9th International Exhibition "Wooden house building / HOLZHAUS" took place from 13 to 16 November at Crocus Expo IEC. And if at this exhibition exhibits promoting expanded polystyrene have practically disappeared - as effective for use insulator for low-rise wooden construction, then the exhibits in which polyurethane foam there was plenty of it. To the questions that arose during the conference held on the use of these materials in construction, we answer this article.
V last years foamed polymer thermal insulation materials... Indeed, from the point of view of thermal physics, these are the most efficient heat insulators. But when it comes about housing, about such a product construction production, with which a person will have to communicate daily for many hours for decades - some thermophysical properties are not enough. The main thing here is chemical safety and durability.
The main reason for the chemical hazard lies in the nature of the polymeric materials. The fact is that:
1. The polymerization process does not go to the end, but only 97-98%;
2. The polymerization process is reversible, therefore polymers constantly decompose (destruction process) under the influence of light, oxygen, ozone, water, mechanical and ionizing effects, and especially under the influence of warmth. The combination of these factors leads to a relatively short service life of polymers - on average 15-20 years, after which they turn into powder.
Polymers are dispersed organic compounds with a very high surface of contact with atmospheric oxygen with an oxidation reaction. And the products of their oxidation, even at room temperature, negatively affect environment... Moreover, as the temperature rises, the oxidation rate increases.
All polymer insulation materials are FIRE HAZARDOUS and the main damaging factor in fires is the volatile combustion products of foamed polymers. Only 18% of people die from burns, the rest from POISONING.
According to the fire hazard classification, all FOAMED POLYMERS belong to the class "G", that is, "FLAMMABLE MATERIALS".
Problem fire hazard Styrofoam is usually viewed from two sides:
- the danger of the actual combustion of polymers (pyrolysis),
- the danger of products of thermal decomposition and oxidation of the material (destruction).
Toxicological hazard of expanded polystyrene
At first glance, the safest among organic polymers should be POLYSTYRENE, because in the process of its polymerization, foaming and subsequent degassing, the toxicity of STYROL should be eliminated. However, POLYSTYRENE (PS), from which POLYSTYRENE PEN is made, belongs to equilibrium polymers, i.e. is in thermodynamic equilibrium with its highly toxic monomer - STYROL (C):
PS n = PS n-1 + C.
Therefore, this polymer is subject to the depolymerization process with the release of the monomer - STYROL.
STYRENE is a highly toxic substance. The heart suffers from micro doses of styrene, special problems arise in women (styrene is an embryogenic poison that causes the deformity of the embryo in the womb). Styrene has a strong effect on the liver, causing toxic hepatitis, among other things. Styrene vapors irritate mucous membranes. It has the strictest tolerance of all toxic substances (the MPCsut of STYROL is 1500 times less than, for example, carbon monoxide) that can be released from building materials (see table 1)
Such a low value of MPC for styrene and, accordingly, multiple excess of its MPC standards in a room is caused by the special properties of styrene. This substance belongs to condensed aromatic compounds that have one or more benzene nuclei in their molecule, and, like similar substances (benzene, benzopyrene), has increased communicative properties: it accumulates in the liver and is not excreted. Substances of this group are classified as especially hazardous. For example, benzopyrene is an active carcinogen with an MPC of 0.000001 mg / m3.
There are two concepts for assessing the impact of harmful substances on the human body:
Threshold. The threshold concept states that lowering concentrations harmful substances it is necessary up to a certain level (threshold), determined by the value of the maximum permissible concentration (MPC). The conclusion follows from this position: low concentrations of harmful substances (below the MPC level) are harmless. In our country (as well as in other countries the former USSR), it is the threshold concept that has been adopted. Linear. The linear concept assumes that the harmful effect on a person is proportional (linear) dependent on the total amount of absorbed substance. Hence the conclusion: low concentrations with prolonged consumption are harmful. This concept is adhered to by the USA, Germany, Canada, Japan and some other countries. But when considering the toxic danger of exposure to harmful substances on a person, it is necessary to take into account the degree of their COMMULATIVITY, i.e. the ability of a substance to accumulate in the human body over time.
