Technical Post: A Flavor Expert Talks About the Harm of E-Cigarettes

There are three main problems facing e-cigarettes at present: one is the problem of harm; the other is the problem of attracting minors to smoke; and the third is the problem of related conflicts of interest.

The problem is in front of us, and the key is how to solve it.

As a practitioner, I can only give some suggestions from the areas I understand, especially regarding the first hazard. Therefore, this article will discuss the first point, and everyone is welcome to discuss it together. Second and third points will be discussed with you in subsequent articles.

How harmful is e-cigarettes?

It is difficult to directly say a number for this kind of degree problem. The harm itself is difficult to quantify with numbers, so we can only make comparisons.

In the environment in which we live, it can be said that everything has the possibility of harm, and there is no absolutely safe environment.

Compared with the air in the smog days in Beijing, the air in the fresh mountain roads is also air. It goes without saying which one is more harmful.

If you eat greasy and high-sugar food every meal, compared with light and low-fat food every meal, the former will definitely be more harmful.

When used when sick, there are traditional Chinese medicines with complex ingredients and doubtful side effects, as well as clinical western medicines with strict ingredients and obvious effects. It is also clear.

If you don't have to breathe, you won't inhale smog. If you don't have to eat, you won't consume too much oil sugar. If you don't get sick, you won't have to worry about which medicine to use.

But we must breathe, we must eat, and we will definitely get sick. Then we have a choice. We will naturally pursue good luck and avoid evil and choose the party that is relatively less harmful. If you don't smoke or smoke, nothing will happen.

But there are many smokers who can't quit, so why not give them more choices?

When it comes to the harm of e-cigarettes, there are rumors that they are more harmful than real cigarettes, while some people say they are less harmful than real cigarettes. The United Kingdom has included e-cigarettes in medical insurance, and experts say that e-cigarettes are 95% less harmful than real cigarettes. The so-called e-cigarettes have occurred in the United States. Death case, but recently released relevant clarifications.

So what is truth and what is a lie?

Domestic e-cigarettes do lack authoritative laboratory reports at present, but there is never a shortage of people who don't understand them but want to hear and alarmist rumors. Independent thinking ability is very important, but few people have it.

What I wrote today may not be complete, but it was summarized through independent thinking, and I can confidently say that it will be more professional than those who don't understand and pretend to understand.

Before continuing to discuss the dangers of e-cigarettes, let's talk about how e-cigarettes work.

The formation of smoke first occurs when cigarette oil is vaporized through heating wires, and then condensed and liquefied to form small liquid particles (also known as aerosols). This is the process by which e-cigarettes generate fog. This process is the physical change of smoke oil-vaporization-liquefaction-liquid aerosol (fog). Of course, chemical reactions will inevitably occur in this process, because there is mixture and heating in the process.

For example, if you use it quickly, you will have a very clear intuitive feeling. That's right, the principle of e-cigarette atomization is very similar to putting it into water to boil water if it heats quickly. If it heats quickly, it is equivalent to heating wire. Water is equivalent to tobacco oil. However, in order to quickly atomize the smoke liquid, the heating wire is heated by an oil guide (cotton or porous ceramic) to instantly atomize the smoke liquid, so that the user will not directly inhale the smoke liquid.
 
After understanding how e-cigarettes work, let's continue to talk about hazards.

Assuming that e-cigarettes only work in a physical process, which is to completely atomize the tobacco oil into liquid aerosol, then the harm comes from the composition of the tobacco oil.

This is an ideal situation, but in fact, during the atomization process, chemical reactions will occur more or less, so we can divide the harm caused by e-cigarettes into two parts: 1. The tobacco oil itself contains harmful ingredients;2. Hazardous substances produced by heating during the atomization process of tobacco oil.

Let's first analyze Part 1, the harmful components of tobacco oil.

Here, we need to popularize the knowledge of tobacco oil to everyone. Simply put, tobacco oil is a mixture of PG (propylene glycol), VG (glycerin), nicotine, flavors and fragrances. Basically, all tobacco oil cannot be separated from these ingredients. If nicotine is not added, it is commonly known as 0mg of tobacco oil. PG is also propylene glycol. The toxicity and irritation are very small. So far, no case of e-cigarettes being harmful due to this ingredient has been found, but when added to food and drinks, the dose is too high at one time, There is a risk of causing fatal drowsiness and kidney disorders, and the amount currently used in e-cigarettes is far from reaching.# p#pagination title #e#

VG is glycerin, which is very common. It is used in most foods. You can learn about it through Baidu Encyclopedia.

Nicotine is nicotine, with a half-life of about 2 hours in the human body. The metabolite is cotinine, which will eventually be excreted in urine. There is currently no evidence that nicotine has a direct carcinogenic effect, but studies have reported that nicotine and its metabolites will Increase the risk of coronary heart disease.

If only qualified PGVG nicotine is used to make tobacco oil, then the toxicity will not be significant in appropriate amounts. It is worth reminding that nicotine in cigarettes does not cause much harm. The real carcinogens are the tar and carbon monoxide in cigarettes.
 
