Formaldehyde (E240)

The name “formaldehyde” at least once in a lifetime has been heard by every person. The substance has a wide range of applications – from furniture production to the food industry, and the consumer is faced with it every day, without even realizing this fact. Formaldehyde is given the code designation “E240”, it was previously called formic aldehyde or formic acid aldehyde, and internationally it has the name “methanal”. This additive, although it is present in the classifications of food additives, cannot be used in food because of its high carcinogenicity and strong negative effect on the human body. However, unscrupulous manufacturers are not always ready to give up this powerful preservative and antiseptic.

Properties of the substance and the mechanism for its production

Formaldehyde belongs to the homologous series of aliphatic aldehydes. In its normal state, it is a colorless gas with a pungent, irritating odor. Formaldehyde may contain impurities of formic acid, various polymers and methanol. In water and alcohols, the substance has good solubility. It is an aqueous solution of formaldehyde called formalin and is often used for medical purposes. Also, the E240 additive can polymerize, sometimes randomly, acquiring a solid form and turning into trioxane, polyformaldehyde, paraformaldehyde or tetraoxane. At a temperature of 19,2 degrees Celsius, the substance begins to boil, and at 118 degrees Celsius, it melts. 435 degrees – self-ignition temperature.

It is precisely because of the tendency to polymerization in the industrial field that it is used more often in the form of solutions – aqueous (up to 10%) or alcohol (in 10% alcohol up to 37%), or bound in compounds in the form of paraformaldehyde or hexamethylenetetramine. The latter undergo dilution and reaction with acid, as a result of which formaldehyde is released.

Industrial production of additives occurs in laboratory conditions by the oxidation of methanol or methane. The reactions take place at elevated pressure, high temperature and using catalysts.

As of 2015-2016, about 8,8 million tons of formaldehyde were produced in the world. About 38 percent of all methanol in the world is consumed for this purpose. Most of the production is in Europe and the United States of America. The leaders in this industry are Dynea, Nexion Specialty Chemicals, BASF.

Additive E240 is valued as a powerful preservative and antiseptic, capable of destroying a significant number of types of pathogenic microorganisms and their spores, thereby increasing the shelf life of products.

Formaldehyde in nature

A rather dangerous and toxic substance methanal is found in wildlife. The element is one of the components of the metabolic process, as it is associated with the exchange of tetrahydrofolic acid derivatives in the body. At the same time, in the human body, it is neutralized by oxidation, after which it is excreted by the kidneys.

In addition, methanal is also present in the atmosphere, its concentration is especially high over large cities. There are several sources of its appearance in the air:

• photochemical reactions of methane in the layers of the atmosphere;
• fires in cities, forests, peat bogs;
• household and industrial dumps;
• release of formaldehyde from materials containing it (for example, chipboard boards);
• emissions from enterprises that work with the substance.

After rains, as well as in winter, the concentration of formaldehyde in the air naturally decreases.

In the natural environment, the substance is absorbed by methanotrophic bacteria that live in water bodies and soils.

Tobacco smoke, some types of natural wines, vegetables and fruits, beer and cognacs can also release methanal into the environment.

Additive E240 – to help a person

Back in the 20th century, a significant portion of formaldehyde was consumed by the food industry. To date, the balance has shifted towards the chemical industry: it is used for the production of various types of resins (phenol-formaldehyde, melamine-formaldehyde and others). Resins, in turn, are used as an element for the manufacture of particle boards and fibreboards, phenolic and aminoplasts, abrasives, varnishes, adhesives, coatings and primers.

Many chemicals, for example, urotropine, etriol, pentaerythritol, are also produced on the basis of methanal.

Despite strict bans, some food industry corporations still produce products with the addition of E240 in the composition, for example:

• sausages;
• sausages;
• cheeses;
• Smoked products;
• fish and meat preserves.

In Russia, about 10 years ago, the use of E240 as a defoamer and antiseptic in the processing of sugar beet, as well as for the manufacture of yeast, was still allowed.

Formalin is a substance widely used in medicine and biology: due to the fact that the solution has the property of protein coagulation, it is used to preserve biological material, disinfect surfaces and tools.

There are drugs with formaldehyde in the following forms:

• ointments;
• solutions;
• powders;
• vaccines.

In personal hygiene products, the preservative E240 is present as a component that does not allow the development of pathogenic microflora. It can be found in shampoos, shower gels, and detergents. For the same purpose, it can be used in cosmetics, nail care products, and oral products.

Formaldehyde is used to tan gelatin to make film.

Features of containers for storing additives E240

Formaldehyde is most often transported and stored as a solution rather than a gas. For these purposes, glassware is used, for example, bottles, as well as barrels and tanks made of stainless steel. For some metals, formaldehyde causes corrosion, and this fact must be taken into account when choosing a packaging material for it.

Regulatory requirements for the release of a substance from various materials

The international community has settled the issue of rationing the emission of formaldehyde vapors in relation to formaldehyde-containing elements, defining three classes of safety requirements for such emissions: E1, E2, E3. For example, for furniture, the most stringent class of requirements E1 is established – that is, in the manufacture of materials for its production, the amount of methanal cannot exceed 10 mg per 100 g of dry raw materials for Russia, or 8 mg for Europe, respectively, and the release of toxic fumes should be insignificant.

The high content of formaldehyde resins in materials such as particle boards and fibreboards makes them more durable, but also highly toxic. Today, furniture manufacturers offer consumers another option for raw materials – MDF or medium density fibreboard. The content of hazardous resins in them does not exceed the norm due to some specifics of the production process.

The maximum allowable amount of methanal in the air is also regulated by the norms of the international community and each specific state. For example, the requirements for Russia are established by the Hygienic Standards. They indicate that a single concentration for settlements should not exceed 0,035 mg per 1 cubic meter of air, and the permissible average daily concentration cannot be more than 0,003 mg per 1 cubic meter.

Human exposure: formaldehyde poisoning and other hazards

According to the results of research by the World Health Organization, the E240 additive cannot come into contact with food at all, as it has a strong toxic, allergic and oncogenic effect. Vapors of formaldehyde affect the mucous membranes of the nasopharynx in such a way that malignant tumors begin to form in them. In addition, methanal has a negative effect on the blood, which can cause anemia and leukemia.

The lethal dose of formaldehyde for humans is half a teaspoon of an aqueous solution.

In addition, with constant inhalation of formaldehyde vapors from the air, for example, when smoking, a person may develop symptoms of poisoning that are chronic: nausea, headache, weakness, apathy, blurred vision, tremor of the limbs.

The additive is extremely dangerous for children, pregnant and lactating women, asthmatics and allergy sufferers, as well as people who suffer from respiratory diseases. However, for completely healthy owners of a strong body, formaldehyde and its vapors are very harmful.

Additive E240, formaldehyde or methanal is still in the international classifications of food additives, although it is strictly forbidden to use it for food preparation in almost all countries of the world. A strong carcinogen, allergen and toxin can greatly undermine health not only through food, but also through the use of furniture and various chemicals in which it is contained. Formaldehyde resins, although widely used in the chemical industry, are also not safe for humans.