STYRENE among the substances contained in building materials, has the highest degree of commutability - 0.7 (see table 1). If we imagine that polystyrene with a thickness of 160 mm (in a three-layer panel) will last 20 years, then during this period, each square. meter outer wall will release 3 mg / h of styrene. When 10% of this amount enters the room and air is supplied in an amount of 30 m3 / m2 h, the styrene concentration will be 0.0075 mg / m3. With a temporary stay in such a room and orientation to the daily MPC = 0.002 mg / m3, the excess of MPC for styrene will be 3.75 times.
Therefore, for a dwelling with a residence time of 25 years, the MPC for styrene should be reduced by 594 times and amount to 0.0000034 mg / m3 (see table).
Table 1. Reduction of the MPC value of harmful substances when taking into account their degree of commutativeness.
| Substance | MPC, mg / m3 | Degree of commutativeness | Decrease in MPC | The recalculated MPC, mg / m3 | |
| one-time | daily | ||||
| Carbon monoxide (carbon dioxide) | 5 | 3 | 0,1195 | 3 | 1,0000000 |
| Methanol | 1 | 0,5 | |||
| Carbon monoxide ( carbon monoxide) | 20 | 0,02 | |||
| Nitrogen dioxide | 0,085 | 0,04 | 0,176 | 5 | 0,0080000 |
| Phenol | 0,01 | 0,003 | 0,2815 | 13 | 0,0002308 |
| Ammonia | 0,2 | 0,04 | 0,376 | 31 | 0,0012903 |
| Nitric oxide | 0,4 | 0,06 | 0,444 | 57 | 0,0010526 |
| Formaldehyde | 0,035 | 0,003 | 0,575 | 188 | 0,0000160 |
| Benzene | 1,5 | 0,1 | 0,633 | 322 | 0,0003106 |
| Styrene | 0,04 | 0,002 | 0,7005 | 594 | 0,0000034 |
Output: STYRENE requires a decrease in MPC when used in housing construction by about 600 times to the level of 0.0000034 mg / m3, which is equivalent to a complete ban on the use of POLYSTYRENE in housing construction.
Flammability of expanded polystyrene
Due to this property, expanded polystyrene in the form of pre-foamed granules was used as a component for napalm bombs to burn enemy armored vehicles. Expanded polystyrene melts and its melt burns with a temperature above 1100 ° C. It is the only polymer that burns at such a high temperature. Therefore, when a building ignites, in which there is a significant content of expanded polystyrene, everything burns, even metal structures.
In turn, when polystyrene burns, its thermal destruction occurs, in which a significant amount of substances hazardous to humans is released. Therefore, back in the Soviet Union, with a unified system of sanitary and chemical control over the use of polymeric materials, the USSR Ministry of Healthcare prohibited the use of expanded polystyrene in construction.
In connection with the above, in western Europe 20 years ago, expanded polystyrene was completely removed from residential buildings. The main peaceful use of expanded polystyrene in northern Europe and Canada is for insulating road and railway tracks... To give the road durability, plates of this material are added to the body of its "puff cake". Moreover, not foamed is used, but extruded polystyrene foam(technology developed by BASF, Germany) with a tough and durable shell. This makes it possible for the expanded polystyrene not to be saturated with moisture, to keep heat insulating ability and prevent freezing of the roadway - which is the main reason for its rapid destruction. The use of expanded polystyrene in greenhouses is also effective, especially in the northern regions. Studies have shown that toxic STYRENE is not released into a humid environment, but remains in expanded polystyrene without causing any harm. In addition, under a layer of sand, gravel or soil, there is no question of the fire hazard of styrene foam. That's where this stuff comes in.
Fire hazard of polyurethane foams ("Isolation of a complete set of chemical warfare agents")
Unlike expanded polystyrene, rigid polyurethane foam is a toxic inert polymer with a neutral odor. For this reason, it is widely used for food storage refrigerators. Polyurethane foam does not create toxic emissions that can cause human disease or death.
But as a result of the combustion of polyurethane foams and polyisocyanurate foams, a mixture of low-molecular thermal decomposition products and their combustion products is always formed. The composition of the mixture depends on temperature and oxygen availability.
The process of dissociation of polyurethane foam into the initial components - polyisocyanate and polyol - begins after heating the material to 170-200 ° C.
With prolonged exposure to high temperatures above 250 ° C, the gradual decomposition of most thermosetting plastics, as well as rigid polyurethane foams, occurs.
