Chloroform has the formula. Chloroform structural chemical formula. Making chloroform at home
Chloroform is an organic chemical compound whose formula is shown below. Under normal conditions, it is a colorless liquid with a sweet taste and ethereal odor. It is almost insoluble in water and does not burn.
This is a chlorinated derivative of methane, which is obtained by heating bleach with ethyl alcohol. This reaction consists of 3 parts:
You will need to assemble the device as shown in the figure below. The thermometer must be inserted into the test tube of the Wurtz flask; it must reach the bottom of the flask. Pour bleach (63.5 g) into a 0.5 liter Wurtz flask and fill it with water (250 ml). You will receive a semi-liquid mixture, to which you should add ethyl alcohol (14.5 ml). After that, close the flask with a stopper with a thermometer, and heat it on the grid, after connecting it to the refrigerator. An exothermic reaction must begin, although at first the reaction occurs without external energy supply, the temperature is constant, and the chloroform in the form of a liquid is distilled with water into the cylinder. The layer of chloroform will be under the layer of water in the cylinder. Using a separating funnel, you can separate the chloroform from the water. You should get about 20 ml of the substance.
How to obtain chloroform from ethyl alcohol
Take 430 g of bleach (with a CaO2Cl2 content of about 23.4%), mix with one and a half liters of water, adding 100 g of caustic lime and 100 ml. 88.5% alcohol. The resulting mixture is distilled. Milk of lime and calcium chloride are added to the distillate, then the separated chloroform is separated. Mix chloroform with sulfuric acid and carry out restification.
How to make chloroform from acetone
You should take 275 g of bleach and dilute it with 800 ml. water, slowly adding a mixture of 70 ml. water and 22 g of acetone.
Making chloroform from sodium and potassium hypochlorites
In this method, you electrolyze an aqueous solution of potassium chloride and alcohol (you can use acetone or aldehyde instead of alcohol). This method gives pretty good results in terms of the amount of substance released.
Electrochemical method
Platinum plates are used for the cathode and anode (the cathode should be in porous clay).
Composition of the cathode liquid: hydrochloric acid (1.19) – 30 ml.
Composition of the anode liquid: 80 g of crystalline Ba(OH)2∙8H2O, which dissolves in 300 ml. water at 50 C; 1 g. BaСl2∙2H2O.
30 ml is added to the anode liquid. alcohol A current of 2 A and a voltage of 8 V are required, with a consumed current of 6.3 Ah. The temperature is raised from 50 to 70 degrees, gradually adding alcohol. The required current density is 4 A per 100 cm2 and 10 A per 100 cm2 at the anode and cathode, respectively. The cathode liquid should also be changed. The resulting chloroform is isolated along with excess alcohol.
The discovery of many chemical substances was not intentional, but accidental, during the synthesis or study of the properties of a substance. However, many of the accidentally discovered substances became very important; they were used not only in chemistry, but also in medicine, industry and other fields. Chloroform, which will be discussed further, is one of these substances.
Name
The name of this substance has several varieties. After all, like all organic compounds, it obeys the laws of the general nomenclature of molecules, trivial names and a name based on the composition of the molecule.
Therefore, there are several possible names for chloroform:
- carbon trichloride;
- chloroform;
- trichloromethane.
Chloroform: what is it? You can understand it from the names of the compounds, or you can consider the geometric structure of the molecule.
Molecule structure
The chloroform molecule consists of three chlorine atoms and one hydrogen atom, each atom bonded to a central carbon. Essentially, the trichloromethane molecule is the product of hydrogen atoms on chlorine atoms in a methane molecule when exposed to certain conditions.
Moreover, all C-CL bonds are completely equivalent and highly polar. The C-H bond, against the background of other bonds that have appeared in the molecule, becomes even more polarized and becomes extremely vulnerable. Therefore, with further processing of the molecule, the C-H bond is easily broken and hydrogen is replaced by other atoms (for example, also chlorine with the formation of carbon tetrachloride).
Let's look at what chloroform looks like. The formula looks like: CHCL 3. The structural formula will look like this:
Both structures reflect the chemical essence that chloroform carries. The formula shows that the molecule is quite stable and strict conditions must be applied to enter into reactions.