The only variable in tobacco oil is flavor and fragrance. When this variable is added, many questions will arise.

Let me give you a piece of data first. The amount of flavor added in general beverages is 0.05% to 0.5%, while the amount of flavor added in e-cigarettes, especially small cigarettes, is generally 15% to 25%.

Seeing this comparison of data, many people must feel that e-cigarettes are more likely to be harmful than drinks.

But I have to give another piece of data. Although this data may not be accurate, within a logically reasonable range of use, it is deduced that a 500ml bottle of Sprite essence content is 1ml based on 0.2%. It can be finished in about an hour. If you can finish it in one breath. The essence content in a 1.5ml cigarette bomb is 0.3ml based on 20%. It can be smoked for about 2 days. If you can smoke it quickly, you can smoke it in one day. Moreover, general smoking should spit out 90% of the smoke.

After looking at the data, I believe many people will understand that if we look at it purely from the perspective of flavors, as long as ordinary food flavors are used to formulate e-cigarettes, the harm of tobacco oil should be less than the harm of beverages. If PGVG and nicotine are added, The harm is difficult to compare, but I believe many people will have their own opinions.

Let's analyze Part 2, Hazardous substances produced by heating during the atomization process of tobacco oil.

In the material world we exist, energy exchanges occur all the time, and the general form of expression of this energy exchange is chemical reactions. For tobacco oil, even if it is left at room temperature, chemical reactions continue to occur. Heating will only make its reaction more intense and the direction of the reaction will become more variable.

When it comes to heating and atomizing tobacco oil, let me give an example to compare cooking. The boiling point of edible oil is generally above 200℃, the boiling point of peanut oil and rapeseed oil is 335℃, and the boiling point of soybean oil is 230℃. The boiling point of each component in tobacco oil is PG 188.2 ℃, VG boiling point is 290.9℃, and nicotine is 247℃. The boiling point of general essence is 120 - 180℃. The boiling point of general tobacco oil with a ratio of 50%/50% PGVG is about 250℃.

Through these data, we can imagine putting oil into the pan and heating it, and then adding various seasonings, soy sauce and food, especially when fried chicken. This must be fried under boiling conditions. The temperature should be higher than that of e-cigarettes. The pan is equivalent to heating wires, and the things in the pan are equivalent to tobacco oil. Personally, I think it is very vivid, so many experts in nutrition and health call for eating less fried food because it is harmful. This is a fact. But have we put an end to fried food?
 
Some people may say that flavors and spices are definitely more harmful than natural spices. First of all, I want you to understand the fact that most food or daily necessities in the world we live in are simulated with flavors and spices. First of all, flavors and spices are not necessarily all chemically synthesized, and there are also naturally extracted or natural equivalent flavors and spices. Secondly, the chemical composition of so-called natural spices is more complex and uncontrollable, while the synthetic ones are relatively pure. Just like the difference between traditional Chinese medicine and western medicine, it is difficult to draw a conclusion on which is more harmful. If you need to know more about nature and synthesis, you are welcome to come and discuss with me.

Now that we have a general understanding of the harmful components in tobacco oil and the final smoke produced, the following is the issue of absorption and metabolism in biology. I am not studying chemistry, nor am I studying biology. I can only analyze it through my own understanding of chemical biology, which may be right or wrong, for reference only.

Many people compare e-cigarettes with drinks, but there is a big difference between the two. Drinks are water as a carrier and carry aroma and taste substances, which are absorbed through the mouth and the intestines. E-cigarettes are PGVG as a carrier and carry aroma substances and nicotine. After atomization, they are absorbed from the mouth and into the lungs. Those who have studied biology should know that the human body is divided into internal environment and external environment. The digestive tract actually belongs to the external environment of the human body and has not really reached the internal environment such as blood cells.# p#pagination title #e#

When substances enter the digestive tract, substances only stay in the external environment of the human body. Macromolecule substances are decomposed into small molecule substances by various enzymes secreted by the digestive tract before entering the cell membrane and being absorbed into the blood. Of course, small molecule substances will be directly absorbed, such as water, inorganic salts, glucose, amino acids, and some simple organic compounds. Oils, proteins, etc. must be hydrolyzed by corresponding enzymes before being absorbed.

However, our lungs do not have the function of secreting digestive enzymes like the digestive tract. What the lungs absorb is generally substances in the air, such as oxygen, water vapor, etc. Many people understand the harm of dust. Dust belongs to the lungs. Substances that cannot be metabolized and absorbed will only adhere to lung cells after reaching the lungs with the air, which will cause problems in the lungs in the long run.

Then the question arises. What are the so-called e-cigarette deaths in the United States?

First of all, e-cigarettes have a history of more than ten years in the United States. There has never been a large-scale e-cigarette death outbreak like today. Why is it only happening now? I haven't heard of it before this year? The only reason that can be thought of is that they have added something that shouldn't have been added before, and this substance is vitamin E acetate.

