Styrene is a colorless liquid substance with a specific odor that can harm human he alth. Currently, phenylethylene, ethylene and vinylbenzene are widely used in industry, mainly in the production of polymers and synthetic rubbers. Of course, in factories, safety precautions must be strictly observed when working with these chemicals.
Styrene production
This substance is obtained in special installations (the productivity of modern ones can reach 150-300 thousand tons of product per year) by dehydrogenation. The reaction, as a result of which styrene is synthesized, is classified as endothermic and proceeds at a temperature of the order of 600-700 degrees. In this case, an iron oxide catalyst with the addition of chromium and potassium is used. The resulting waste is processed in a multi-stage system. If the technologies of use or production are violated, styrene may be released into the environment. We will talk about what this usually has consequences a little lower. First, let's figure out what this substance is and what characteristics it differs in.
Properties
So, what is this chemical, styrene? Its properties are varied. Consider them:
- very poor water solubility;
- light oxidation;
- quick solubility in organic compounds;
- ability to easily dissolve polymers;
- polymerization to form a hard vitreous mass;
- copolymerization with monomers;
- addition of halogens.
Styrene, the smell of which is very unpleasant, can enter the human body both through the upper respiratory tract and through the gastrointestinal tract. In direct contact with liquids containing it, it can also be absorbed through the skin.
Styrene and the environment
This substance is quite harmful and can have a negative impact on living organisms. However, styrene degrades very quickly in air. Therefore, even with emergency emissions, it cannot cause much harm to nature. In soil and groundwater, styrene breaks down into its constituent substances. The same thing happens in the air when exposed to sunlight.
However, in most states, the maximum amount of this substance released into the environment by enterprises is regulated by law.
Rules for working with styrene
In the production of this substance and its use for the manufacture of polymers, of course, safety precautions should be observed. In most countries of the worldthe maximum allowable concentrations of styrenes are set in the premises where the employees of the enterprise are located. According to the rules, such workshops are recommended to be equipped with effective ventilation systems. Of course, employees of these enterprises should try not to inhale styrene fumes and use personal protective equipment if necessary.
Safety precautions should be observed when mixing with other substances (catalysts, peroxides, additives) styrene. Reactions carried out in violation of the manufacturer's instructions can be very violent or undesirable. The pouring and mixing of styrenes should be done in separate rooms designed specifically for this purpose and well ventilated.
Polymerization of styrenes occurs even at room temperature. The danger of this process is that it can be accompanied by an explosion. Therefore, this substance should be stored in accordance with the instructions.
The harm of styrene for the human body
Contact with this chemical can cause both acute poisoning reactions and chronic diseases in humans. Almost all organs - kidneys, liver, urinary, blood systems - can be affected by vapors of a substance such as styrene. How dangerous this carcinogen is for humans specifically in each of these cases, in detail, and consider below. Styrene is considered a poison of general toxic action and belongs to the 2nd hazard class. Inhalation of air containing 10,000 mg/m can be lethal for humans.3 styrene.
What acute effects can styrene cause
When the concentration of vapors in the air in the amount of 420 mg/m3 people begin to show signs of irritation of the mucous membranes of the respiratory tract and eyes. Above 840 mg/m3 nausea and drowsiness develop. At the same time, the victim has various kinds of problems with the vestibular apparatus.
Genetic changes
The mutagenic effect is another nuisance that can lie in wait for a person who inhales styrene for a long time. How dangerous is he in this regard? Judging by the research of scientists, it is quite possible that prolonged inhalation of styrene vapors can lead to an increase in the frequency of chromosomal structural aberrations in blood lymphocytes. Research was conducted on workers employed in the production of polystyrene and reinforced plastics.
Influence on playback function
Tests conducted on rodents also allow us to conclude that inhaled styrene can have an embryotoxic effect on living organisms. However, a survey of women workers in styrene factories did not reveal any particular violations.
Carcinogenic effect
Some studies have confirmed that inhaling styrenes increases the risk of developing cancers of the hematopoietic and lymphatic systems in humans. However, such an effect can only occur with very long-term (for many years) exposure to vapors of such substances.
