First, the definition of poison, under the condition of daily contact, small doses of chemical substances can interact with organisms chemically or physico-chemically, leading to the damage of metabolism, function and morphological structure of tissues and cells in the body.
1. In medicine, it refers to substances formed in organisms (including animals, plants, bacteria and fungi, etc.). Substances that can harm other organisms are called biotoxins.
2. Synthetic chemical poisons.
These two substances belong to the category of big poison. There is no absolute boundary between poison and non-poison.
There is a famous saying: "All substances are poisons, nothing is not poisons, the only difference is their dosage".
In a sense, there are no absolutely toxic or non-toxic substances in nature, such as arsenic, mercury compounds and snake venom. As we all know, poison can be used as a clinical drug to treat some diseases if it is used below the toxic dose. However, if the oxygen we rely on enters the body at a higher concentration than normal, oxygen poisoning will also occur.
Second, the ability of poison to cause damage to the body is called toxicity.
What we usually see as "highly toxic" and "low toxic" actually refers to the toxicity of poisons. According to the WHO acute toxicity classification standard, the toxicity classification of poisons is as follows:
1, highly toxic: toxicity level 5; Lethal dose for adults, less than 0.05g/kg body weight; Total lethal dose of 60 kg adults, 0.1g.
2. High toxicity: the toxicity grade is Grade 4; Adult lethal dose, 0.05 ~ 0.5g/kg body weight; 60 kg adult lethal total, 3 grams.
3. Moderate toxicity: toxicity level 3; Adult lethal dose, 0.5 ~ 5g/kg body weight; The total lethal dose is 60 kg for adults and 30 g for adults.
4. Low toxicity: toxicity grade 2; Adult lethal dose, 5 ~ 1.5g/kg body weight; The total lethal dose is 60 kilograms for adults, 250 grams.
5. Mild toxicity: the toxicity grade is1; Lethal dose for adults, greater than 15g/kg body weight; The total lethal dose of 60 kg adults is greater than 1000 g.
Therefore, whether food is toxic or not depends mainly on the amount of toxins and poisons in it, which requires advanced instruments for accurate detection. Even if the amount is detected, we don't know his ability to harm individuals, because everyone's physique is different and their resistance is different.