Thiabendazole (E233)

When buying beautiful, eye-catching foreign fruits – oranges, lemons, bananas, few people think about how they retained their taste, color and freshness on the way to the consumer. In their natural state, the fruits could turn into a rotting pile along the way, but for companies involved in the sale and supply of fruits and vegetables, this option, of course, can only bring losses. Therefore, in order for an exotic product to reach markets and supermarket shelves without loss, it is subjected to surface treatment with various fungicides and preservatives. Among them is thiabendazole or food additive E233.

Chemical characteristics and mechanism for obtaining a substance

Thiabendazole is a surface preservative of low toxicity, which belongs to the group of benzimidazoles. It has a depressing effect on the growth and spread of bacteria and fungi, which can provoke decay processes. It has such a powerful effect that even in very small concentrations it is able to successfully fight unwanted microorganisms. It is as a preservative that it is most often used in the food industry. As a fungicide and antibacterial agent, it is valued by veterinarians, physicians and farmers.

In appearance, the additive is a white crystalline powder. The substance has no taste and smell. A light yellow or cream shade is allowed, as the structure may contain impurities. In water, the substance dissolves poorly, normally – in acidified water, in alcohols and ether. The additive is also characterized by high thermal stability. In aqueous, acidic and alkaline solutions it is stable, and at a temperature of 296 degrees Celsius it begins to melt.

In addition to the name “thiabendazole”, the E233 supplement is known as mintezol (a name common in trade in the medical market), as tetusim, mertekt or arbotect (in the agricultural sector), as faldan, anastrongyl or vermobial (in the livestock sector).

The production of the substance occurs as a result of a chemical reaction: orthophenidiamine is condensed with thiazolecarboxylic acid using an acid catalyst and at elevated temperature. The resulting element is precipitated with alcohol. In wildlife, thiabendazole does not occur, that is, it is a synthetic, artificially obtained element.

Containers for storage and transportation E233: basic requirements

The substance can have not only a powder form, it is also produced in the form of aqueous solutions, ointments, tablets.

In a dry state, for example, for the needs of agriculture, thiabendazole is packaged in the following types of packaging:

  • polypropylene or multilayer paper bags;
  • cardboard drums;
  • plastic barrels.

The aqueous solution is contained in plastic sealed canisters.

For use in animal husbandry and veterinary medicine, the additive is packaged as a 75% dispersed powder in plastic bags.

Human use of the substance

In Russia, the states of the European Union, the USA and Canada, the use of thiabendazole in food products is prohibited. Suppliers of exotic fruits and vegetables treat fruits, especially citrus fruits and bananas, with an aqueous solution of a substance. By the way, such chemical “pollination” for the crop is carried out twice – before it is separated from the branches, and already before packaging for shipment. Usually the company that is responsible for picking and packing the fruit must state on the label that it has been processed with E233.

A small amount (up to 12% of the substance) can enter the pulp through the peel, but such a dosage is not toxic, dangerous or harmful to humans.

In agriculture, thiabendazole is used as:

  • means for combating diseases of cereals, berries, onions, champignons, sunflowers (effective against stem rot, powdery mildew, nematode and some other diseases);
  • component of grapevine treatment against gray rot;
  • a substance effective against infection of potatoes with rhizoctoniosis, and for root crops of carrots and beets – against phomosis;
  • protection against rot of greenhouse plants (stems, roots, leaves, flowers, fruits are “fumigated” with them);
  • ingredient of the mixture for the treatment of “wounds” of trees – damage and sections of the bark.

Crops can also be exposed to the substance – in this way, crops in storage can be protected from spoilage and rot.

The animal husbandry and veterinary industries have appreciated the antimicrobial and antiparasitic properties of thiabendazole, which is why it is a component of some anthelmintic drugs for animals. The additive affects the parasites produced by a helminth-specific enzyme – fumarate reductase, which has a negative effect on the body of adults, and they begin to die. Also, E233 can inhibit the ability to reproduce and the growth of already existing parasite larvae.

The substance contributes to the suppression of pathogenic flora in the digestive tract and has a positive effect on fat metabolism in poultry, cattle and sheep. Its use allows you to increase the volume of milk yield. At the same time, meat and milk obtained from animals to which the additive was used do not contain it. E233 is also included in some antilichen ointments for animals.

For medical purposes, thiabendazole is used as an ingredient in skin disinfectants, as an active ingredient in the treatment of helminths, as an antidote, and as part of active therapy for the treatment of heavy metal poisoning, such as mercury.

Winemakers use the E233 additive as an element to stop the fermentation processes of wine material.

Impact on human health

A small amount of thiabendazole (up to 5%) is absorbed by the intestines, the rest is excreted unchanged by the kidneys. In large doses, the substance can have a toxic effect on the body, with the corresponding symptoms: vomiting, nausea, indigestion, headaches, lack of appetite, drowsiness, fever, dark urine. Direct contact of the skin and mucous membranes with the additive in its pure form leads to skin diseases, the appearance of allergic reactions.

The average daily intake for an adult is 0,3 mg of E233 supplement per 1 kilogram of weight. More than 3 g of a substance per day is considered an overdose.

The lethal dose is 3,6 g per 1 kilogram of weight, and when taking an amount of the supplement close to this value, disturbances in the processes in the liver cells begin, and reproductive function may suffer.

Scientists do not yet have any information about the possible oncogenicity or mutagenicity of thiabendazole. Moreover, there is evidence that the substance, on the contrary, can slow down the growth of malignant tumors. While this property continues to be studied, and no official statements have been made about this.

In Ukraine, Russia and the countries of the former CIS, the additive under the code E233 is treated with caution, rarely using it even to treat people or animals from parasites. The main part of the substance goes to the share of agriculture, as a pesticide. It is not possible to use thiabendazole for food products in these states and EU countries.

Interestingly, when the fruit treated with the additive gets into the hands, about 15% of its amount from the skin remains on the hands. Therefore, both your favorite tangerines and sunny bananas with oranges should be washed very thoroughly under warm running water before use so that chemicals from the surface of the fruit or vegetable do not enter the body.

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