Several people died due to dry ice in the pool. It’s on every meat and fish counter—is it really that dangerous?!

Three people died while celebrating the birthday of blogger Ekaterina Didenko in a Moscow bathhouse. The cause of the tragedy was that about 30 kilograms of dry ice were poured into a small pool. Once in the water, it quickly turned into carbon dioxide and displaced oxygen from the small space. Two of those who jumped into the pool suffocated and died on the spot, several more people were taken to the hospital. Didenko's husband, Valentin, later died in intensive care.

Dry ice is carbon dioxide, also known as carbon dioxide (CO₂), in solid form. Scientists received its first samples back in the 19th century, and began to actively use it already in the 20th century. Dry ice is produced this way: carbon dioxide is cooled to a solid state, after which it becomes similar to loose snow, and then pressed under pressure to obtain granules or blocks of a denser consistency. The temperature of dry ice is about -79 °C.

Most often - for freezing products, as well as for their transportation and storage. It was for this purpose that dry ice began to be used in the United States back in the 1920s. When food is quickly frozen, it retains more beneficial properties because it occurs at temperatures much lower than what is needed to freeze water. Thus, the water does not have time to form large ice crystals, which destroy the cells and fibers of the food.

Dry ice is also used when serving food in restaurants or during performances to create a fog effect. If you put dry ice in a glass, the liquid in it will begin to bubble, as if boiling, and dense white smoke will descend along the walls. When the carbon dioxide has completely evaporated, bubbles will appear in the drink and it will be ready to drink. It is with the help of CO₂ that all carbonated drinks and lemonades are produced.

Not really. The normal concentration of carbon dioxide is considered to be 0.04% - this is how much CO₂ is contained in the Earth's atmosphere. Indoors its content can increase to 0.06%. But if there is noticeably more carbon dioxide in the air, people present in the room may develop carbon dioxide intoxication, or hypercapnia. Carbon dioxide accumulates in the blood and tissues, and the person experiences headaches, nausea and suffocation. If oxygen is not provided to the lungs in time, a person with CO₂ poisoning may lose consciousness and die.

During the evaporation of a large mass of dry ice, the concentration of carbon dioxide in the room increases sharply, but those present may not immediately feel this. That is why all instructions for dry ice recommend using it outdoors or in well-ventilated areas.

Yes, that's what happened. The footage that Didenko’s guests recorded seconds before the tragedy shows that dense white smoke formed in a small pool where dry ice was thrown. People who immediately dived into the water found themselves in a dense cloud of carbon dioxide, which instantly displaced oxygen. As Valentin Vlasov, scientific director of the Institute of Chemical Biology and Fundamental Medicine of the Siberian Branch of the Russian Academy of Sciences, said , their heads actually ended up in a layer of carbon dioxide above the water, but they did not immediately understand what was happening, so they began to lose consciousness. You can faint and choke in such a situation after just a few breaths.

No, there is no such ban. There are dozens of videos online of people throwing roughly the same amount of ice into a pool and even swimming in it afterward. But they do this in open pools, where the likelihood of suffocation is extremely low. This is exactly what, judging by Valentin Didenko’s correspondence posted online, the dry ice manufacturer warned the organizers of the holiday in the bathhouse. Moreover, when working with dry ice, even in open areas, additional safety measures must be observed. For example, you can only touch it with gloves, otherwise there is a high probability of getting serious frostbite. For the same reason, dry ice should not come into contact with the eyes and open areas of the body: when working with it, it is recommended to wear glasses, closed clothing and shoes. Solid carbon dioxide should not be swallowed - if you want to drink a drink with dry ice in it, you must wait until it is completely dissolved.

Unfortunately, this happens. Most often, people die from carbon dioxide poisoning in poorly ventilated basements and cellars, especially if root vegetables such as potatoes or carrots are stored there. When they rot in a closed, unventilated room, thiols, carbon dioxide and methane accumulate. A person going down to the basement may not notice that carbon dioxide has practically replaced the air in the room, quickly lose consciousness and die.

You can also be poisoned by carbon dioxide when descending into a well, where this gas also accumulates. Therefore, before descending, it is usually advised to lower the candle down: if it goes out, it means that it does not have enough oxygen to burn and it is dangerous to be below.

The heroine of Emile Zola's novel The Misdemeanor of Abbe Mouret committed suicide by locking herself in a room full of flowers that emit carbon dioxide. A similar rumor circulated about the death of Russian actress Vera Kholodnaya. According to one of the versions , which was voiced, including by her granddaughter, she could have suffocated from the smell of a huge bouquet of lilies. However, such cases are unlikely. This will require either a very small room or a huge number of flowers that would fill the room to the ceiling. Moreover, everything should happen at night, when plants do not produce oxygen during photosynthesis, but only absorb air and release carbon dioxide.

It's impossible to say for sure. There are places in nature where, due to certain conditions, carbon dioxide accumulates, despite a sufficient concentration of oxygen. For example, in the Dog Cave near Naples, carbon dioxide accumulates, which comes there from a fumarole - a volcanic fissure. But since CO₂ is heavier than air, it remains only in the deep parts of the cave at the very bottom. People of average height were not in danger in such parts of the cave, since they breathed air near the vaults. However, a dog that was closer to the ground could lose consciousness from carbon dioxide poisoning. It was this experience that was demonstrated by local guides who took tourists to the cave in the 19th century. The dog was later revived by being immersed in the cold water of the lake.

No, carbon monoxide and carbon dioxide are different substances. Carbon monoxide, also known as carbon monoxide (CO), is formed when materials containing carbon are burned and is considered very toxic - its concentration in the air can be much lower for poisoning than in the case of carbon dioxide. When carbon monoxide enters the human body, it affects hemoglobin and can quickly block the processes of oxygen transport throughout the body and cellular respiration. Most often, people die from carbon monoxide poisoning in locked garages with the car engine running or in a house with closed windows where the stove is not heated properly.

Yana Khlebnikova