formic aldehyde or formaldehyde - a colorless gas with a sharp, unpleasant characteristic smell.It is highly soluble in water and alcohol.Formaldehyde is highly toxic and can cause in the human body pathological changes.In addition, he is considered a carcinogen.
Formaldehyde - the first member of a homologous series, which includes aliphatic formic aldehyde.Formic acid also exhibits the characteristics of this group.
chemical properties
Formaldehyde is able to enter into all the reactions that are inherent in the homologous series of aliphatic aldehydes.Including with nucleophiles.It also communicates with the reducing agents.This is mainly due to the fact that formaldehyde is low electron density on the carbon atoms.Due to this feature of the structure it is very easy to enter into chemical reactions with even the most weak nucleophiles.This explains the fact that in aqueous formic aldehyde is found in a hydrated state.
Production obtain
This matter is quite simple formula.Formic aldehyde for chemical language is as follows: HCHO.The main industrial method of receipt - is the oxidation of methanol.This reaction is carried out using a silver catalyst.The required temperature - 650 degrees.The oxidation of methanol takes place at atmospheric pressure.
This process is already quite a long time is used everywhere.He is well-developed.Approximately 80% of formaldehyde was prepared through an oxidation reaction of methanol.However, this is not the only way.A recently developed method is even more promising.It is based on the use of iron-molybdenum catalysts.This lowers the level of the desired temperature to 300 degrees, and it is practically halved.
also known for another industrial process - the oxidation of methane.In reaction to this rather simple formula: formic aldehyde is obtained at a pressure of 1.2 MPa at a temperature of 450 degrees.The catalyst taken aluminum phosphate.
Application
Metandiol - aqueous solution of formaldehyde, which causes protein denaturation.It is the quality of the substance can be used as a tanning agent in the manufacture of leather items.It is also widely used in the manufacture of Film-films.Because of the strong tannins properties formaldehyde is known as an antiseptic.It is widely used in medicine.On its basis the antiseptic preparations such as "Formagel" and "Formidron".For quite a long time, formic aldehyde is used in biology for the storage of biomaterials, such as bodies or dead animals.
Currently obtaining formic aldehyde profitable wood and, of course, the furniture industry.It is used for the production melaminokarbamidoformaldegidnyh resins.They are used in the manufacture of particle board, plywood and other building materials.
When storing formic aldehyde should be noted that at temperatures below 10 degrees the solution becomes cloudy and a white precipitate appears.Also, formaldehyde is reacted with oxygen.As a result, for reasons of additional degenerate branching chain initiators.
toxic properties
Now, formaldehyde is produced by the oxidation of methanol and methane.Undoubtedly, it has a sufficiently high degree of toxicity.Formic aldehyde primarily affects the genetic material.From this substance suffer reproductive organs.But, of course, often marked the defeat of the respiratory tract, skin and mucous eye.
Harmful formaldehyde by the fact that it has a negative effect on the CNS.
formic aldehyde is not just toxic - 60-90 ml of material (depending on body weight), trapped inside, cause death.Symptoms of poisoning following:
- general breakdown;
- pale skin;
- unconsciousness;
- CNS depression;
- shortness of breath;
- severe headache;
- cramps, especially at night.
impact of formic aldehyde in the human body
Application of formic aldehyde in the production often causes varying degrees of poisoning among employees.With strong inhalation lesions, ie by inhalation, observed conjunctivitis and acute form of bronchitis, which sometimes leads to pulmonary edema.Symptoms by prolonged exposure to formaldehyde will only increase.After a short time, and there will be signs of CNS depression.This will be expressed in constant dizziness, feeling of fear arises, gait becomes shaky, and at night a person can be even seizures.
If the poisoning occurred through the mouth, the first symptom will burn the mucous membrane of the digestive tract.It will manifest itself in the form of pain, a burning sensation in the throat and the esophagus.Man feels strong retching, weight, stomach rejects will contain blood.In severe cases, edema of the larynx and respiratory arrest occurs reflex.
In chronic poisoning in small concentrations in humans there is a strong weight loss, mental stimulation, visual disturbances, insomnia and chronic headaches.
poisoning with formaldehyde
formic aldehyde is most often found in the air.Employees of enterprises engaged in work related to the manufacture of synthetic resins, with a permanent and long-term exposure to formaldehyde vapors possible poisoning.Often in the first working days of a person marked dermatitis appear on the face, hands.The presence of formaldehyde in the body can be seen on the deterioration of nails - they soften and become brittle.
eczema and dermatitis may be of allergic character.After a person has suffered poisoning, he formed a strong sensitivity of formic aldehyde.There is evidence that formaldehyde adversely affects the functioning of the reproductive system of the female body.
use of formaldehyde in cosmetics
Formaldehyde is permitted as a preservative in cosmetics, but its concentration should not exceed 0.1%.Formic aldehyde may be present in toothpaste, body cream, face and hands.
also in pharmacology, some means of preventing excessive sweating can is formaldehyde.His allowable concentration - 0.5%.This substance - a good antiseptic, even in such small quantities it is capable of destroying micro-organisms.It is strictly forbidden to put any ointment on the face, if it is part of a 5% formaldehyde.It is fraught with the appearance of dermatitis and allergic reactions.Formic aldehyde is not used for the preservation of cosmetic products, if they are marketed as aerosols and sprays.
All products on its label should contain information on the content of dangerous substances, even if the amount of 0.05%.In fact, to this day do not find out how the formaldehyde solution to the skin, but it is known that animals she blushes and flaky.
Carcinogenicity formic aldehyde
known that formaldehyde reacts with selenium, with the participation of highly concentrated sulfuric acid.The result is a 4-sulfoefir tetradetsilidioksan.This substance with a complicated name after treatment with barium hydroxide becomes beautiful detergent.It would seem, what's the danger?But formaldehyde is added to the list of substances with carcinogenic properties.Although the degree of danger it is not established, it is necessary to take into account the fact that the formic aldehyde is deadly for animals.According to official data of many scientific centers of the world, the relationship between the use of formaldehyde in the manufacture of paints, resins, textiles, plastics, and the occurrence of cancer tumors in humans is proved.Especially high risk of developing cancer of the nasopharynx.
