Introduction:
We are facing a new type of waste from electronic cigarettes (e-cigs). With or without nicotine models, they are biohazard and electronic waste (e-waste). As of February 2023, more than 17,000 devices capable of nicotine release are legally marketable in Spain. This list is updated monthly. Many of them are fully disposable generating worrying volumes of e-waste. They should be treated as toxic waste because they are sources of contamination by batteries and metals such as aluminum, barium, cadmium, chromium, copper, iron, lead, nickel, silver, tin and zinc. Copper is a potentially cytotoxic metal. Other potentially toxic additional materials are nozzles, rubber stoppers and plastic capsules. This type of waste is capable of producing aggressive leachates that exceed US regulatory thresholds for hazardous waste designation by up to 10 times. We do not have complete records to know the volume of sales of such devices and how they are discarded. Our aim is to describe the elements that make up e-cigs even without nicotine, for a better understanding of its disposal.

Material and Methods:
We bought various disposable e-cigs with and without nicotine at online and physical stores in Barcelona, Spain. Then disassemble them and classify and weigh their compounds.

Results:
In all of them we found a large amount of waste. The commercial presentation is a cardboard box with striking colors and motifs. Inside we find an airtight plastic envelope that contains the device and silicone covers that close the air inlet and the suction nozzle. Its capacities range from 600 to 10,000 puffs. The basic structure of the device is a metal or plastic body, and its ends have plastic plugs, which functioned as a mouthpiece and air inlet. All studied devices have a 3.7V battery. with capacities from 500-550 mA/h. or more (in devices with a greater number of puffs, the battery can be recharged before completely disposing of the device). A plastic reservoir filled with 2ml. to 20ml. of liquid. In most of the devices, it is observed that the inhaled airflow comes into direct contact with the battery body and then reaches a resistive wire that, forming a spiral, heats up to vaporize the liquid content inside the reservoir. Another component present in all cases is a switch that controls the power supply to the coil. It is located near the air inlet, and is activated spontaneously by the user's inspiration.

Conclusions:
The disassembly of each unit studied required a lot of time. It can be very complex to separate and properly process its different components on a large scale. Although there is a Spanish regulation for the disposal of e-waste, in our opinion, the high volume of devices does not allow controlling the environmental risk, so we believe that it could be more beneficial to definitively prohibit their sale. We are very concerned about the “nicotine-free” devices. Most, if not all, are marketed with child-appealing colors, motifs, and flavors. In our opinion, even without addictive compounds, they could become a "normalizing" mechanism for future vaping and smoking. Especially in young people, it could facilitate acceptance behaviors of e-cigs with nicotine and even combustion cigarettes.