Phenol poisoning. Dangerous effects of phenol on the body and symptoms of poisoning with it

What are they poisoning us with? – There’s phenol, phenol, phenol all around...

Phenols are one of the most common pollutants entering surface waters with wastewater from oil refining, oil shale processing, timber chemical, coke chemical, aniline paint industries, etc. http://www.gicpv.ru/him13-5.htm

The most unpleasant environmental moment in recent decades in Ufa was the “phenolic disaster” in 1990. The tragedy occurred due to the fault of the Ufakhimprom enterprise. The occurrence of an emergency situation was not unexpected; it could have been prevented by localizing the source of phenol distribution. Even then it became clear that there was no control over the situation in our region.

Then phenol and dioxins got into the water supply. Residents learned about the contaminated water after several days - the warning system did not work smoothly, and besides, in those days they tried to keep silent about the bad things. There were queues for drinking water. The total population consuming drinking water contaminated with phenol from the Southern water intake of the city of Ufa amounted to 672,876 people. And this is more than half of the city’s total population. The chemical composition that flowed from the tap was not even recommended for washing or washing hands. Most newborn children at that time were diagnosed with dysbiosis. Now the generation of children born during this period is called “phenolic”. http://journalufa.com/6555-ekologiya-v-ufe-i-bashkirii.-kak-nas-ubivayut.html

How did phenol get into the water supply?
- Phenol was produced at the Sintezspirt plant. It was pumped through pipes through the Birsky tract to Khimprom, where chlorophenol was produced from it. At Khimprom they started repairs, the pipes were closed with plugs, isolating them from production. The problem arose when the repairs were completed: the plugs were removed, but the pipes had not yet been connected to production. And Sintezspirt resumed pumping phenol. Several tens of tons of chemical substance spilled onto the territory.

And phenol surprisingly resembles loose ice - it merged with the lying snow. The factory workers, of course, removed what they found from the territory, but much remained. April 1990 came, the snow began to melt, phenol dissolved in the melt water and flowed into the storm drain, from there into the Shugurovka River, which flows into Ufimka. And there is a water intake on it that supplies the entire city with water. A liquid with a characteristic carbolic acid odor flowed from the taps. In the first two days, the city was generally in the dark, because the authorities did not give any explanations. Only then did we get our bearings. Under public pressure, the taps were turned off. Water began to be delivered to the city in tanks, and huge queues formed for it. http://maidanrb.blogspot.co.uk/2015/04/25.html

The media constantly mentions phenol getting into drinking water.

- Phenol was found in Ulyanovsk drinking water

In Perm, a cable company discharges phenol into the water

Yesterday St. Petersburg was shocked by the news. An exciting warning appeared that phenol had been dumped into the Neva, and therefore St. Petersburg water was dangerous to drink.

The St. Petersburg Vodokanal assured that everything was fine with the water. http://forum-spb.name/zhkh-peterburga/1065-pit-evaya-voda-v-peterburge.html

Please note: the preservative properties of smoke smoke are largely due to the presence of phenol in it. This is why many doctors consider the consumption of smoked products potentially dangerous.

It is no secret that phenol-formaldehyde resins and other derivatives of phenol and formaldehyde are used in the production of many building materials. It is also no secret that these resins gradually release volatile derivatives of phenol and formaldehyde. Many have heard that these compounds are harmful. But only a few know why they are harmful and in what doses they are permissible. But in vain.

The scope of application of phenol is extremely wide. It is also used in the production of building materials, primarily wood boards. Phenol-formaldehyde resins are found in:

• FSF plywood and laminated plywood;
• Fiberboard of some brands;
• some adhesives;
• synthetic varnishes.

Uncured phenol-formaldehyde resin contains up to 11% free phenol.

Phenol is also used in the production of polycarbonates and epoxy resins. The content of free phenol in them can be quite high.

Formaldehyde

gaseous substance with a pungent odor. In industry, an aqueous solution of formaldehyde is usually used - formalin (stabilized with methanol) or methanediol (without methanol).

