The name “formaldehyde” was heard at least once in a lifetime 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 assigned the code designation “E240”, formerly it was called formic aldehyde or formic acid aldehyde, and at the international level it is called “methanal”. This supplement, although it is present in the classifications of food additives, cannot be used in food products because of its high carcinogenicity and strong negative effect on the human body. However, unscrupulous manufacturers are not always ready to abandon this powerful preservative and antiseptic.
Properties of the substance and the mechanism of its production
Formaldehyde refers to the homologous series of aliphatic aldehydes. In its normal state, it is a colorless gas with a pungent, annoying 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 arbitrarily, acquiring a solid form and passing 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 - autoignition temperature.
It is because of the tendency to polymerization in the industrial sphere that it is used more often in the form of solutions - aqueous (up to 10%) or alcohol (in 10 percent alcohol up to 37%), or bound in compounds in the form of paraformaldehyde or hexamethylenetetramine. The latter are diluted and reacted with acid, resulting in the release of formaldehyde.
Industrial production of the additive occurs in laboratory conditions by the oxidation of methanol or methane. 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 the world's total methanol is consumed for this purpose. Most of the production comes from 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 that can destroy a significant number of species of pathogenic microorganisms and their spores, thereby increasing the shelf life of products.
Formaldehyde in nature
A sufficiently 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 tetrahydrofolate acid derivatives in the body. Moreover, 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 atmosphere;
- fires in cities, forests, peat bogs;
- domestic and industrial landfills;
- the release of formaldehyde from materials containing it (for example, chipboard);
- 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, fruits and vegetables, beer and cognac can also release methanal into the environment.
Additive E240 - to help people
Back in the 20th century, a significant portion of formaldehyde was consumed by the food industry. Today, 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 chipboard and fiberboard, phenolic and amino plastics, grinding materials, varnishes, adhesives, coatings and primers.
Many chemicals, such as urotropine, etriol, pentaerythritol, are also produced on the basis of methanal.
Despite the strict prohibitions, some corporations in the food industry still produce products with the addition of E240 in the composition, for example:
- smoked meats;
- canned fish and meat.
About 10 years ago in Russia, the use of E240 as an antifoam and antiseptic in the process of processing sugar beets, as well as for the manufacture of yeast, was also 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 and to disinfect surfaces and tools.
There are drugs with formaldehyde in the following forms:
In personal care products, the E240 preservative 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.
With the help of formaldehyde, gelatin is tanned to produce a film.
Features of containers for storing additives E240
Formaldehyde is most often transported and stored as a solution, not a gas. For these purposes, use glassware, such as bottles, as well as barrels and tanks made of stainless steel. For some metals, formaldehyde causes corrosion, and this fact must be considered when choosing the packaging material for it.
Regulatory requirements for the release of substances from various materials
The international community has settled the issue of standardizing formaldehyde vapor emissions for formaldehyde-containing elements by defining three classes of safety requirements for such emissions: E1, E2, E3. For example, the most strict class of E1 requirements has been established for furniture - 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 emission of toxic fumes should be negligible.
The high content of formaldehyde resins in materials such as chipboard and fiberboard, determines their great strength, but also strong toxicity. Today, furniture manufacturers offer consumers another option for raw materials - MDF or medium density fiberboard. 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 Hygienic standards. They indicate that a single concentration for settlements should not exceed 0.035 mg per 1 cubic meter of air, and the allowable 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 studies of the World Health Organization, the E240 supplement cannot in any way come into contact with food, 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 negatively affects the blood, because of which anemia and leukemia can develop.
The lethal dose of formaldehyde for humans is half a teaspoon of an aqueous solution.
In addition, with constant inhalation of formaldehyde vapor from the air, for example, when smoking, a person may develop symptoms of poisoning that are chronic in nature: nausea, headache, weakness, apathy, blurred vision, tremor of the extremities.
The supplement 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 vapor are very harmful.
The E240 additive, formaldehyde or methanal is still in the international classifications of food additives, although it is strictly forbidden to use it for cooking food in almost all countries of the world. A strong carcinogen, allergen and toxin can severely undermine health, not only through food, but also through the use of furniture and the various chemicals in which it is contained. Formaldehyde resins, although widely used in the chemical industry, are also not safe for humans.