Physical properties
The physical properties of trichloromethane can be characterized as follows:
- Under normal conditions (room temperature, normal atmospheric pressure 100 kPa, humidity not higher than 80%), this substance is a strongly odorous, colorless liquid. The smell of chloroform is quite sharp, heavy, enveloping, reminiscent of the smell of ether. The substance tastes sweet, but you should not try it, as it is extremely toxic.
- It does not dissolve in water, it can dissolve only in different types. With water it can form low-concentration (0.23%) solutions.
- The boiling point of this compound is lower than that of water, approximately 62 0 C.
- The melting point is sharply negative, -63.5 0 C.
- The density of chloroform is greater than and is 1.483 g/cm3.
- The strong, pronounced toxic nature of the substance in its effect on the body belongs to the group of narcotic compounds.
When dissolved in water, carbon trichloride is capable of forming azeotropic mixtures. In this case, the chloroform in the solution will be 97.5%, and water only 2.5%. The boiling point of such a solution is lower compared to that of pure trichloromethane and is 52 0 C.
Chemical properties
Like all chlorinated derivatives of methane, chloroform does not exhibit chemical activity. Therefore, there are few reactions that are characteristic of it. For example, treatment with chlorine molecules in the process of technological production of all methane derivatives by chlorination. To do this, liquid chloroform is taken, the reactions proceed according to a radical mechanism, requiring the presence of ultraviolet radiation as a prerequisite and light quanta.
CHCL 3 + CL 2 = CCL 4 + HCL
According to the reaction equation, it is clear that the product is completely chlorine-substituted methane - carbon tetrachloride. Such reactions are one of the ways to produce carbon tetrachloride in industry.
Chemical properties also include an azeotropic mixture with water, which chloroform can produce. What it is? That is, one in which the components of the solution do not undergo any changes when boiling. It is impossible to separate such a mixture into fractions using the boiling method.
Another type of reaction that chloroform can undergo is the replacement of halogen atoms with other atoms or functional groups. For example, when reacting with an aqueous solution, it forms sodium acetate:
chloroform + NaOH(aqueous solution) = + sodium chloride + water
In addition, a practically significant reaction is the interaction of chloroform with ammonia and potassium hydroxide (concentrated solution), since as a result of such interaction,
Chloroform + ammonia + potassium hydroxide = KCN + + water
Chloroform storage
In the light, trichloromethane decomposes to form dangerous, toxic products:
Chloroform = phosgene + hydrochloric acid + molecular chlorine + carbonic anhydride
Therefore, the storage conditions for chloroform must be special - dark glass bottles with dense ground-in stoppers. The bottle itself should be stored away from sunlight.
Receipt
Chloroform is produced in several ways.
1. A multi-stage process of methane chlorination, which occurs by a radical mechanism under the influence of ultraviolet light and high temperature. The result is not only chloroform, but also three other products: chloromethane, dichloromethane and carbon tetrachloride. The reaction looks like this:
CH 4 + CL 2 = CH 3 CL + HCL - chloromethane and hydrogen chloride are formed
CH 3 CL + CL 2 = CH 2 CL 2 + HCL - dichloromethane and hydrogen chloride are formed
CH 2 CL 2 + CL 2 = CHCL 3 + HCL - trichloromethane (chloroform) and hydrogen chloride are formed
CHCL 3 + CL 2 = CCL 4 + HCL - carbon tetrachloride and hydrogen chloride are formed
In this way, trichloromethane is synthesized in industry.
2. Interaction between bleaching lime and ethyl alcohol. This is a laboratory method.
3. Preparation of chloroform by electrolysis (action of electric current) on alkali metal chlorides in an atmosphere of acetone or ethyl alcohol. Also a laboratory method for producing trichloromethane.
Cleaning
Once chloroform is obtained, it needs to be purified. After all, if it is used for medical purposes, then the content of impurities in it is simply unacceptable. If the purpose of use is technical, then the content of foreign substances should be limited.
There may be various impurities that chloroform contains. What it is? What are they?
- Ethanol.
- Hydrogen chloride.
- Phosgene.
- Chlorine.
There are two main ways to purify chloroform from these impurities:
- abundant rinsing with water followed by drying (allows you to completely get rid of ethanol);
- trichloromethane is washed with a strong acid, then with a strong alkali, then with water. Subsequent processing consists of drying using a water-removing agent - calcium chloride. The substance is then distilled in a fractional column.
