OSB boards: materials, production technology, health hazard testing at home

The health hazards of such an important building material as OSB boards have been discussed for a long time. This is due to production technology, which involves the use of special synthetic resins for polymerization of layers. It is they, according to some researchers, that are the source of toxic substances, which, according to measurements in premises, exceed permissible standards.

OSB production

It should be noted that OSB boards are not only a structural material from which partitions and cladding can be made, but are also often used for the manufacture of furniture. European manufacturers who comply with the E1 environmental protocol claim that finishing interior spaces with their products is completely safe. Let's look at the details of the technological process and the percentage of toxins that enter the room during operation of the stoves.

Production technology

To understand how OSB can affect health , you need to know production technology. Particular attention should be paid to the components of the future material. The use of one low-quality component spoils the product as a whole.

Production stages:

Receipt of raw materials and their processing. The main component of OSB boards is waste from the wood processing industry - non-business wood that was rejected. Wood waste is soaked at a certain temperature and cleaned.
Slicing. At this stage, wood chips are obtained from waste by machine.
Drying. The resulting raw materials are dried, which takes some time. If the chips dry out quickly, they may cause damage.
Mixing. To bind wood chips, a composition of glue and resins is added to it, and other binding components may also be present in different volumes.
Laying. Using molding machines, the mixed component is laid in several layers. Each subsequent layer is laid perpendicular to the previous one.
Pressing. The resulting mass is compressed by a press and cut to a given size.

The main component of OSB boards is wood chips. This is an environmentally friendly component. The adhesive composition can be dangerous because it often contains formaldehyde resins.

Natural wood can also emit acceptable levels of formaldehyde. Therefore, talking about the safety of fresh wood is a controversial issue. But since wood chips for OSB have been processed, they are considered safe.

Manufacturers who value their customers and reputation claim the safety of the material. According to them, high quality OSB is achieved through endurance, and not through the power of the press. The press only gives the shape, and the chip material is bonded with resins over time. Since the binding period is long, formaldehyde has time to erode from the structure of the boards. The concentration of the substance drops, and it does not have a negative effect on human health.

What are melamine, urea and phenol formaldehyde?

The principle of “working” of the synthetic resins included in OSB is the high adhesive properties of the glue and its subsequent irreversible polymerization (transition from a fluid to a solid state). Modern polymers have a structure that is indestructible by conventional methods; this quality is called cohesive strength. With the “correct” OSB adhesive composition, the board does not change its characteristics when exposed to temperature or the addition of solvents. It is this quality that makes it possible to achieve water resistance of the polymer adhesive and the resulting product.

When individual components, for example, phenol and formaldehyde, interact, low-molecular structures are formed - resoles, which during polymerization change their structure from linear (branched) to spatial, reminiscent of a crystal lattice. The process of thickening the glue includes a gradual transition of resols into resitols with a rare spatial lattice, then into resits having a spatial lattice with frequent molecular connections (polymers).

Thus, phenols, formaldehyde, urea, melamine in the resin composition are not only in a state bound by a chemical compound, but also have a spatial structure. The release of pure substances from the spatial lattice is difficult, and when the formulation is improved, it is minimized as much as possible. In their free state, the substances that make up synthetic resin also have limited toxicity. Taken together, it cannot even be theoretically assumed that OSB boards are harmful to health.

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Melamine

Melamine
Melamine is widely used in the production of resins and tannins, the carcinogenic properties of melamine-formaldehyde resins are minimal, the substance is approved for the manufacture of food utensils. Some toxicity is observed in pure melamine; sponges are produced on its basis for household use; they are not used for washing dishes. The toxicity of melamine is low, but the use of products containing it is not recommended.

Urea

Urea is a substance widely used in agriculture, cosmetics production, and industry. Urea is found in the human body and is involved in cellular metabolism. When used in the production of OSB boards, it imparts increased adhesive properties to the layers, facilitating the establishment of strong connections in multilayer structures.