When the isocyanate component is heated above 300 ° C, it decomposes with the formation of volatile polyureas (yellow smoke) in the case of flexible polyurethane foams or the formation of non-volatile polycarbodimmides and polyureas in the case of rigid polyurethane foams and polyisocyanurate foams. Thermal decomposition of the polyisocyanate and the polyol takes place.
At temperatures exceeding 300 ° C, the destruction of polyisocyanurate foam begins, containing, in contrast to polyurethane foam, a more stable isocyanurate cycle. The temperature at which it forms enough combustible decomposition products that can ignite from flames, sparks or combustible surfaces, for rigid polyurethane foams from 320 ° C.
For rigid polyurethane foams based on special grades of polyisocyanate, the decomposition temperature with the release of combustible gases is in the range from 370 ° C to 420 ° C. In addition, during the decomposition various polyurethane foams when heated to 450 ° C, the following compounds were determined: carbon dioxide (carbon dioxide), butanediene, tetrahydrofuran, dihydrofuran, butanedione, water, hydrocyanic (cyanic) acid and carbon monoxide (carbon monoxide).
Carbon monoxide (carbon monoxide, carbon monoxide, CO).
Carbon monoxide is the main toxic component of the combustion products of polyurethane foams and polyisocyanurate foams at all stages of a fire, both at low and high temperatures.
The natural level of CO in the air is 0.01 - 0.9 mg / m3, and on highways in Russia the average concentration of CO is 6-57 mg / m3, exceeding the poisoning threshold. Carbon monoxide (carbon monoxide) is toxic, it has the ability to combine with blood hemoglobin 200-300 times faster than oxygen. The blood becomes unable to carry enough oxygen from the lungs to the tissues, and rapid and severe poisoning occurs.
At a CO content of 0.08% in the inhaled air, a person feels a headache, nausea, weakness and suffocation. At 1% concentration of carbon monoxide in the room, after 1-2 minutes, it has a lethal effect. With an increase in CO concentration to 0.32%, paralysis and loss of consciousness occurs (death occurs after 30 minutes). At a concentration above 1.2%, consciousness is lost after 2-3 breaths, the person dies in less than 3 minutes.
Hydrocyanic acid (cyanous acid, hydrogen cyanide, formic acid nitrile, HCN).
In the combustion products of polyurethane foams and polyisocyanurate foams, the presence of hydrocyanic acid is observed, the release of which is 10 times less than the carbon monoxide content.
Hydrocyanic acid (hydrogen cyanide, hydrocyanic acid) (HCN) is a colorless transparent liquid with a boiling point of + 25.7 ° C. Due to its low boiling point, hydrocyanic acid is very volatile, especially in a fire. It is a very strong general toxic poison. It has a peculiar intoxicating smell, reminiscent of the smell of bitter almonds.
The average daily maximum permissible concentration (MPC) of hydrocyanic acid in the air of populated areas is 0.01 mg / m3; in workrooms industrial enterprise- 0.3 mg / m3. An acid concentration below 50.0 mg / m3 is unsafe if inhaled for many hours and leads to poisoning. At 80 mg / m3, poisoning occurs regardless of exposure. If 15 minutes are in an atmosphere containing 100 mg / m3, then this will lead to severe injuries, and more than 15 minutes - to death. Exposure to a concentration of 200 mg / m3 for 10 minutes and 300 mg / m3 for 5 minutes is also fatal. Both gaseous and liquid hydrocyanic acid are absorbed through the skin. Therefore, if you stay in an atmosphere with a high concentration of acid for a long time without skin protection, even if you wear a gas mask, there will be signs of poisoning as a result of resorption.
Among the products of thermal decomposition (destruction) of polyurethane foams containing polyethylene glycols are found: methane, ethane, propane, butane, ethylene oxide, formaldehyde, acetaldehyde, ethylene glycol, water and carbon monoxide. In addition to the listed substances, propylene, isobutylene, trichlorofluoromethane, acrolein, propanal, methylene chloride and traces of other substances that do not contain nitrogen atoms were also found in the composition of the decomposition products of polyols.