History of discovery
Since when has chloroform been known? What is it and what was it used for before? Let's try to figure it out.
The first mention of this substance dates back to 1831. It was then that trichloromethane was obtained by chemist Guthrie from Harbor. However, his goal was not this substance at all; it was a successful by-product. The chemist was looking for solvents for rubber, experimented and accidentally obtained chloroform.
In the same year and a year later, two more scientists independently obtained this substance as a result of experiments. These are Eustace Liebig (who made a huge contribution to the development of chemistry) and Eugen Suberein. Their task was to find an anesthetic, and they found it. True, they learned about this effect of chloroform and began to use it a little later, only in the 1840s.
The structural formula and interaction of atoms inside the molecule was studied and constructed by the chemist Dumas in 1834. He proposed and assigned the name to chloroform, which he gave in honor of ants. In Latin, ant is pronounced formiata, and the contents of these insects are capable of being formed from chloroform. Based on this, its name was determined.
Biological effect on humans
Chloroform fully justifies its use as an anesthetic. The effect on humans is very specific, covering several major organ systems.
The degree of impact depends on factors such as:
- concentration of inhaled substance;
- duration of use;
- way to get inside.
If we are talking about pure, medical chloroform, then its use is strictly dosed, precise and local. Therefore, of the possible contraindications, only some are implemented. If we are talking about evaporated chloroform in the air and inhalation of it by a person, then the effect here is much more serious and destructive.
So, when inhaling trichloromethane for 10 minutes, swelling of the respiratory tract, pulmonary spasms, cough, and sore throat may occur. If exposure is not stopped, poisoning will occur immediately. The nervous system (both the brain and the spinal cord) will be affected, resulting in death.
Chloroform also has a detrimental effect on the liver, digestive organs and kidneys. Its effect is especially destructive if the solution is taken orally. The following reactions of the body to taking chloroform are observed:
- dizziness;
- vomiting and nausea;
- persistent headaches;
- depression of the nervous system and, as a result, fatigue;
- elevated temperature;
- allergic rashes, redness of the skin.
Studies and experiments on different animals showed the following results:
- Long-term ingestion of chloroform orally in the form of liquid causes abortion, multiple pathologies and mutagenesis of future generations.
- When living in an atmosphere of chloroform, animals were depressed, lethargic, and their life expectancy was significantly reduced.
- Based on experiments on mice, it was concluded that trichloromethane is carcinogenic.
Such results were obtained by chemist and medical scientists when studying the effects of chloroform on living organisms.
Application in medicine
The first mention of the use of this substance for medical purposes dates back to 1847. It was then that the scientist, doctor, and chemist Holmes Coote first proposed the use of chloroform as an anesthesia. This had a positive effect on the person during the operation - complete loss of consciousness, absence of any sensations.
However, later, when the patient regained consciousness, it turned out that his nausea and vomiting did not stop. Later, more precise standards for the use of this substance were established to avoid such consequences.
The English obstetrician James Simpson played a very important role in the introduction of chloroform into medicine. It was he who proved the positive significance and effect of the compound during the birth process.
However, over time, newer, safer and more modern methods of anesthesia than chloroform have emerged. Its use in medicine has practically disappeared. Today it is used in the form:
- ointment component for external use;
- as an additional anesthetic in combination with other substances and only in very small concentrations;
- as drops to relieve nausea and vomiting.
Industrial Applications
Chloroform is also used in industry. Its use relates to various chemical syntheses, where it plays the role of a solvent, degreaser, main or additional component for the production of important substances used in all spheres of human activity.
Photo of the drug
Latin name: Chloroformium
ATX code: N01AB02; M02AX10
Active substance: Chloroformium
Analogs: no data
Manufacturer: RuiyuanGroupLimited, China (Chloroform for anesthesia); Dentalife, Australia; Tekhnokhimiya LLC, Ukraine; LLC NPP “SILUR”, Ukraine; LLC "HaloPolymer Kirovo-Chepetsk", Russian Federation; JSC "Khimprom", Russian Federation
Description is valid on: 27.09.7
Chloroform is a means for inhalation anesthesia, which is several times more powerful than ether in its narcotic effect.
