage to the heart, liver and kidneys as well as respiratory failure. Exposure to 2-Chloroethanol can sometimes led to death.

Regulations and standards

Regulation	Key Points
Regulation (EU) 2020/1540	Monitoring EO and 2-CE residues in foods
Regulation (EU) 2021/2246	Increased controls for EO residue entry
Regulation (EU) 2019/1793	Addresses EO residues in Indian sesame seeds
Regulation (EC) No 396/2005	Sets MRL of 0.05 mg/kg for EO in foods
Regulation (EU) 2015/868	Sets MRLs for EO and 2-CE in various foods
FSSAI (India)	Prohibits EO fumigation due to health risks
U.S. EPA	Classifies EO as a carcinogen and sets inhalation unit risk

Mandatory and Optional Analyses for Ethylene Oxide (ETO) Testing in Foods

There are currently two main categories of analyses for ETO testing in food, depending on regulations and specific needs:

Mandatory Analyses:

Total Ethylene Oxide and its Metabolite 2-Chloroethanol: This is the mandatory analysis in most cases. Regulations like EU's Regulation (EC) No. 396/2005 set the Maximum Residue Limit (MRL) for the combined amount of ETO and its breakdown product, 2-Chloroethanol. This analysis ensures compliance with such regulations.

Optional Analyses:

Individual Analysis of Ethylene Oxide: While some regulations focus on the combined amount, some testing facilities might offer separate analysis for ETO itself. This can be useful for pinpointing the source of contamination.
Analysis of Other ETO Breakdown Products: ETO can break down into other compounds besides 2-Chloroethanol. Optional analyses can target these additional breakdown products for a more comprehensive picture of potential contamination.
Moisture Content: Moisture content in food can affect the detection limits of ETO analysis. Knowing the moisture content can help interpret the results more accurately.

Eurofins role in ethylene oxide residue testing

Eurofins plays a significant role in Ethylene Oxide (ETO) residue testing for food products. Here's a breakdown of their involvement:

Pioneering Analytical Methods: Eurofins scientists in Germany are credited with developing the current method for detecting ETO in food . This method involves converting ETO into a detectable compound and then measuring it using a highly sensitive technique.
Advanced Testing Capabilities: Their labs possess advanced equipment like Gas Chromatography-Mass Spectrometry (GC-MS/MS) to detect even trace amounts of ETO residue (as low as 0.01 mg/kg) .
Extensive Food Matrix Testing: Eurofins can analyze a wide variety of food products, including raw materials, processed foods, and novel ingredients, for ETO contamination .
Global Reach: With a network of laboratories across multiple countries, Eurofins offers ETO testing services on a large scale .
Regulatory Expertise: They can advise clients on relevant regulations and help determine the appropriate testing needs based on the specific food product .