If there is no external source of ignition, then thermal decomposition products ignite only at temperatures from 450 ° C to 550 ° C. When heated above 600 ° C, the formed polyureas and polycarbodimmides decompose with the release of a large number of low molecular weight volatile compounds such as benzene, toluene, benzonitrile, toluene nitrile. It was also shown that the aromatic ring of the listed nitrogen-containing compounds splits according to the law of chance with the formation of acrylonitrile, a large number of unsaturated compounds.
Under the conditions of a real fire, the products of thermal destruction actively burn with the formation of water, carbon dioxide and carbon monoxide as well as nitrogen oxides.
When choosing such a heater, you must remember that: polyurethane foams and polyisocyanurate foams, in comparison with other organic materials, emit a significant amount of toxic products when exposed to high temperatures.
But, unfortunately, in our country there are many organizations that "produce" components of polyurethane foams in an artisanal way. Therefore, after some time is running decomposition of the material, thermophysical characteristics are an order of magnitude worse than recommended, the concept of "durability" in this case is not applicable at all. Typically, no fire retardant is added to this surrogate. Therefore, such "polyurethane foam" burns well with the release of various chemical warfare agents.
There is no entrance control in construction. Thermal insulation works building structures mostly lie on the conscience of the invited workers, most often guest workers.
In conclusion, we present data on the concentration of volatile toxic substances released during a fire and their impact.
table 2
| Title and chemical formula | Impact description | Concentration | Symptoms |
| Carbon monoxide, carbon monoxide, CO | As a result of combining with blood hemoglobin, an inactive complex is formed - carboxyhemoglobin, which causes a violation of oxygen delivery to the tissues of the body. It is released during combustion of polymeric materials. The release is facilitated by slow combustion and a lack of oxygen. | 0.2-1% vol. | Death of a person for the period from 3 to 60 minutes. |
| Carbon dioxide, carbon dioxide, CO2 | It causes an increase in breathing and an increase in pulmonary ventilation, has a vasodilating effect, causes a shift in the pH of the blood, and also causes an increase in the level of adrenaline. | 12% vol. | Loss of consciousness, death within a few minutes. |
| 20% vol. | Immediate loss of consciousness and death. | ||
| Hydrogen chloride, hydrogen chloride, HCl | Reduces the possibility of orientation of a person: in contact with a wet eyeball, it turns into hydrochloric acid... Causes respiratory spasms, inflammatory edema and, as a result, respiratory failure. Formed by combustion of chlorine-containing polymers, especially PVC. | 2000-3000 mg / m3 | Lethal concentration on action for several minutes. |
| Hydrogen cyanide, (hydrogen cyanide, hydrocyanic acid), HCN | It causes a violation of tissue respiration due to the suppression of the activity of iron-containing enzymes responsible for the use of oxygen in oxidative processes. Causes paralysis of the nerve centers. It is released during combustion of nitrogen-containing materials (wool, polyacrylonitrile, polyurethane foam, laminated plastics, polyamides, etc.) | 240-360 mg / m3 | Death within 5-10 minutes |
| 420-500 mg / m3 | A quick death | ||
| Hydrogen fluoride, (hydrogen fluoride, HF) | Causes the formation of ulcers on the mucous membranes of the eyes and respiratory tract, nosebleeds, spasm of the larynx and bronchi, damage to the central nervous system, liver. There is cardiovascular failure. It is released during combustion of fluorinated polymeric materials. | 45-135 mg / m3 | Dangerous to life after a few minutes of exposure |
| Nitrogen dioxide, NO2 | When it enters the bloodstream, nitrites and nitrates are formed, which convert oxyhemoglobin to methemoglobin, which causes oxygen deficiency in the body due to damage to the respiratory tract. It is assumed that in case of fires in residential buildings there are no conditions necessary for intensive combustion. However, there is a known case of mass death of people in a clinical hospital due to the burning of X-ray film. | 510-760 mg / m3 | When inhaled within 5 minutes, bronchopneumonia develops. |
| 950 mg / m3 | Pulmonary edema | ||
| Ammonia, NH3 | It has a strong irritating and cauterizing effect on mucous membranes. Causes profuse lacrimation and pain in the eyes, choking, severe coughing fits, dizziness, vomiting, swelling of the vocal cords and lungs. Formed by burning wool, silk, polyacrylonitrile, polyamide and polyurethane. | 375 mg / m3 | Allowable for 10 minutes |
| 1400 mg / m3 | Lethal concentration | ||