Active substance
Chloroformium )
Release form and composition
The formula of Chloroform is CHCl3. Produced in accordance with the current standard GOST 20015-88 in the form of an emulsion for external use.
Indications for use
- Used for myositis or neuralgia (in the form of a mixture for rubbing).
- Oral use is allowed for hiccups, abdominal pain and vomiting (the drug is diluted with water).
- The inhalation agent is used for surgical interventions. In such cases, it is combined with a large amount of oxygen and administered in a very precise dosage.
Contraindications
- increased individual sensitivity to the components of the drug;
- skin diseases or purulent phenomena at the sites of application.
Instructions for use of Chloroform (method and dosage)
Externally, for rubbing the skin, including as a component of other drugs.
Side effects
The effect of Chloroform (when used inhalation) in the initial stage is manifested by agitation and uncoordinated movements, and then by a weakening of cardiac activity and a drop in blood pressure, which can lead to collapse or cardiac arrest.
If the vapors are swallowed, the drug can cause side effects in the form of irritation of the gastric mucosa, and with direct exposure to the vapors, severe irritation of the mucous layer of the eyes and respiratory tract can be observed.
In addition, it can provoke drug addiction - substance abuse (usually with oral abuse of the drug).
Overdose
In narcotic concentrations, Chloroform changes the rate of reflex muscle tension and metabolic processes. Causes the following symptoms:
- stomach and intestinal disorders;
- arrhythmia;
- urinary retention;
- increased concentration of sugar in urine.
Serious cases of overdose are accompanied by dysfunction of the heart and respiratory center, and damage to the mucous membranes. This is more common among employees in the pharmaceutical industry. Mild forms of poisoning are accompanied by vomiting, weakness, and dizziness.
If signs of overdose appear, the administration of anesthesia should be stopped and measures should be taken to ease the airway - mechanical ventilation, oxygen therapy, infusion-transfusion therapy.
It is recommended to warm the patient and administer hydrocortisone and dexamethasone intravenously (1 mg per kilogram of body weight). To remove toxic products from the blood, hemodialysis and hemosorption are performed. Prevention of pneumonia is recommended.
To normalize heart rate, subcutaneous injections with caffeine are indicated. camphor and cordiamine.
Analogs
Drugs with a similar mechanism of action (matching level 4 ATC code): Dimexide, Dolobene, Gevkamen.
Do not decide to change the drug on your own; consult your doctor.
pharmachologic effect
- The narcotic properties of Chloroform are manifested in a slow dulling of sensitivity, as well as depression of energy for life, which is characterized by a state of intoxication or stunned patient, which is accompanied by uncoordinated and unmotivated body movements, restlessness, clonic-tonic convulsions, delusions and illusions. The effect on plants, fungi, bacteria and animal organisms is almost the same. The properties of the drug (suspension of growth and vital activity) are equally manifested in all living beings and microorganisms.
- Chloroform anesthesia is a state of complete loss of sensitivity provoked by the influence of the above-mentioned drug. In the first stage of action of the drug, the patient may withdraw his hands or try to remove the mask. The period of arousal, its severity and duration are individual for different people - pronounced arousal is observed in alcoholics and, conversely, is absent in exhausted patients, women and children. The further effect of Chloroform on the medulla oblongata gradually inhibits reflex activity, leading to loss of muscle tone and insensitivity to stimuli (deep anesthesia).
- Another property of the drug is the dilation of the superficial blood vessels of the body, which causes severe redness of the face and an increase in temperature. As for the pupils, they narrow during anesthesia.
special instructions
Information is absent.
During pregnancy and breastfeeding
Information is absent.
In childhood
Information is absent.
In old age
Information is absent.
Drug interactions
Information is absent.
Conditions for dispensing from pharmacies
Dispensed by prescription or according to lists for medical institutions.
Storage conditions and periods
Store in a tightly closed bottle in a cool, dry place. If storage rules are violated, the substance evaporates. shelf life - 8 years.
Price in pharmacies
Information is absent.
→Attention!
The description posted on this page is a simplified version of the official version of the annotation for the drug. The information is provided for informational purposes only and does not constitute a guide for self-medication. Before using the medicine, you must consult a specialist and read the instructions approved by the manufacturer.