FK plywood can be recognized by the light adhesive layers of urea-formaldehyde resin. This resin contains formaldehyde, but does not contain phenol.

Formalin can cause denaturation of proteins, due to which it is used as an antiseptic in medicine (of course, in a very weak solution), as well as in the creation of anatomical preparations.

In industry, formaldehyde is used very widely - primarily for the production of synthetic resins (phenol-formaldehyde, urea-formaldehyde, melamine-formaldehyde). In addition, it is used in very small quantities in the production of cosmetics and some pharmaceuticals.

Formaldehyde itself is a fairly strong poison. It irritates the mucous membranes and has a destructive effect on the respiratory tract. When formaldehyde enters the bloodstream (through the respiratory system or as a product of methanol oxidation), it seriously affects the nervous and reproductive systems, as well as the eyes.

Carcinogenicity of phenol and phenol-containing agents (alflutop, vaccines, cosmetic peels)

According to " IARC Monographs on the Evaluation of Carcinogenic Risks to Humans » ( WHO, International Agency for Research on Cancer), pure phenol in the form of liquid and vapor or contained in other products (cosmetic peels, alflutop) can affect the eyes, skin, respiratory tract and nervous system of humans. Repeated or prolonged skin contact with phenol causes dermatitis, up to second and third degree burns. Inhalation of phenol vapor leads to pulmonary edema. The substance may have adverse effects on the central nervous system and heart, leading to arrhythmias, seizures and ultimately coma. Long-term or repeated exposure to the substance, as in the case of aflutop, may have adverse effects on the liver and kidneys. The toxicity of phenol is determined by hydrophobic effects and the formation of phenoxyl radicals. It is especially dangerous when phenol is mixed with chloroform (this mixture is usually used in molecular biology to purify DNA and RNA).

Phenol poisoning occurs during its production and use, as with the use of phenolic resins in the wood industry. It is also found in automobile exhaust and tobacco smoke.

• Oncogenicity in humans:

A study of Finnish carpenters found a high risk of lung cancer in people exposed to phenol, although the risk was greater in short-term workers. This finding was not replicated in three other studies that tested the association of phenol with lung cancer, although two of them had very low statistical power. However, all subsequent studies either showed an association of phenol with cancer of various sites, or reported an increased risk of cancer, but only of certain sites.

• Oncogenicity in animals :

Phenol was tested for carcinogenicity by oral administration in rats and mice. An increased incidence of leukemia was observed in male rats at low concentrations, but not in rats at high dosages or in female mice and rats. Phenol promoted tumorigenesis in mouse skin in a two-step protocol.

Phenol is well absorbed from the gastrointestinal tract and through the skin of animals and humans. It is metabolized primarily by conjugation (sulfation and glucuronidation) or, to a lesser extent, by oxidation, forming quinone-like reactive intermediates that are able to covalently bind to proteins and are detoxified by conjugation to glutathione. Topically applied phenol causes skin irritation, and systemic toxicity in the form of liver and kidney damage can occur after topical and oral dosing.

Following in vivo administration, phenol causes nuclear breakdown in mice and chromosomal aberrations in rats. It also induces oxidative DNA damage in mice, and binds covalently to DNA in rats. In cultured mammalian cells, phenol causes mutations, sister chromatid exchange, and the formation of micronuclei. It binds to intracellular protein (but not DNA) and inhibits intercellular communication.

Formaldehyde and its aqueous solution - formalin is a known carcinogen (i.e. a substance that causes cancer). Used in agriculture as a germicide, fungicide and insecticide. Penetrating into the digestive tract it causes symptoms of severe poisoning - severe abdominal pain, vomiting with blood, protein in the blood and urine, kidney damage, resulting in cessation of urine output, acidosis, coma and death. http://www.rifinfo.ru/news/7371

So a city resident living in an apartment filled with phenols from furniture and paints, breathing phenols, drinking phenols, consuming medicines with phenols “for joints”, doing Mantoux tests, can hardly be healthy and can hardly have healthy children, if at all to have children.