| Acrolein (acrylic aldehyde, CH2 = CH-CHO) | Light dizziness, flushing of the head, nausea, vomiting, slow pulse, loss of consciousness, pulmonary edema. Severe dizziness and confusion are sometimes noted. Sources of vapor emission - polyethylene, polypropylene, wood, paper, oil products. | 13 mg / m3 | Transportable no more than 1 min |
| 75-350 mg / m3 | Lethal concentration | ||
| Sulfur dioxide (sulfur dioxide, sulfur dioxide, SO2) | On a wet surface, mucous membranes are successively converted into sulfurous and sulfuric acid. Causes cough, nosebleeds, bronchospasm, disrupts metabolic processes, promotes the formation of methemoglobin in the blood, acts on the hematopoietic organs. It is released when burning wool, felt, rubber, etc. | 250-500 mg / m3 | Dangerous concentration |
| 1500-2000 mg / m3 | Lethal concentration when exposed for several minutes. | ||
| Hydrogen sulfide. H2S | Irritating to eyes and respiratory tract. The appearance of seizures, loss of consciousness. Formed when burning sulfur-containing materials. | 700 mg / m3 | Severe poisoning |
| 1000 mg / m3 | Death within minutes | ||
| Smoke, steam-gas-aerosol complex | It contains solid particles of soot, liquid particles of resin, moisture, condensation aerosols that carry out a transport function for toxic substances during breathing. In addition, smoke particles adsorb oxygen on their surface, reducing its content in the gas phase. Large particles (> 2.5 μm) are deposited in the upper respiratory tract, causing mechanical and chemical irritation of the mucous membrane. Small particles penetrate the bronchioles and alveoli. If taken in large numbers, airway obstruction is possible. |
With the simultaneous entry of combustion products into the human body, a complex effect of joint exposure is observed, and an increase in temperature during a fire increases the body's sensitivity to the toxic effects of harmful substances.
Is PPU environmentally friendly? Is PPU harmful?
First, let's figure out what is polyurethane foam?
Polyurethane foam Is a plastic obtained in the course of thermosetting chemical reaction... The structure of this material is similar to that of a regular soap suds, it consists of cells isolated from each other, inside of which gas is contained, only cells with the same size, unlike ordinary foam. Solid polymer makes up only 3-5% of the total volume of polyurethane foam, and the remaining 95-97% is gas, which is a heat insulator.
The fact that polyurethane foam has a full set of environmental indicators is confirmed by both a number of hygienic certificates and realities. The chemical resistance of this material is indicative, which determines its long service life, and indirectly confirms its environmental friendliness. Both polyurethane foam and polyurethane do not decompose, do not interact with anything, and therefore are completely inert. In addition, today the use of highly volatile ether fractions in the creation of these materials has been completely ruled out.
It should be noted that these materials do not contain asbestos, formaldehyde and other chemicals. The spraying of polyurethane foam was accompanied by checks that did not reveal any harmful substances in the atmosphere of the room. The biological neutrality of polyurethane foam, which turns out to be resistant to mold and bacteria, to decay processes, is also indicative. This material does not cause any allergies.
When using polyurethane foam, pillows and mattresses are manufactured, it is used to create sofas and transport seats. It is also used as thermal insulation in boilers or refrigerators, as well as in other equipment that may come into contact with food... We can use PU foam even in beekeeping, where it is used to create hives modern design... And it is also used in septic tanks, where it is necessary to create surfaces for colonization with bacteria - practice shows that in such conditions even a stone has a shorter period of destruction than polyurethane foam.
Polyurethane foam is widely used in medicine for the manufacture of various devices, and sometimes it comes into contact not only with drugs intended for ingestion, but also with human mucous membranes - as an example, we can consider equipment for taking an impression in dentistry, prosthetics. As a conclusion, it can be emphasized that the volume of consumption of such material by modern mankind really turns out to be very high, and a person can almost constantly contact with it.
Continuing the consideration of the list of advantages that this material possesses, it should be noted that its use as a heater for houses and other buildings becomes advisable also because rodents show complete indifference to it. Rats and mice do not try to gnaw this material, and their digestive system is unable to digest it due to the above-mentioned reason for its chemical stability.