Chloroform is a colorless poison with a pungent odor that slowly decomposes under the influence of ultraviolet rays and oxygen. As it decomposes, chloroform is converted into other toxins: phosgene, formic acid, chlorine, etc.
Scientific research has proven that chloroform is a frequent guest in city apartments; this toxic substance poisons a person’s life day after day, destroying the immune system and health in general.
Chloroform at home
Chloroform is extremely dangerous for humans both in water and in air. In almost every house with a central water supply, the level of chloroform exceeds all permissible standards. Every day, when we take a shower or simply turn on the water, harmful substances are released into the air, because chlorine and chloroform are dissolved in tap water. Moreover, it is dissolved in very large quantities, because chlorine is a cheap and effective means for disinfecting water.
Surprisingly, during the process of taking a bath or shower, a person absorbs this poison through the entire surface of the skin, as well as through the lungs. Do not underestimate this source of danger, because skin pores, enlarged by hot water, can absorb more harmful substances than through drinking. In addition, the steam generated by hot water contains a higher concentration of chemicals than the water itself. By inhaling poisons through the lungs, the human body becomes saturated with them much faster than through the digestive tract, because in the stomach chlorinated water is partially neutralized, and chloroform enters directly into the blood through the pulmonary system.
Not only does the person taking a shower or bath suffer, the entire household experiences the harm of chloroform, because the volatile compound immediately spreads throughout the house.
Action of chloroform
Not only does chloroform negatively affect the functioning of human internal organs, it also harms the skin and hair, which become very dry after a shower. The sebaceous glands begin to work in increased mode, secreting several times more sebum than necessary, and the person soon gets what he has: oily skin and greasy hair, which must be washed daily.
Chlorine also does its dirty work from the inside, and the most common consequence of an excess of this carcinogen in the blood is an allergic reaction.
A person may break out in a rash for no reason, and the skin on the scalp begins to peel and become irritated. After many years of chlorine poisoning, something completely irreparable can happen - breast cancer. Although it is still not known for certain about the reasons that cause the growth of malignant tumors, chlorine cannot be written off, because in women with malignant tumors, doctors find one and a half times more chlorine in the breast tissue than in healthy people.
If a person inhales concentrated chloroform for more than 2-3 minutes, it can even be fatal. If a person survives such poisoning, he will feel terrible, because the substance negatively affects the functioning of the central nervous system. Vomiting, dizziness, migraine, fatigue - these are the first signs of exposure to chloroform, followed by liver and kidney diseases, and miscarriages are possible in pregnant women.
| 1.Physical and chemical properties of chloroform | 2 |
| 2.Receipt | 3 |
| 3.Use of chloroform | 3 |
| 4. Sources of release into the environment | 4 |
| 5. Migration and transformation in the environment | 5 |
| 6. General nature of the effect on warm-blooded animals | 6 |
| 7.Acute and chronic poisoning in animals and humans | 7 |
| 8.Specific and long-term effects of chloroform | 9 |
| 9. Combined and combined action | 10 |
| 10.Receipt, distribution and excretion from the body | 11 |
| 11.Hygienic standards | 13 |
| 12.Preventive measures (work safety measures) | 14 |
| 13.Environmental measures | 14 |
| 14. Emergency care for chloroform poisoning | 14 |
| 15.Conclusion | 16 |
- Physical and chemical properties of chloroform
When exposed to dilute aqueous alkali, salts of formic acid are obtained:
CHCl 3 + 4NaOH = HCOONa + 3NaCl + 2H 2 O
When exposed to concentrated alkali, carbon monoxide is formed:
CHCl 3 + 3NaOH = 3NaCl + CO + 2H 2 O
When chloroform is exposed to ammonia and potassium hydroxide, potassium cyanide is formed:
CHCl 3 + NH 3 + 4KOH = KCN + 3KCl + 3H 2 O
7. Acute and chronic poisoning