Of course phenol is a poison. Therefore, it is used as a preservative to prevent the infection from multiplying.

Phenol kills microbes, which is why it is introduced into vaccines so that they do not settle there.

Phenol is also used in cosmetics, creams, and shampoos. Phenol and its derivatives easily penetrate the human body through the skin

Even such delicious green apples do not spoil for a long time precisely because they are treated with phenol. Wash the apples thoroughly, or better yet, cut off the peel. Of course, this also applies to other fruits.

Many, many foods contain phenol.

Phenol is also contained in building materials,

in any where synthetic or plastic adhesives are used: in chipboard, fibreboard, OSB, in plywood, in thermal insulation boards, in linoleum, in laminate, a little in vinyl wallpaper, in suspended ceilings, in the plastic that is on windows, in panels PVC, in almost all of our kitchen oilcloths, etc., we live in the age of chemistry, we can’t live without it. And since our furniture is made of sawdust mixed with glue, that is, it is made of fiberboard, chipboard, MDF boards, then there is also enough of it in furniture, often even more than in building materials.

Phenol vapors are poisonous. They have a specific smell (such as the smell of gouache, since gouache contains phenol).

Some nasal and ear drops contain phenol.

Even in the human body, phenol is formed during metabolism and excreted in the urine. The mechanism is not clear to me.
Some microorganisms living in the intestines produce phenol.

It is clear that all poison and all medicine, and depends only on the dose. No one has canceled the maximum concentrations.

I don’t want to administer phenol to my child again. You always need to evaluate the benefit-harm ratio.

For example, Mantoux, Diaskintest, containing phenol, detect patients with tuberculosis. You can also do PCR. This blood or saliva is taken for analysis.
In theory, it’s probably better to do PCR. At least no bullshit is introduced into the body. I just don’t know how informative it is, and whether it is accepted as a replacement for Mantoux. I found about PCR

Order No. 64 of February 21, 2000 “On approval of the nomenclature of clinical laboratory tests” states very clearly that the Ministry of Health of the Russian Federation recommends PCR as an alternative method of testing for tuberculosis, clause 9.4.5 of the appendix. The high efficiency of this method is also stated there.

Polymerase chain reaction (PCR), based on the detection of a DNA section characteristic only of a given pathogen, can serve as one of the methods for rapid diagnosis of tuberculosis. The high sensitivity of PCR allows you to detect single cells or even DNA fragments of the pathogen in the test material within 4-5 hours. PCR makes it possible for differential diagnosis in limited forms of tuberculosis (focal infiltrates, tuberculomas, tuberculosis of the intrathoracic lymph nodes), as well as in the disseminated form of tuberculosis, in which differential diagnosis using only traditional microbiological methods is very difficult due to the rare detection of the pathogen in sputum. Summarizing the results of bacterioscopy, inoculation on solid nutrient media and PCR testing of material obtained from patients with limited forms of tuberculosis, we can conclude that the latter has a significantly higher sensitivity compared to traditional methods. PCR is highly informative when it is necessary to confirm the diagnosis of tuberculosis in children and adolescents with negative results from traditional microbiological research methods. The use of PCR in the diagnosis of tuberculosis is recommended by the Ministry of Health of the Russian Federation (order No. 64 dated February 21, 2000 “On approval of the nomenclature of clinical laboratory tests”, clause 9.4.5 of the appendix).
http://www.mamakazan.ru/forum/viewtopic.php?f=80&t=15006

Although no one can give a 100% guarantee of the absence of the disease.

I don't want to make Manta anymore. A 10-year-old boy has a constantly positive reaction. The tuberculosis clinic diagnosed an allergy, but they didn’t stop doing Mantoux. No information content. And I'm worried. You should at least ask for a general blood test. It will still show whether there is inflammation or not.

