Cyan poisoning: apricot kernels or hydrocyanic acid

Cyan poisoning or prussic acid poisoning occurs when inhaling a cyanogen compound or hydrogen cyanide. This is also known as hydrocyanic acid. Nowadays, the consumption of apricot kernels is becoming more and more popular. This drug is said to work against cancer and have other benefits. Apricot kernels contain a quantity of cyanide that, at high doses, leads to cyanogen poisoning with all its consequences.

What is cyanosis?

Cyan poisoning is poisoning with a cyan compound or dycian. A cyanide compound (cyanide) can consist of potassium cyanide, sodium cyanide, vinyl cyanide, calcium cyanide. Hydrocyanic acid or hydrogen cyanide in particular is poisonous. Cyan is mainly used in industry, in the production of plastics, precious metal extraction, as weed control, pharmaceutical products, resins and as a solvent. A small amount of cyan is also found in stone fruits such as almonds, cherries, apricots, plums and peaches. Inhaling or ingesting cyanogen causes cyanosis that is almost always fatal. Cyan poisoning can occur in people who work with cyanide/cyanide, but also occurs in people who ingest cyan through food such as manioc root (cassava) or stone fruits.
Cyan poisoning is not the same as cyanosis. This involves blue discoloration of the skin due to too low oxygen levels in the blood. The cause for this is diverse.

Symptoms of poisoning

There is a difference between acute poisoning and poisoning due to long-term exposure or minor exposure to cyan. Eating stone fruits often causes a number of symptoms that are similar to cyanosis, but to a lesser extent. In acute poisoning, treatment is often too late. This last poisoning is fatal.
An acute poisoning can be recognized by shortness of breath, headache, confusion, nausea and vomiting. The skin turns blue to black. The patient falls into a coma and can die within seconds to minutes from asphyxiation. In case of slow poisoning due to long-term exposure, headaches, fatigue, general weakness, dizziness occur and the functioning of the thyroid gland may be affected. Although this form of poisoning is not immediately fatal, in the long run it can cause so much damage that unconsciousness or coma occurs. We are then talking about an increasing amount of cyan inhalation or ingestion through the stomach. The breath of patients who have been poisoned smells like bitter almonds, but this can be avoided.
Inhaling hydrocyanic acid (hydrogen cyanide or hydrogen cyanide) is immediately fatal when more than 300 mg/m3 is inhaled. In half of these, death occurs within 30 minutes.
The fatal thing about cyanide poisoning is the inactivation of the hemoglobin in the blood. Hemoglobin ensures the transport of oxygen and carbon dioxide in the blood. When the poison makes the hemoglobin inactive, oxygen is no longer transported. The tissues die very quickly, causing suffocation. Hemoglobin gives the red color to the blood. When hemoglobin becomes inactive, the red appearance under the skin disappears and a blue to blue-black discoloration occurs.

Almonds, cherries and other stone fruits are poisonous

Be careful when eating the seeds of stone fruits such as almonds, apricots and cherries. These contain a small amount of cyan. Although eating these kernels is not fatal, it does cause nervous system diseases. Often no direct link is made between the disease and eating the seeds. Apricot kernels are sometimes recommended as a remedy against cancer. Research into this was previously done, but because the kernels were far too poisonous, this research was stopped. Yet there are still quacks who sell apricot kernels as a miracle cure for cancer. After a number of months the cancer has not reduced, but the amount of cyanide in the blood has increased. In the past, fatal amounts of cyanide (after using apricot kernels) were sometimes found in the blood.


In the case of long-term poisoning, the diagnosis will be made on the basis of the symptoms. People who come into contact with cyanide as part of their profession must be aware of cyanosis and report this to the doctor if they have any complaints. Avoiding the workplace is important. The labor inspectorate checks whether there is actually a dangerous working environment. Eating stone fruits can also cause cyanide poisoning. We often see this in horses, but people are also sensitive to it when the seeds are eaten in large quantities. The doctor can make the diagnosis based on the complaints. Antidotes are administered to ensure that cyan is bound. Other agents ensure that the hemoglobin is not made inactive. A well-known antidote is DMAP. In addition, oxygen will be administered. In case of acute poisoning, rapid treatment is necessary. However, with a large dose of cyanuric acid, rescue is often no longer possible as death follows immediately.

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