Also, the fact that PPU modern sample although they are capable of burning, they themselves do not spread fire, being self-extinguishing. There are different degrees of flammability of such materials - G1, G2, G3, and the lower the digital indicator, the slower they burn. G3 is still used most often, because its cost is lower. A low burning rate and self-extinguishing are provided due to the introduction of fire retardants into the composition of such a material, which remain in the closed capsules of the material forever - the indicator will not decrease over time.
Speaking of vapor barrier and decay
Closed-cell polyurethane foam of decent quality does not require any vapor barrier - especially since the polyurethane foam modern type have more than 92 percent of closed cells, and therefore a vapor barrier is definitely not required, and such insulation will not absorb moisture.
That is, closed cells or a good vapor barrier are absolutely necessary to ensure the normal functioning of heaters - especially if we talk about climates with serious negative temperatures. But even at positive temperatures, when there is no risk of destruction of the insulation due to freezing of moisture crystals in it, closed-cell options are most preferable, since the thermal conductivity of such a material will be stable, while an open-celled material will significantly increase the thermal conductivity.
Porous materials such as cellulose, being in constant moisture, are prone to rotting, mold formation, and even if initially it is not there for a year or two thanks to the use of special chemistry then it will show itself later. So the benefits of using PPU are fully obvious.
In cars, seats, a front torpedo, various door linings, etc. are made of polyurethane foam. They even make bee hives from polyurethane foam. All these things undergo strict quality control for the safety of human use. Industrial polyurethane foam is the same mattress, but very hard and can be stuck on a wall or even a ceiling. In the section of our website called you will find confirmation that polyurethane foam from various manufacturers after application and polymerization does not emit harmful substances, and there are simply no terrible formaldehydes and other harmful resins in the polyurethane foam.
The properties of polyurethane foam allow it to be used in the construction of children's and medical institutions, in the food industry, where the requirements for air purity and fire safety are especially stringent.
Polyurethane foam, otherwise - foam mattress, is still quite common. At first glance, it seems that the foam is dense enough and is quite suitable for sleeping on it. However, experts are of the opposite opinion and do not recommend mattresses with polyurethane foam filling for sleeping.
Polyurethane foam, foam rubber or PP, what is it? - let's figure it out. The material was invented in 1937 by a group of German scientists. The rapid growth in consumption of polyurethane foam among the population began in the 60s of the last century.
It is possible to speak about the benefits or harms of PPU only by studying its properties. The material with a foam structure is of artificial origin, which already initially speaks not in its favor. The chemical components that make up its composition do not like moisture, do not like open sunlight - under their influence, the foam rubber is destroyed.
O positive properties PPU say a lot:
- not flammable;
- does not lose its shape (it quickly restores under mechanical action);
- It has high level vapor and water permeability, due to which it is used as a moisture and heat insulating material.
In addition, foam rubber is very cheap, so it is often used as a filler for mattresses. By itself, the foam rubber is very light due to its soft, porous structure; it can be easily bent, twisted to transport.
However, it is too early to fall into euphoria, because PUF contains active chemical components, among which the most dangerous is phenol. In addition, it contains resins, catalysts, and solvents. During combustion (and foam rubber burns in the presence of a direct fire source) toxic components - formaldehydes - are released into the air.
The most dangerous component of polyurethane foam is phenol. Dangerous fumes can last for years, and fumes from new material are more dangerous. Phenol has a destructive effect on critical systems human body: cardiovascular, nervous, respiratory. That is why it is worth thinking 100 times before giving your child a toy stuffed with foam rubber or placing him on a foam mattress.
Phenol vapors can cause serious health problems:
- allergic reactions;
- pulmonary pathologies.
Dangerous consequences of harmful fumes are frequent headaches, loss of coordination of movements up to loss of consciousness, possibly impaired liver and kidney function.
When using polyurethane foam as a basis for a mattress, up to 30 volatile chemical compounds are released into the air, and phenol is not the only one that can harm a person.
Orthopedists insist that you need to sleep on a sufficiently rigid base so that the spine is in an even position during sleep. Such a state of his can provide orthopedic mattresses with coconut coir filler, independent spring blocks.