Acute poisoning. Animals:
Lethal concentrations for inhalation priming and doses for intravenous administration:
| Animals | Exposure, h | Concentration, mg/m 3 | Effect | ||
| Mice | 2 | 21 200
(26 000-17 200)
|
LK 50 | ||
| 16 000 | LK 16 | ||||
| 29 000 | LK 84 | ||||
| Mice and rats | 6 | 6 000-10 000 | LK 50 | ||
| Dogs | - | 10 000 | LK 100 | ||
| Animals | Dose, mg/kg | Effect | |||
| Mice | 620 | LD 16 | |||
| 1000 +/- 260 | LD 50 | ||||
| 1650 | LD 84 | ||||
| 2180 | LD 100 | ||||
| Rats | 800 | LD 16 | |||
| 1250
(1580
+/- 985)
|
LD 50 | ||||
| 2200 | LD 84 | ||||
| Guinea pigs | 820 +/-244,2 | LD 50 | |||
| Rabbits | 9827 | LD 100 | |||
| Dogs | 2250 | LD 100 | |||
Human: intoxication is accompanied by inhibition of the function of the vasomotor and respiratory centers, which causes collapse and asphyxia. The collapse is aggravated by the paralytic expansion of prearterioles and capillary beds as a result of the direct effect of chloroform on vascular smooth muscle. The heart rhythm is disturbed. Bradycardia. Ventricular fibrillation is possible. 1 – 3 days after exposure – dystrophic changes in the liver, kidneys, heart, which can cause death. Severe poisoning is accompanied by prolonged anesthesia, gastrointestinal disorders, jaundice, oliguria, and the appearance of sugar in the urine. Anemia, leukocytosis in the blood. Cardiovascular disorders can persist for up to 6 months. After suffering from intoxication. In mild cases, dizziness, weakness, vomiting, stomach pain.
An absolutely lethal dose is 50 ml. Individual sensitivity is noted: there are cases where taking more than 250g did not lead to death. The lowest lethal dose of chloroform indicated in the literature is 210 mg/kg body weight. Ingestion of 440 g causes gastric irritation and local intestinal necrosis. PC odor = 0.3 mg/m3; a distinct sweetish odor at 20.0 mg/m 3 .
Chronic poisoning. Animals: Experiments on rats have proven that chloroform at a dose of 5 mg/kg causes disruption of the functional state of the central nervous system, liver, kidneys, and red blood cells. Inhalation of chloroform at a concentration of 125 - 425 mg/m 3 for 7 hours daily for 6 months. Causes the development of centrilobular granulomas in the liver and tumors in the kidneys of mice and rats. Penetrates the placental barrier and has an embryotoxic effect. Rats develop tumors in the kidneys and thyroid gland, and in mice - in the liver.
Human: Chloroform causes occupational chronic poisoning with primary damage to the liver and central nervous system. Intoxication occurs with indigestion, emaciation, headaches, dizziness, irritability, and sleep disturbances. A psychotic state develops. Polyneuritis, dysfunction of the liver and kidneys, irritation of the skin and mucous membranes are observed.
8. Specific and long-term effects
Effect on animals: Histopathological changes were found in rats, guinea pigs and dogs exposed for 6 months (7 hours per day, 5 days per week) to 25 ppm chloroform. The animals exhibited fatty infiltration, granular degeneration of the central lobe of the liver with necrotic inclusions and changes in serum enzyme activity, as well as edema of the tubular epithelium, proteinuria, glycosuria and decreased phenolsulfanephtholein excretion. Narcotic concentrations for guinea pigs are 33,000 mg/m3, for cats - 30,000 mg/m3 with an exposure of 3 hours and 70,000 mg/m3 with 40 minutes; for dogs - 80,000 mg/m3. In rats exposed to chloroform at the level of narcotic concentrations for 12-24 hours, obesity and necrosis of liver cells.
In case of repeated poisoning in animals, intoxication is accompanied by emaciation and vomiting. At the level of lethal doses, chloroform is low-cumulative: Kcum = 9.62. In guinea pigs that repeatedly received 1/30 LD 50, a pronounced cumulative effect was noted. Chloroform also causes various disorders of embryonic development.
Effect on humans: At a pharmaceutical plant, among people who had contact with chloroform in concentrations of 10 - 1000 mg/m 3, 25% of those examined with work experience of 1 - 4 years had liver enlargement, and 5.6% had toxic hypatitis. Tests on volunteers (223 people) with a daily consumption of chloroform of 0.34 - 0.36 mg/kg for 1-5 years showed the absence of genatotropic effects. Chloroform is a potential human carcinogen – group 2B.