In general, I’m surprised why not first do a general blood test for everyone to determine whether there is inflammation. For example, with tuberculosis there is an increased content of monocytes in the blood.
Of course, an increase in monocytes can also occur in other diseases, then it can be diagnosed using other methods (diaskin test, Mantoux, PCR)

Allergies are considered the plague of the twenty-first century. More than a third of people in the world are susceptible to this disease. As soon as the allergen enters the body, antibodies appear.

Initially, harmless, passive antibodies, when a subsequent, re-entered allergen, combine with it in cell membranes and rupture these membranes. Histamine molecules are released from the cells. They cause skin diseases - urticaria, inflammation of the mucous membrane, lung disease - bronchial asthma. A violent reaction of antibodies to allergens can lead to death. One of the main allergens is phenol.

Phenol compounds are dangerously poisonous. Especially when inhaling toxic vapors of phenol-containing dust. Phenols easily enter the body from the air through the skin, lungs and stomach, causing the following allergic diseases: swelling of the nose - rhinitis, redness and painful swelling of the eyes - conjunctivitis, diseases of the upper respiratory tract - bronchospasms, shortness of breath and wheezing, asthma attacks .
Ear disease may occur - swelling, pain, and hearing loss.

Skin diseases caused by allergies include eczema, urticaria, and dermatitis. In some cases of allergies, severe headaches occur. With a violent response of antibodies to phenol allergens, anaphylactic shock can occur - bronchospasm, edema.

A person exposed to carbolic acid for a long time gets many severe, often irreversible, diseases: allergies, diarrhea, mouth ulceration, toxic hepatitis. The gastrointestinal tract may be damaged, but the work of the kidneys is most severely damaged, as they remove phenol from the body.

With prolonged exposure to phenol, poisoning occurs, destruction of the nervous system and, as a result, respiratory tract paresis and death of brain cells can occur. That is why, if you notice symptoms of an allergic reaction to phenol, or if signs of phenol poisoning appear, such as a skin rash, burning in the mouth, vomiting, difficulty breathing or swallowing, or swelling, you should immediately contact a medical facility.

Where is phenol “hiding”: sources of infection

We have been living in a phenolic environment for a long time. The toxic composition can be found in building materials, carpeting, clothing, toys and food. It is definitely present in household chemicals. The presence of phenol can be noticed by the smell, sweetish, reminiscent of gouache, some say that the smell is “like in a pharmacy.” It is the vapors of phenol, even at the most normal temperature, that cause allergies.

The main sources of phenol can be building materials such as certain types of particleboard products (chipboard) and fiberboard. The polymer material used to finish floors, walls, as well as decorative plastics used to decorate windows and doors can also be a source of phenol allergy.

From such items, phenol can be released for several years. Varnishes and paints in the apartment and plastic windows, baseboards, wall panels, any polyvinyl chloride products also often poison us with phenol: linoleum, laminate, vinyl wallpaper, and other floor coverings contain phenolic dyes. Phenol may be present in insulation materials: artificial mineral wool, for example, is “famous” for its high content of this substance.

Furniture made from fiberboard and chipboard, when exposed to heat, is even more toxic than building materials. Decorative film, adhesive materials, upholstery materials, varnish and enamel used in the manufacture of furniture contain phenol.

Clothing from Bangladesh, Sri Lanka, Cambodia, made from fabrics with dyes containing phenol, is also very dangerous.

Among home care products, the most allergenic dyes are all kinds of fragrances, as well as crumbly elements that create powdery dust.

Cosmetics, like household chemicals, contain fragrances and preservatives, and these are phenol and other harmful substances to extend shelf life.

Children's products, mainly Chinese and Taiwanese, manufactured illegally, are also sources of phenol. Phenols and formaldehyde are found in unacceptable concentrations in children's rubber, latex, plastic and soft toys. In the manufacturing process of such products, phenol is used to shape plastic and rubber.