Phenol

Phenol is a substance that is highly toxic to people and the environment. At the same time, the amino acid tyrosine, which is essential for humans, is also a derivative of phenol. The toxicity of this substance decreases with the formation of stable chemical compounds. Used in the production of polycarbonate, epoxy paints and resins. During hydrogenation it becomes nylon and nylon. It is used to disinfect animals and is included in cosmetics and medicines as a preservative. In case of poisoning in significant quantities, it is absorbed through the skin and causes paralysis of the respiratory center.

Formaldehyde

Formaldehyde is part of many solvents, including technical formalin. It is used in agriculture for fumigation of grain before winter storage and transportation. Used in the food and cosmetics industries as a preservative, registered under food code E240. Safe in an amount of 0.5%, used in anti-sweating products. In an amount of 0.05% it is freely used in the food and cosmetics industries for disinfection of compositions. It exhibits toxicity only upon contact with human skin in excess quantities.

From the given characteristics it becomes clear that the toxic effect on the human body of the resins that make up OSB is extremely small. This is confirmed by the hygienic certificates of the Russian Federation for products, which large factories receive for the purpose of supplying to the market of the Russian Federation. OSB boards from European and American manufacturers have passed the so-called “children's” certification.

However, the assumption that OSB is completely safe for adults and children does not apply to products with dubious origins and fake quality certificates, which is typical for many Asian manufacturers. If there are doubts about the quality of the OSB board and the manufacturer’s compliance with environmental safety standards, it is better to use such products for exterior finishing.

Application: pros and cons

Manufacturers widely advertised their brainchild. OSB is gaining great popularity , especially in the West, where time is valued: the use of boards allows for faster construction of structures.

Material properties:

Strength. The material can withstand heavy loads and also has high bending, tearing and compressive strength. Plates can be subjected to pressure of several hundred kilograms per square meter.
Low weight. Binding elements based on resin and glue are lighter than wood - this allows for some weight reduction.
Slight deformation. The slabs can be used as cladding.
Noise and thermal insulation. OSB sheets conduct heat poorly. When installed correctly, they suppress noise up to 8 dB.

OSB is also used for the production of SIP panels:

The material is easy to process and easy to install.
Resistant to mechanical stress.
Relatively easily tolerates changes in temperature and humidity.

These properties, coupled with the low cost of the material and the relative ease of production, lead to widespread use in construction. Recently, the material has become widespread not only in industrial construction, but also for housing.

Negative aspects of the material:

Direct contact with water causes the material to swell. Material from some manufacturers can increase in size by up to 25%.
It is difficult to carry out communications under the mounted sheets, as well as to change the insulation.
The material is fire hazardous due to its high resin content. Treatment with fire retardants slightly reduces this factor.
Susceptible to fungi and mold, rodents and beetles can also damage the slabs.
It costs more than gypsum board and chipboard sheets.

This is a small thing compared to the fact that, according to marketing research, potential buyers consider the material harmful to health and do not want to use it in construction.

What harmful substances are contained in OSB and how do they get there?

These boards are made by heat pressing large-sized shavings (small chips) of coniferous wood, laid in layers and oriented layer-by-layer. The multidirectional orientation of chips in different layers provides increased strength and rigidity of the material, due to which OSB is widely used in construction (cladding house frames, laying subfloors, formwork production, production of SIP panels), in furniture production, in the manufacture of containers, etc. .

Special adhesives are used as a wood pulp binder in the production of OSB boards, the main components of which are various synthetic resins - melamine-formaldehyde, urea-formaldehyde or phenol-formaldehyde. From the name of all these resins, it is easy to guess that one of the reagents in their synthesis is formaldehyde. This means that each resin, depending on its quality, contains one or another amount of unreacted aldehyde.

Free formaldehyde can also be released as a result of partial depolymerization of the resin, which occurs under the influence of high (up to 200°C) temperatures at which the process of pressing glue-impregnated chips is carried out. A significant part of this toxic substance will evaporate already in the production shops, but the residues will “ooze” out of the finished slab for a long time: the level of formaldehyde emission is halved within about six months from the date of production.

The release of formaldehyde also occurs during the operation of OSB boards: the slow destruction of formaldehyde resins (and primarily less persistent urea-formaldehyde resins) can be a consequence of exposure to various unfavorable environmental factors - moisture, elevated temperature, ultraviolet rays.