9. Combined and combined action of chloroform
Rats were intravenously administered acetone, 2-butanone, 2-pentanone, 2-hexanone, and 2-heptanone at a dose of 15 mmol/kg, followed by intravenous administration of chloroform at doses of 0.5 and 0.75 ml/kg. All studied ketones potentiated the hepatotoxic effect of chloroform. The degree of potentiation correlated with the long carbon chain of the ketone. Criteria for hepatotoxicity are the activity of ALT and ornithine carbamoyltransferase in blood plasma. Chlordecone at a dose of 50 mg/kg potentiated the hepatotoxic effect of chloroform administered intravenously at a dose of 0.5 ml/kg after 2-3 hours. The criterion for hepatotoxicity is a decrease in the level of cytochrome P-450 and B 5 in the liver, a change in the activity of ALT, AST in the blood serum. Pre-treatment with phenobarbital sharply increases sensitivity to chloroform in terms of mortality.
Combined action : The use of chloroform with oxygenation (duration of exposure 60-230 ppm, chloroform concentration 0.5-22%) revealed the phenomenon of antagonism. The combined effect of chloroform with increased air temperature (40.4-41.0 0 C) caused an increase in the toxic effect in rabbits.
10. Receipt, distribution and excretion of chloroform from the body
- Inhalation
Intrafluid (i.v.)
Through the skin
The content of chloroform in the blood of dogs during the initial manifestations of anesthesia is 30 - 40 mg%, with complete anesthesia 40 - 50 mg%; death at 60 – 70 mg%. In the blood of horses under deep chloroform anesthesia is 19.3 mg/l; 5 minutes after stopping inhalation, the chloroform content dropped to 50%, and after 3 hours - to 7% of the original. After 7 hours, chloroform completely disappeared from the blood. In humans, during operations using chloroform during the “stunning” phase - in venous blood 4 - 4.8 mg%; during the excitation stage 4.8 - 6.6 mg%, at 2 stages 10.4 - 12.6 mg%. When inhaling vapors in the first 30 minutes, 74–80% of the initial concentration is absorbed from the air by a person. Absorption then drops to 60%.
Distribution in the body is uneven. In dogs, after a 2.4-hour inhalation, maximum concentrations were in adipose tissue (282.0 mg%), in the adrenal glands (118.5 mg%), in the thyroid gland (46.0 mg%), in the brain (29.8 mg). mg%), the smallest amounts in urine (5.7 mg%). The content in the blood is approximately the same as in the brain. In erythrocytes, the concentration of chloroform is 5–8 times higher than in plasma. In mice, chloroform is stored in adipose tissue; smaller amounts in the brain, lungs, kidneys, muscles, blood. In mice in different phases of pregnancy, after 10 minutes of inhalation of chloroform, the distribution is as follows: liver > respiratory tract > brain > kidneys > placenta > fetus. 24 hours after inhalation, the chloroform content decreased by 10–100 times. In amniotic fluid, the maximum concentration was recorded after 4 hours after inhalation. The blood level drops quickly after inhalation stops, and after 7-8 hours only traces are detected.
From 30 to 50% of chloroform entering the body undergo biotransformation. In addition to the liver, a number of other organs have the ability to metabolize this poison. At the first stage, hydroxytrichloromethane HOCCl 3 is formed, which has a pronounced carcinogenic effect. At the second stage, HOCCl 3 transforms into phosgene, the main metabolite of chloroform. Transformations of phosgene proceed in three directions: hydrolysis with the release of HCl and CO 2; interaction with cysteine and the formation of 2-hydroxythiazolidine-4-carboxylate during the release of HCl; interaction with reduced glutathione and the formation through a series of intermediate stages - as final products - diglutathionyl dithiocarbamate, CO 2, HCl and the oxidative form of glutathione. In mice, the nephrotoxicity of chloroform is determined by the action of its metabolites formed in the renal cortex; this effect is absent in rats. Species differences and rates of chloroform conversion are determined within 2 days after exposure to carbon-labeled chloroform, 7-5 and 20% of chloroform, respectively, are excreted in the exhaled air; in the form of CO 2 76-79 and 66.4% of the total dose. In monkeys, the rate of biotransformation turned out to be minimal: 79-82% was released unchanged, and 10-12% as CO 2 . These data explain the pronounced carcinogenic effect of chloroform in mice, in which the rate of formation of metabolites with oncogenic effects is 20 times higher than in humans.
