E-cigarettes are a new trend

E-cigarettes are composed of two parts: the main unit and the electronic atomizer. There is a battery inside the main unit, usually a lithium-ion polymer battery, and the electronic atomizer is where the electronic liquid is placed. The blending agents of e-liquids are mainly 1,2-propanediol and glycerin, some of which are added with nicotine and other flavors. There is an atomizing core inside the atomizer, which is used to heat the e-liquid into mist. However, the service life of the atomizing core is limited.

The host is divided into two mainstream styles, electronic and mechanical. Electronic mods usually have a short-circuit protection mechanism. If the atomizer is short-circuited, it will automatically fail to emit mist. The mechanical hosts operate entirely on electrical principles, and most of the explosions in these reports belong to this type of hosts. Explosions are usually caused by accidents such as a short circuit in the atomizer, mismatched batteries, or accidental triggering of continuous misting. However, because of the beautiful appearance of this model, many people collect it, and the special material or brand may be sold at a high price in the market.

There are two main types of atomizers, RDA drop oil repairable atomizer and RTA oil storage tank repairable atomizer. In other words, RDA e-juice tastes better, you can add as much as you need, and the storage space is usually larger, you can choose a variety of coils; RTA is more convenient to go out, the space in the warehouse is usually small, but it can be filled Continuous pumping after oil. Recently, some manufacturers have launched RDTA, some add oil storage tanks on the basis of RDA, and some strengthen the structure of RTA so that it is closer to the taste of RDA e-juice.

The atomizing core is usually composed of a coil (commonly used materials are nickel, titanium, stainless steel) and cotton. The cotton will absorb the e-liquid, and then turn on the electricity to heat the coil, turning the e-liquid into mist. Some atomizing cores can be replaced with coils or new cotton.

E-liquid components mainly include glycerin (VG), propylene glycol (PG) and spices. These materials are usually widely used in cosmetics and food, and can be bought in chemical stores. Therefore, the threshold for making e-liquid is very low. Most people can make their own e-liquid with different ingredients and proportions, and even sell it. These e-liquids are mainly used in open systems, and are products banned by the WHO. Because most of the e-liquids on the market are not clearly labeled, and the ingredients are not known, it is difficult to assess its impact and harm on the human body. A closed system cannot add components by itself, which is relatively safer.

Glycerin (VG) is a commonly used drug and food additive (usually used in making cakes, chocolates and other sweets), has no side effects on the human body, has no color and taste, is hygroscopic, but has a high viscosity, so it will slightly increase atomization Difficulty cleaning the device and reducing the speed of oil conduction of the core (relatively easy to dry burn/paste). VG can be directly extracted from vegetable oil, coconut oil and palm oil, heated to high temperature, and then purified by distillation. Therefore, legal e-cigarette liquids generally use USP food-grade vegetable glycerin with a purity of 99.7%, while the remaining 0.3% is water.

Propylene glycol (PG) is used to dilute the viscosity of VG. It has high hygroscopicity, slightly sweet taste, no color or taste, and its fluidity is similar to that of water. The US Food and Drug Administration (FDA) describes PG as "generally safe for humans" (ingestion only). It is a common drug and food additive. PG has good oil-conducting properties and produces a small amount of smoke and a throat sensation similar to smoking.

FDA research has confirmed that PG is a safe additive (ingestion only), although it is also one of the main components of antifreeze, commonly used in antifreeze and food and beverages with special requirements. Although PG is generally safe, a small number of people may have mild allergic reactions, such as sore throat, phlegm, dizziness, etc. However, these side effects are usually short-lived and not serious.

The FDA's statement is "Generally Recognized as Safe (GRAS)". This definition refers to the safety of ingestion. Other methods through inhalation, injection or topical use are not included in the scope of GRAS. Therefore, e-cigarettes include e-liquid The safety of the aerosol produced after nebulization is not guaranteed by the FDA [9].

In addition to the flavor of tobacco, e-liquid can also be made into different flavors with various natural edible flavors, such as mint, fruit, desserts, drinks, etc. Adding these flavors can make the taste better. Nicotine is an addictive substance, but e-cigarettes themselves do not add nicotine. Electronic cigarettes containing nicotine are called electronic nicotine delivery systems (ENDS), and those without nicotine are called electronic non-nicotine delivery systems (ENNDS) [11]. Although ENDS and ENNDS are similar in design, the application of the device fluid used for heating, operating temperature and performance are quite different. Compared with tobacco, the nicotine content of e-liquid can be controlled.

The WHO pointed out in the latest research report in May 2021 that in countries where e-cigarettes can be legally regulated, manufacturers or operators should clearly indicate the nicotine content. Although it is difficult to control the nicotine emission rate of electronic nicotine delivery systems (ENDS), before the regulatory measures take effect, he suggested that relevant authorities should require manufacturers to disclose detailed product information, including nicotine content, ingredients, production date, shelf life, etc. etc. [13].

Although e-cigarettes may be less harmful than traditional cigarettes, they still carry certain risks. For non-smokers, e-cigarettes can be a gateway for them to be exposed to nicotine and start smoking. For smokers, e-cigarettes can be used as a smoking cessation aid, but can also lead to their continued dependence on nicotine. Therefore, for adolescents and non-smokers, use of e-cigarettes should be cautious and avoid long-term use. When choosing to use e-cigarettes, it is best to choose products that are regulated and have legal certification, and follow the corresponding usage suggestions and precautions. In addition, people who have nicotine dependence problems or are allergic to e-cigarette ingredients are better off avoiding e-cigarettes. Before using e-cigarettes, it is best to consult a doctor or obtain relevant health information.