Permissible concentrations
So weyou have considered what harm styrene can do to the human body. How dangerous this chemical product is, you now understand. Of course, in those rooms where people stay for a long time, the concentration of vapors of this substance should not exceed the maximum allowable standards. At enterprises for its manufacture or for the production of polymers and rubbers, it should be contained in the air in an amount not exceeding:
- in the working area - 30 g/m3;
- in water bodies - 0.02 g/l.
The average shift maximum allowable concentration of a substance such as styrene in the air is 10 mg/m3, the daily average is 0.002 mg/m3, single - 0.04 mg/m3.
Styrene in food packaging
Unfortunately, this substance can enter the human body not only from the environment during emissions from enterprises. Polystyrene and acrylonitrile-butadiene-styrene are actively used in the production of packaging materials intended for the transportation and storage of food products. It would seem that they should be completely harmless. However, as a result of research, it was found that styrene monomer is able to migrate into food from both soft and hard packages. In some cases, this substance even gives food, milk or juice an unpleasant aftertaste.
Styrene, which smells very unpleasant, is also used in the production of household items, building materials, etc.
Polystyrene foam damage
This material is currently one of the most populartypes of insulation. You can buy it at any hardware store, and it is used very widely, including in the construction of residential buildings. Meanwhile, expanded polystyrene is very easily subjected to destruction, decomposing by 10-15% over the entire period of service. At the same time, the content of the monomer in the decomposition products is at least 65%.
In addition, in the production of this insulation, the polymerization of styrene is very rarely complete and uniform. This means that there is always a residual amount in the granules. Therefore, styrene copolymers emit harmful vapors in any case. The fact that the use of this insulator for warming residential premises from the inside is prohibited by regulations, unfortunately, is not known to everyone. In this case, it is better to use other materials. However, you should also be aware that styrene is also contained in polystyrene. Since this substance is considered more harmful than formaldehyde, it is still better to insulate houses from the inside using mineral wool.
Vinyl wallpaper
Sometimes apartment owners are unaware that the finishing materials used for repairs contain styrene. We have already found out how dangerous this chemical product is for humans. Therefore, it is certainly worth knowing in which materials and household items it may be present. For example, a small amount of this substance is found in vinyl wallpaper. However, unlike expanded polystyrene, this type of finishing for walls in residential premises can be used. Under normal conditions, styrene from wallpaper does notstands out. In order for vinyl vapors to appear in a room pasted over with vinyl, it is necessary to increase the ambient temperature to at least 50 degrees Celsius.
ABS
Acrylonitrile butadiene styrenes are an impact-resistant resin used for the manufacture of automotive parts (manual controls, instrument panels, etc.), housings for household appliances (vacuum cleaners, remote controls, coffee makers) and electronics (processors, monitors), furniture, plumbing supplies, medical supplies, suitcases and even children's toys.
In the normal state, all these things do not pose a particular danger to human he alth. Styrene in its pure form begins to stand out from them only under the following conditions:
- Very hot.
- In medicine when used in conjunction with biomaterial.
- When using similar plastics for food storage. It is especially unacceptable to pour alcohol into containers made of such material. In this case, an effect similar to heating occurs.
Currently, styrenic polymers, including ABS, account for 50% of all commercial and engineering plastics.
What to do in case of styrene poisoning
In the event that a person has been exposed to an increased concentration of styrene vapor for a long time and has signs of poisoning, the following actions should be performed:
- Remove the victim from the contaminated room to clean air.
- When unconscious or in very poor conditionuse an oxygen mask.
- Administer artificial respiration if necessary.
- Monitor the body temperature of the victim. It should not be high or low.
If styrene comes into contact with the skin or mucous membranes, rinse thoroughly with water. The procedure should take at least 15 minutes. After its implementation, the victim must be taken to the hospital. If styrene suddenly enters the body, you must first drink a very large amount of milk or water. After this, the patient must be immediately hospitalized.
As you can see, obtaining styrene is a procedure that, if safety regulations are not followed, is far from harmless for workers. Therefore, when performing production tasks at enterprises, one should be as careful and careful as possible. You should also be vigilant when buying modern building materials, as well as food in polystyrene packages.