To be fair, it should be noted that the source of formaldehyde can be not only synthetic resin, but also wood itself, traditionally considered the standard of environmental friendliness. Formaldehyde emissions from freshly harvested wood can reach 0.2 mg/m3. With proper drying of lumber, this indicator decreases and becomes significantly lower than the background created by low-quality synthetic glue.

Harmfulness of OSB

The production of slabs was first established in Canada more than 30 years ago. The technology then spread to North America and Europe. In the post-Soviet space, technological solutions were drawn from Western countries. For the most part, production is borrowed, but there are organizations that work on cheaper equipment. As a result, some stages fall out of the production process, which are removed or replaced with cheap ones.

Classification of OSB boards

Manufacturers mark OSB boards according to the European standard. Their classification is based on the formaldehyde content in the resin. Based on this, we can talk about the safety of the material.

Current marking:

E 0.5. The permissible rate is no more than 4 mg per 100 g of dry slab. There should not be more than 0.08 mg/m3 present in the air.
E1. No more than 8 mg. Concentration in the air - no more than 0.124 mg/m3.
E2. Resin concentration up to 20 mg. There should not be more than 0.5 mg/m3 in the air.

Material of any category contains formaldehyde. Manufacturers abroad are strictly controlled by the state, so environmental standards are observed.

The degree of environmental friendliness of the material

It would seem that if the use of OSB boards in construction is not prohibited in Western countries, they do not affect human health. In the domestic market, not everything is clear due to the following reasons:

Manufacturers abroad strictly comply with environmental standards, but in the former USSR countries they often use cheap Asian materials containing harmful substances in quantities dangerous to humans. However, slabs made from such materials are popular due to their low cost.
In the domestic market, small producers sin by failing to comply with production technology. You can reduce the amount of harmful substances as follows:
Production costs increase, but the harmful formaldehyde is sealed inside the slab.

The material by nature contains pores, whether it is polymers, paint or wood. Research into the direction of formaldehyde penetration through wood has not been carried out. This should be taken into account when choosing OSB.

How to protect yourself from toxic fumes

Even the high safety class of the panels does not exclude the release of toxic gases. If you nevertheless decide to use sheets in construction, you can reduce the risk of harm to OSB in a residential area by following several rules:

For the production of furniture and interior decoration of living rooms and premises, it is better not to use OSB, but to give preference to chipboard or plywood.
If you still use oriented strand boards indoors, they should be insulated with finishing: tiles, wallpaper or paint.
Excessively high temperatures or high humidity should be avoided in the room. Under these conditions, the release of formaldehyde accelerates.
A ventilation system and ventilation will help reduce the risk of intoxication.

OSB is still harmful to health, since it invariably contains synthetic resins. However, with high-quality production technology, a high safety class and proper operation, OSB panels will not cause harm to health.

Be vigilant when purchasing

Financial affairs have not been going well for domestic consumers lately. As a result, people try to purchase material at a low cost, but a low price may indicate poor quality of the material. It will contain formaldehyde in a significant amount, which clearly exceeds the permissible standards.

Therefore, when purchasing glued material, you should pay attention to the following characteristics:

Presence of a pungent odor. Toxic glue gives off a sharp, unpleasant odor that goes into the nose.
Availability of a certificate. Each seller must receive this document from the manufacturer. Sometimes the procedure may be voluntary, but a conscientious manufacturer will still provide documentation.
Product labeling. Each sheet must be marked. For OSB boards, the technical characteristics are as follows: the indicator of harmfulness to humans is indicated at the end.
Price. The low price of the material, as well as sale on a spontaneous market from an incomprehensible seller, will not provide any guarantees regarding quality or safety.

If something is suspicious, it is better not to purchase such material. By paying more for a quality product, the consumer protects his health. This is especially true for young children.

Actions after purchase

Lucky is the one who read the article before going to the store. These readers can think about their decision, weigh the pros and cons.