Smoke can become a source of phenol allergy. Cigarette smoke contains phenol as a disinfectant, along with other carcinogens.
When heated, plastic dishes release toxic substances, including phenol, poisoning the human body.

Phenol is present in drinking water and air.

Sofas, clothes, household appliances, dishes, toys, cosmetics, and household chemicals soaked in phenol can somehow be excluded, but worst of all, food and medications containing phenol. When using medical products and consumer products containing phenol, a person is exposed to much greater poisoning.

A person swallows such drugs, rubs them or applies them to the skin. Numerous disinfectant ointments, nasal drops, ear drops, and herpes lotions, mouth and throat rinses, toothache drops, and antiseptic lotion all contain carbolic acid. Aspirin, antiseptics, and pesticides from the pharmacy are all phenol.

The peels of oranges, apples, and bananas treated with phenol-containing preparations prevent rotting of the fruit. Many other additives are also used in the food industry with good intentions in manufacturing, processing, preservation, and disinfection, but almost all of them are poisonous and cause allergies if they contain phenol.

Types of allergies to phenol

Allergy:

Allergy from the smell and particles of phenol in the air is respiratory. The reaction occurs when dust, pollen, gases, and perfume odors containing phenol enter the body from the air. Symptoms of respiratory allergies are a runny nose, accompanied by itching in the nose, a person sneezes and coughs.

Bronchial asthma is also classified as an allergic disease. Allergic reactions - lacrimation, pain and itching in the eyes are caused by volatile phenols present in the air. With such an allergy, unlike colds, the body temperature does not rise. A child suffering from bronchial asthma can be killed by phenolic compounds.

Contact allergies:

Statistics place contact allergies in second place, after respiratory ones: dermatoses caused by the use of cosmetics, pharmaceutical products, household chemicals, latex. Symptoms of allergic dermatoses are rashes and itching on the skin. The skin turns red, swells, blisters and peeling appear. The rash is usually small and watery, similar to hives.

Respiratory allergies and contact dermatitis are usually recognized 15 or a little later after inhalation or skin contact.

And allergies:

Drug and food allergies usually develop within a day. Signs of food allergies can be: allergic skin lesions, dermatitis, urticaria, Quincke's edema. In addition, gastrointestinal disorders - vomiting, nausea, diarrhea, constipation, flatulence and respiratory disorders - rhinitis, asthma.

Phenols are present in almost many products, such as salicylates. The body of some children is not able to process phenols into useful substances. Salicylates accumulate to a point that causes allergies. Some people cannot tolerate even natural salicylates of healthy products. The reaction to them, in those who are especially sensitive, can be as severe as when using synthetic additives.

With a drug allergy, the most severe case can occur - anaphylactic shock. The person loses consciousness, has difficulty breathing, the body cramps, and a rash may appear on the body. If you suspect the onset of anaphylactic shock, you should immediately call an ambulance. Anaphylaxis can develop within one minute to several hours from the start of contact with allergens.

The main danger of phenol

Phenol is a poison, in excess doses, which causes irreversible damage to many organs. If it enters through the air, it can leave burns that can lead to pulmonary edema.

Basic properties

The substance has moderate solubility in water (when heated to 700 degrees - in any proportion), and good in oils, alcohol-containing liquids, acetone and alkalis. When interacting with water vapor, it becomes volatile.

Sources of poisoning

The wide range of applications leads to the likelihood of a high frequency of cases of intoxication.

More than 40% of the substance is used in the chemical industry for the production of other organic compounds, in particular resins.

Scope of application

The properties of a substance are used in the following areas:

• chemical industry: in the production of synthetic fibers, various solutions with cleaning and disinfecting properties, dyes;
• oil refining sector: for selective purification of various oils;
• agricultural industry: for disinfection of livestock, treatment of plants against diseases and protection against weeds;
• woodworking sphere: as an additive to glue and wood;
• food industry: to ensure the preservative abilities of smoke smoke;
• cosmetology area: for peeling;
• pharmaceuticals: as a preservative in solutions for vaccines, in the manufacture of medicines;
• medical field: a solution of phenol in water, as an antiseptic, a remedy for the treatment of fungal diseases of the skin, genital warts, inflammation of the ear, as a disinfectant solution for caring for the sick, for linen, and for cleaning premises.