0.003% of the administered dose is excreted in urine and feces. It is possible to release chloroform through the skin through sweat, but the total amount of poison released this way is negligible. In the exhaled air of people who have not had industrial contact with chloroform, its content is 11 mcg/h.
11.Hygienic standards
Atmospheric air: MPC SS = 0.03 mg/m 3 ; Hazard class – 2.
Maximum permissible concentration of the working area = 20 mg/m 3
Water: VDC= 0.06 mg/l; Hazard class – 2.
12. Preventive measures (work safety measures)
Personal protection– filtering gas mask. At high concentrations - insulating rod gas masks with forced air supply. Avoid contact with skin: protective gloves, sleeves, aprons coated with polyvinyl chloride (textovit), polyvinyl alcohol, etc.
13. Environmental measures
It has been established that chloroform has carcinogenic properties (2% of the total number of diseases of liver, kidney, bladder cancer is attributed to the content of chloroform in drinking water). Therefore, purification of drinking water from chloroform is important and relevant.
To purify water from chloroform, it is effective to use 1089 active carbons of the KAU and SKD-515 brands. Due to the fact that KAU is an experimental sample of coal, for the practical implementation of the process of sorption purification of water from chloroform, we can recommend AC brand SKD-515, which is second only to KAU in adsorption capacity.
14. Emergency care for chloroform poisoning
Fresh air, peace. Prolonged inhalation of humidified oxygen using nasal catheters. Carbogen - in case of respiratory depression - repeated for 5 - 10 minutes, subcutaneous corozal (1 ml 10%). Artificial respiration “mouth to mouth” with a transition to controlled respiration when breathing suddenly weakens or stops. In severe cases - artificial kidney, extracorporeal hemodialysis.
If chloroform is taken orally, first induce vomiting (caution - aspiration); in any case, it is necessary to rinse the stomach as soon as possible (in case of sensitivity disorders, only after intubation). Then Vaseline oil, sodium sulfate and activated carbon are prescribed (2 tablespoons per 0.5 liter of water). Castor oil, milk, and alcohol are not recommended. Further therapy is symptomatic.
Wash the affected skin thoroughly with soap and water; in some cases, open (dry) management of the victim is necessary, as with burns.
The affected eye is immediately washed with running water for 10 - 15 minutes with the palpebral fissure wide open; in exceptional cases, a bandage is applied with sterile paraffin oil, and in case of severe pain - with dicaine. Follow-up with an ophthalmologist (cornea).
In all cases, hospitalization is indicated. Be careful with underestimating symptoms, pay attention to the latent period.
15. Conclusion
1.
When exposed to light, chloroform is oxidized by air, forming carbonic anhydride, hydrochloric acid, chlorine and phosgene.
2. Chloroform is used for: the production of refrigerants, plastics, artificial silk;in the pharmaceutical industry in the production of antibiotics, hormones, vitamins,cosmetics, toothpastes, as an ingredient and preservative for cough remedies;for fumigation of grain, to combat the hangar weevil, grain moth;
In medicine it was used as a means for gas anesthesia.
3.Has genatotropic, nephrotoxic and cardiotoxic effects; causes carcinogenic and mutagenic effects; irritates mucous membranes.
4. Severe poisoning is accompanied by prolonged anesthesia, gastrointestinal disorders, jaundice, oliguria, and the appearance of sugar in the urine. Anemia, leukocytosis in the blood. Cardiovascular disorders can persist for up to 6 months. Inhalation of chloroform for a long time (2-10 minutes) can be fatal.
5. The average daily intake of chloroform from food, drinking water and air for a rural resident is 14.2 mcg, for an urban resident 15.5-17.5 mcg.
6. Chloroform hazard class – 2; MPC CC = 0.03 mg/m3;
7. It has been established that chloroform has carcinogenic properties (2% of the total number of diseases of liver, kidney, and bladder cancer is attributed to the content of chloroform in drinking water). Therefore, purification of drinking water from chloroform is important and relevant.
Bibliography
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