The release of formaldehyde does not continue indefinitely - eventually its concentration in the material drops to a safe level, even in material that was manufactured in violation of environmental standards. But to do this you will need to do the following:

Ventilate the material before installation until the characteristic pungent odor disappears completely. The same must be done with the room if the installation has already been completed. Airing will take a little longer.
The surface of the material must not be wetted with water. Because of this, formaldehyde is released more strongly - in proportion to the increase in humidity.
The room temperature should not exceed 30 degrees.
If clothes smell toxic, they should be washed thoroughly several times.

If you don't mind the money, you can buy an air purifier with a photocatalytic filter, or at least rent it for a week or two. Such a device is capable of neutralizing a toxic substance from the air in a short time.

To know for sure whether the installed OSB board is harmful to health, there is a proven and reliable method. You will need an aquarium with fish. It must be installed in a room with OSB material. If the concentration of formaldehyde in the air exceeds the permissible limit, then the fish will not survive.

Dieffenbachia is an indoor flower that can absorb toxic substances from the air. Its presence will help reduce the amount of formaldehyde.

Some rules for greater safety

The first time (about six to seven months) after installation, the most intense release of harmful fumes occurs. If you regularly ventilate the room, the negative impact on the body will soon begin to subside. But for greater safety, additional processing of the slabs is carried out.

If the work takes place in a children's room, then compositions with detoxifying properties are chosen as a primer. For common areas, simple water-dispersed paints, varnishes, wax, and penetrating primer are suitable.

Particular attention is paid to the ends. It is through them that the main amount of harmful substances is released. It is enough to saturate them with varnish or primer.

Priming is one of the safety measures that allows you to reduce the amount of harmful substances released

On a note! Simple surface covering is the best guarantee of protection against the release of harmful substances.

It should be taken into account that the rate of release of toxic elements is affected by temperature. The higher the indicator, the more formaldehyde in the air. The norm is considered to be 30 °C.

In general, there are two main ways that allow, without making excessive efforts, to rid the room of chemical components and saturate it with oxygen. Namely, frequent ventilation and the presence of indoor flowers.

OSB is not recommended for use in rooms where temperatures exceed 30 °C

Any modern building or finishing material that is made using chemical components can emit harmful substances. But manufacturers are constantly trying to keep these figures to a minimum.

Effects of formaldehyde on the body

Few consumers question the impact of formaldehyde on human health. However, the impact of poisonous gas on human health is serious. Phenol contained in the air has the following negative effects:

The carcinogen poisons all human organs.
Causes irritation on mucous membranes.
Causes disruptions in the functioning of the cardiovascular system.
Irritates the nervous system.

If, after moving to a new premises, residents began to complain of nausea, constant dizziness, and sluggish health, then it is worth checking the materials from which the interior of the rooms is made. Most likely, the reason is low-quality OSB boards.

The material should be treated with caution, especially cheap ones: in any case, it contains formaldehyde, which negatively affects health. The only question is the concentration - is it safe? However, by carefully selecting slabs, following advice on safe selection, you can purchase safe and high-quality material for construction that does not contain dangerous concentrations of formaldehyde.

It is not without reason that such material has become widespread in Western Europe and North America due to its relatively low cost. However, it should be remembered that production control there is strict, and the domestic consumer has no choice but to be strict about the choice in the store.

Those who have already purchased this material should not be upset. The effects of formaldehyde can be eliminated by normal ventilation. This will take considerable time, but will save your health.

Identification of phenol sources

Only specialists can conduct a full examination of the air, as well as interior items and other sources that may contain hazardous substances. Their job is to perform a chemical analysis of the air and the impurities in it.

It is worth mentioning right away that it is not always the OSB board that is the culprit of all troubles. Elements containing phenol can be found even in objects that seem quite safe at first glance. This could be furniture, textiles (carpets made from non-natural materials), decorative elements and even children's toys.

In order to reduce the cost of their products, manufacturers, alas, do not disdain using any means to achieve their goals, and therefore very often cheap things are fraught with danger - this is a harsh reality.

Useful video

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Material cost

The final cost of smallpox depends on the strength class, flammability and other characteristics.

On average, a sheet measuring 1.25 * 2.5 m with a thickness of 9 mm costs around 600 rubles , this is the price at the time of publication of the article and it may change in the future.

When compared with plywood of similar sizes, plywood is 2 times more expensive. Chipboard is a little cheaper.