Degree of toxicity

Phenol is very toxic and sometimes causes irreparable harm to overall health.

It is classified as hazard class II. The degree of exposure of phenol to the human body is quite high.

The substance enters the body in several ways, in particular through the respiratory organs and the surface of the skin, as well as the mucous membrane. And it is eliminated by the kidneys and, by inhaling vapors, through the lungs.

Pharmacodynamics

In addition to being antiseptic, it has a bactericidal effect on vegetative forms of bacteria and fungi. The weak effect of phenol on spores is due to its insufficient solubility in water. Has disinfecting abilities.

It binds with the proteins of the infected cell, causing destruction of their native structure and the colloidal property of the cell. In addition, the substance dissolves in the membrane lipids of the infected cell, increasing its permeability and affecting the oxidative-regenerating internal processes.

In a liquid of 1.25% concentration, most of the microbes die after 5-10 minutes at room temperature.

The bactericidal effect is enhanced at higher temperatures, in acidic conditions.

Pharmacokinetics

The drug is easily absorbed through the surface of the skin, as well as mucous membranes, and is perfectly adsorbed by food products. Very toxic if absorbed systemically.

About 20% of the dose taken is subject to oxidation. The end products of metabolism are phenyl glucuronide and phenyl sulfate. The oxidation products are catechols and quinols, mainly conjugated. Metabolic products are eliminated by the kidneys, and quinones give the urine a dark brown or greenish tint.

Only a small amount of the substance is eliminated as a “free” element. Considering the fact that free phenol is concentrated in the bloodstream, toxicity is directly related to this.

Possibility of intoxication

Toys that do not comply with GOST standards can lead to poisoning

The causes of phenol poisoning are non-compliance with instructions and safety rules when working with the substance, violation of the dosage regimen during treatment, violation of regulations for the storage of phenol-containing drugs, the use of plastic toys by children that do not comply with GOST indicators, etc.

The likelihood and danger of poisoning for a child is that the substance smells like gouache, which provokes a situation of accidental ingestion by children.

People working in industries where phenol is used are at primary risk because of the increased risk of inhaling vapors.

Acceptable average daily norms

In the process of contact with the surface of the skin, even in the absence of damaged areas, it is quickly absorbed. Within minutes, the toxic effect on the brain appears.

The lethal norm for a healthy adult when administered orally is considered to be within the range of 1-10 g, and for therapy in children - 0.03-0.5 g.

A poisonous effect on almost all cells is possible due to structural changes in protein molecules, accompanied by a violation of their properties and the loss of cellular proteins in the form of sediment. This is fraught with the development of tissue necrosis.

The maximum permissible dose in the air is 0.01 mg/m3, remaining in it for an hour.

The average daily dose in the air is 0.003 mg/m3.

Symptoms

The harm of phenol exposure to humans is obvious. Noting why the drug is dangerous, we should mention its ability to penetrate the blood-brain barrier and spread through the bloodstream to all tissues and cells of the body.

Symptoms characterizing phenol poisoning are as follows:

• Initially, the victim experiences slight excitement, which quickly passes and is replaced by irritation. Later, a state of apathy, indifference and depression develops.
• Loss of strength and weakness are growing dynamically. Tactility decreases, while the reaction to changes in illumination intensifies. The poisoned person experiences a feeling of nausea, dizziness, and severe headaches. Convulsions and loss of consciousness are possible.
• The skin turns pale and becomes cold to the touch. Sometimes there is cyanosis of the skin.
• When inhaling fumes, shortness of breath develops and breathing becomes rapid. Constant sneezing is caused by irritation of the nasal mucosa. As the degree of toxemia increases, spastic phenomena in the larynx and a dry cough occur. In cases of severe toxemia, spasms of the trachea and bronchi are possible, which can lead to suffocation and death.

