Chemistry has endowed humanity with a mass of useful compounds, greatly facilitating life and opening up many new areas previously unknown to people. Among the necessary substances, sodium sulfite also appears, which has found its application in very diverse branches of human activity.
Chemical and physical properties
Sodium sulfite (anhydrous version) is a white powder, sometimes with a yellowish tinge. It doesn’t burn, does not have the ability to explode, but it decomposes when heated, forming poisonous gases, and therefore it was assigned to the 3rd hazard class. The decomposition products that sodium sulfite forms can disrupt the central nervous system, cause fainting when inhaled, reduce the ability to breathe, excessively accelerate the heart rhythm, and cause damage to bones, skin and eyes. That is why in the event of a fire where sodium sulfite is stored, it is necessary to enter it as protected as possible: in a special suit and always with a breathing apparatus. If the substance is scattered, this place should be fenced with a side from the ground, the powder itself should be filled with something neutral (for example, sand) and only after that it should be collected.
Sodium Sulfite - Preservative
Where is this powder used? The substance has very useful chemical properties. Thanks to them, sodium sulfite is used, for example, in the food industry. Processed fruits and vegetables are stored longer without darkening. As a preservative, it is used in winemaking and in the manufacture of sweets, using it to make long-stored dried fruits. At the same time, it should be noted that in Germany it is forbidden to use sodium sulfite in the processing of meat, since it masks its stale color, which can lead to mass poisoning.
Other applications
In addition to food, the second main direction of use of this compound is textile, as well as pulp and paper production. Here the main quantities of sodium sulfite go. But it is used for water purification and leather dressing. It cleans trinitrotoluene, which is subsequently used in mining or for army purposes. Pharmaceuticals and medicine also do not neglect this substance. A solution of sodium sulfite is often needed here. The compound referred to here is also used in the production of non-ferrous metals and sodium thiosulfate, which doctors prescribe in cases of poisoning with derivatives of lead, mercury and arsenic.
Outdated direction
At the time of film cameras and film cameras, sodium sulfite was simply necessary for developing the films themselves, preventing the oxidation of solutions, and washing media (film or photo paper) from the fixative. Now, with the proliferation of digital counterparts, this use of this substance has remained mainly for amateurs who have preserved the old technique. Specialists-photographers of the old generation argue that when developing black and white films, it is sodium sulfite that makes it possible to achieve the most traced details in the shadows and significantly increases photosensitivity in case of unsuccessful negative contrast.
As you can see, this is a substance that is necessary in different areas of human life. And if some direction of its use becomes irrelevant, there is another, no less important.