Vitamin E acetate is a substance C31H52O3 with a molecular weight of 472. This substance itself is eaten as a health care product. It is beneficial to the human body. It enters the digestive tract and is absorbed by the intestines into nutrients to participate in human metabolism. However, it cannot be absorbed by the lungs and then accumulates in the lungs, eventually leading to lung disease.

Regarding why vitamin E acetate is used in so-called e-cigarettes, we have to talk about cannabis oil.

In places where cannabis oil was legal in the United States, they were very simple at first. They directly added the cannabis oil extracted from growing cannabis to e-cigarettes for aerosol inhalation. At that time, no one died from smoking cannabis, but because the cannabis oil was too expensive and the cost was too high. During the competition, black merchants began to use tricks. They used coconut oil to dilute the cannabis oil, which reduced a lot of costs. However, users are not fools. Coconut oil is generally colorless, transparent and relatively thin oil above 30 degrees Celsius. Good hemp oil is a golden yellow thick liquid. When the two are mixed, the color of the hemp oil becomes lighter and thinner.

Many users judge the quality of cannabis oil by its viscosity and color, but cannabis oil diluted with coconut oil has not had a significant impact on the human body.

But then they found a cannabis oil thinner beeswax that could perfectly replace coconut oil. The beeswax over there is vitamin E acetate.

Vitamin E acetate has three advantages over coconut oil. One is solubility. Cannabis oil is very soluble in vitamin E acetate. The other is color. Vitamin E acetate is also golden yellow. The third is viscosity. Vitamin E acetate is very viscous. High; and it is also a health care product, so there are cases of large-scale lung disease outbreaks and deaths.

There are actually two reasons why cannabis oil containing vitamin E acetate kills death:

1. Contains vitamin E acetate, a macromolecular substance that is difficult to absorb in the lungs.

2. Generally, some people who smoke marijuana have a habit of holding a puff means that the smoke they smoke is held in their lungs and not spit it out. That way, the feeling will be obvious.

On the one hand, e-cigarettes do not contain vitamin E acetate, because vitamin E acetate cannot be added to ordinary e-cigarette smoke oil because it is oil-soluble and insoluble in PGVG. On the other hand, people who smoke e-cigarettes are generally like smoking. The habit is the same as smoking, and you spit it out after passing through your lungs.

In fact, if you think carefully, you can find the reason. Why is there no case of e-cigarettes directly causing lung disease in China? Not only does it not exist in China, but there are no cases of e-cigarettes deaths in most areas where marijuana is not legal. However, many people attribute all the responsibility for deaths caused by smoking illegal marijuana to e-cigarettes. E-cigarettes were not invented to smoke marijuana in the beginning, but to provide more options. I hope that ignorant media or some people will not jump to conclusions before they fully understand the truth.

Through the death of vitamin E acetate, what we have to think about is what kind of substance is safe during the aerosol inhalation process, rather than blindly accusing e-cigarettes of being harmful. If compared with air (excluding nearby air and air with excessive PM2.5), it is harmful, but it is still far less harmful than other products.
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To analyze what substances cannot be added to e-cigarettes, there are two points: #p#pagination title #e#

1. Substances that cannot be absorbed by the lungs after atomization;

2. The substance itself can be absorbed, but it is harmful to the body after absorption.

First of all, if the flavors and fragrances generally used for consumption are absorbed, the harm should be within the range of the human body. Secondly, it is necessary to consider whether the flavors and fragrances used for consumption can be absorbed by the lungs after being atomized. I am not a biology major. I only know some basic biological theories. If there is any misunderstanding, I hope the god of biology can correct it.

Generally, small molecules can directly pass through the cell membrane and enter the interior of the cell. In theory, the smaller the molecule, the easier it is to enter. The larger the molecule, the more difficult it is to pass through the cell membrane. If it is large to a certain extent, it is impossible to pass through at all, so it can only stay on the surface or In the intercellular space, the molecular weight of general aroma substances is 29 - 300. Macromolecules are difficult to volatilize, so there is basically no aroma, such as the oils we usually use (Long-chain fatty acid glycerides), protein, starch (polysaccharides), and flavor monomers commonly used in food flavors have a molecular weight of no more than 200, which is much smaller than the molecular weight of vitamin E acetate of 472. As long as cigarette oil manufacturers do not add illegal raw materials, or when adding certain special raw materials, especially raw materials with relatively large molecular weights, there will be no major health hazards if clinical pharmacology determines that there is nothing wrong.

What has been analyzed above is just my personal opinion. This is just an understanding within the scope of what I have learned so far. Maybe in the process of accumulating knowledge in the future, I will find that it is wrong or still correct. I don't force everyone to believe what I said, just for everyone to refer to.
 
In general, any new thing has certain risks, but we must rationally analyze its advantages and disadvantages, give full play to its advantages and reduce the disadvantages, rather than resisting and suppressing it. Isn't this the so-called development?