Relief measures

Due to the risk of developing spastic contractions of the bronchi and other negative phenomena, calling a team of professionals is justified in any case of phenol poisoning. Before her arrival, primary care should be started immediately.

Pre-medical actions

If signs of poisoning by a substance are observed, it is urgently necessary to interrupt the victim’s contact with poisons. To do this, he is taken outside and freed from restrictive clothing. If the substance gets on the skin, wash it thoroughly with water.

In case of contact with skin, rinse with water.

If phenol poisoning occurs orally, treatment does not begin with medication. First you should rinse your mouth for 10-15 minutes.

If phenolic liquid penetrates into the stomach, sorbent preparations can be taken.

Gastric lavage procedure is not allowed. This is due to the risk of increasing the degree of burn, and will increase the location and extent of damage to the mucous membrane.

In a hospital setting

Further actions will be carried out by medical professionals. Where does treatment begin? The victim will be given an antidote. The drug calcium gluconate serves as an antidote.

To remove phenol from the body and prevent further harmful effects, the clinic uses the following basic procedures:

Calcium gluconate

• hemosorption is the process of circulating blood in a specialized apparatus;
• detoxification - the introduction of solutions that reduce the concentration of a toxic component in the bloodstream and promote its natural elimination through the kidneys;
• hemodialysis is the process of blood passing through a machine, through special membrane-like formations that trap toxins.

Additional treatment depends on which symptoms persist. They consist of procedures to restore the structure of the skin, the activity of the central nervous system and cardiovascular system, etc.

1. Phenols- derivatives of aromatic hydrocarbons, in the molecules of which the hydroxyl group (-OH) is directly bonded to the carbon atoms in the benzene ring.

2. Classification of phenols

One-, two-, and trihydric phenols are distinguished depending on the number of OH groups in the molecule:

In accordance with the number of condensed aromatic rings in the molecule, phenols themselves are distinguished (one aromatic ring - benzene derivatives), naphthols (2 condensed rings - naphthalene derivatives), anthranols (3 condensed rings - anthracene derivatives) and phenanthroles:

3. Isomerism and nomenclature of phenols

There are 2 types of isomerism possible:

• isomerism of the position of substituents in the benzene ring

• side chain isomerism (structure of the alkyl radical and number of radicals)

For phenols, trivial names that have developed historically are widely used. The names of substituted mononuclear phenols also use prefixes ortho-,meta- And pair -, used in the nomenclature of aromatic compounds. For more complex compounds, the atoms that make up the aromatic rings are numbered and the position of the substituents is indicated using digital indices

4. Molecule structure

The phenyl group C 6 H 5 – and hydroxyl –OH mutually influence each other

• The lone electron pair of the oxygen atom is attracted by the 6-electron cloud of the benzene ring, due to which the O–H bond is even more polarized. Phenol is a stronger acid than water and alcohols.

• In the benzene ring, the symmetry of the electron cloud is disrupted, the electron density increases in positions 2, 4, 6. This makes the C-H bonds in positions 2, 4, 6 more reactive. and – bonds of the benzene ring.

5. Physical properties

Most monohydric phenols under normal conditions are colorless crystalline substances with a low melting point and a characteristic odor. Phenols are slightly soluble in water, readily soluble in organic solvents, toxic, and when stored in air they gradually darken as a result of oxidation.

Phenol C6H5OH (carbolic acid ) - a colorless crystalline substance oxidizes in air and becomes pink; at ordinary temperatures it is sparingly soluble in water; above 66 °C it is miscible with water in any proportions. Phenol is a toxic substance that causes skin burns and is an antiseptic.