If you press down on the thick foam rubber and release your hand, it seems that it is quite dense and tough. However, under the weight of the body, the foam rubber easily bends and the spine is in the wrong, bent position during sleep, which will eventually lead to its curvature. If you sleep on foam mattress, this can lead to dangerous degenerative changes.
Yes, sleeping on it may seem comfortable, soft, but in the morning you will be met headache, numbness of the limbs, tingling in the muscles. This is due to the foam mattress.
A mattress with a polyurethane foam filling is especially dangerous for children's health, an unformed spine of a crumb. Hazardous substances secreted by the mattress is inhaled by the child, causing chronic illness respiratory system, therefore, you should not buy a sofa or a mattress for a child with foam filling.
Almost no one knows that foam rubber is a polyurethane foam compound that was imported to the Land of Soviets by the famous Scandinavian company Porolon.
Since then, the name has stuck with it and is still practiced, since it is quite difficult to call it polyurethane foam in everyday life.
Today, when our fellow citizens are finally worried about the harmfulness of household items, it's time to write about the properties of this elastic material.
By its properties, the material is an elastic, soft foam made from polyurethane. The hollow cells contain air, which explains its very low weight.
The scope of its application is wide enough, but the main areas remain heat and sound insulation, imparting softness and elasticity to most household items, for example, upholstered furniture.
In the process of making foam rubber is used a large number of foam stabilizers, isocyanates, polyol, and catalysts. It is now generally accepted that these components can evaporate and cause substantial harm the health of those who come into contact with them. While this fact has not been confirmed, and the manufacturers themselves insist that all these components are in a bound state, so they simply cannot stand out. If they are released, then under the influence of moisture in the air, they decompose almost immediately into harmless substances.
True, in some cases, polyurethane foam can harm human health, since this substance emits highly toxic gases during combustion, therefore, the material must not be ignited.
Manufacturers to confront high temperatures thermosetting substances are added to the foam rubber, but they have not yet got rid of the flammability of the polyurethane foam completely.
It is impossible to ignore the fact that the service life of foam rubber does not exceed ten years... Further, chemical substances contained in it, begin to actively stand out in the process of decomposition of complex compounds. These substances have pronounced carcinogenic properties; therefore, it is not recommended to store polyurethane foam for more than ten years.
Polyurethane is synthetic polymer material, which is also called "plastic foam". It was first obtained in the 30s of the last century, now polyurethanes are a group of materials with wide range characteristics set depending on the requirements for the product. "Foamed plastics" are used to produce:
- parts of machines and mechanisms resistant to increased friction - polyurethane are more durable and wear-resistant than metal;
- insensitive aggressive environments connecting elements with antibacterial properties - polyurethane tubes are indispensable in the food and chemical industries;
- suitcases, backpacks, bags - polymer with "adjustable" parameters allows you to create any texture of fabric, which is used by many designers;
- leatherette for the production of clothing, footwear, gloves, belts - polyurethane "leather" lasts longer and looks more attractive than a conventional substitute made of polyvinyl chloride;
- waterproof footwear - polyurethane is stronger and more durable than artificial rubber and costs less than natural rubber.
Is polyurethane harmful?
The material is chemically and biologically neutral. It does not cause allergies, cannot serve as food for fungi and bacteria, does not absorb pollution and does not release any substances into the air. Polyurethane cannot harm health.
This polymer is widely used in the food industry. Reinforced or unreinforced, colored or transparent hose - a standard part of the units used in restaurants for preparing fresh juices, cocktails, sauces. Modern manufacturers kitchen appliances apply and recommend the use of polyurethane connectors.
How to determine the quality of a polyurethane product?
In industrial purchases, the quality of products is confirmed by a certificate. It should be studied when choosing household goods, shoes, bags, gloves. If you really like bright waterproof boots, the discount looks extremely attractive, but the seller did not have it at hand necessary documents, you can do some "tests" yourself. They do not give a 100% guarantee, but they are able to save you from buying an obviously low-quality product.
You should not buy a product that has a sharp "plastic" smell. Polyurethane does not emit any substances into the air, therefore it cannot smell. Press lightly with your fingernail on the surface of the thing, there should be no scratches or slowly rising dent. Good result- a quickly disappearing trail. In this case, the polyurethane product is most likely of high quality.