6. Toxic properties

Phenol is poisonous. Causes dysfunction of the nervous system. Dust, vapors and phenol solution irritate the mucous membranes of the eyes, respiratory tract, and skin. Once in the body, Phenol is very quickly absorbed even through intact areas of the skin and within a few minutes begins to affect brain tissue. First, short-term excitement occurs, and then paralysis of the respiratory center. Even when exposed to minimal doses of phenol, sneezing, coughing, headache, dizziness, pallor, nausea, and loss of strength are observed. Severe cases of poisoning are characterized by unconsciousness, cyanosis, difficulty breathing, insensitivity of the cornea, rapid, barely perceptible pulse, cold sweat, and often convulsions. Phenol is often the cause of cancer.

7. Application of phenols

1. Production of synthetic resins, plastics, polyamides

2. Medicines

3. Dyes

4. Surfactants

5. Antioxidants

6. Antiseptics

7. Explosives

8. Preparation of phenol V industry

1). Cumene method for producing phenol (USSR, Sergeev P.G., Udris R.Yu., Kruzhalov B.D., 1949). Advantages of the method: waste-free technology (yield of useful products > 99%) and cost-effectiveness. Currently, the cumene method is used as the main method in the global production of phenol.

2). Made from coal tar (as a by-product - the yield is small):

C 6 H 5 ONa + H 2 SO 4 (diluted) → C 6 H 5 – OH + NaHSO 4

sodium phenolate

(product ofresin bootscaustic soda)

3). From halobenzenes :

C 6 H 5 -Cl + NaOH t , p→ C 6 H 5 – OH + NaCl

4). Fusion of salts of aromatic sulfonic acids with solid alkalis :

C 6 H 5 -SO 3 Na+ NaOH t → Na 2 SO 3 + C 6 H 5 – OH

sodium salt

benzenesulfonic acids

9. Chemical properties of phenol (carbolic acid)

I . Properties of the hydroxyl group

Acid properties– expressed more clearly than in saturated alcohols (the color of the indicators does not change):

• With active metals-

2C 6 H 5 -OH + 2Na → 2C 6 H 5 -ONa + H 2

sodium phenolate

• With alkalis-

C6H5-OH + NaOH (water solution)↔ C 6 H 5 -ONa + H 2 O

! Phenolates are salts of weak carbolic acid, decomposed by carbonic acid -

C6H5-ONa+H2O+WITHO 2 → C 6 H 5 -OH + NaHCO 3

In terms of acidic properties, phenol is 10 6 times superior to ethanol. At the same time, it is the same number of times inferior to acetic acid. Unlike carboxylic acids, phenol cannot displace carbonic acid from its salts

C 6 H 5 - OH + NaHCO 3 = the reaction does not occur - although it dissolves perfectly in aqueous solutions of alkalis, it actually does not dissolve in an aqueous solution of sodium bicarbonate.

The acidic properties of phenol are enhanced under the influence of electron-withdrawing groups associated with the benzene ring ( NO 2 - , Br - )

2,4,6-trinitrophenol or picric acid is stronger than carbonic acid

II . Properties of the benzene ring

1). The mutual influence of atoms in the phenol molecule is manifested not only in the behavior of the hydroxy group (see above), but also in the greater reactivity of the benzene ring. The hydroxyl group increases the electron density in the benzene ring, especially in ortho- And pair- positions (+ M-OH group effect):

Therefore, phenol is much more active than benzene in electrophilic substitution reactions in the aromatic ring.

• Nitration. Under the influence of 20% nitric acid HNO 3, phenol is easily converted into a mixture ortho- And pair- nitrophenols:

When concentrated HNO 3 is used, 2,4,6-trinitrophenol ( picric acid):

• Halogenation. Phenol easily reacts with bromine water at room temperature to form a white precipitate of 2,4,6-tribromophenol (qualitative reaction to phenol):

• Condensation with aldehydes. For example:

2). Hydrogenation of phenol

C6H5-OH + 3H2 Ni, 170ºC→ C 6 H 11 – OH cyclohexyl alcohol (cyclohexanol)