When welding with an electric soldering iron, smoke is produced in contact with the solder. What is the reason? Is it harmful to the human body

When welding with electric iron, if heated with rosin, smoke will be produced. The smoke produced is harmful to the human body. Because the smoke produced by the soldering process contains lead, as we all know, lead is a heavy metal and is toxic, so long-term exposure is harmful to the human body. The best solution is to connect the exhaust air, like a range hood, to direct the gas to the outside. It is better to use adjustable constant-temperature soldering iron; When you do not need a soldering iron, keep a certain amount of tin on the tip of the iron, and do not clean the tip on the sponge and store it on the soldering iron rack; The sponge needs to keep a certain amount of water until the sponge is wet all day. When picking up the soldering iron to use, clean the tip. However, in the process of use, there is no need to take the soldering tip to the sponge to clean, just put the tin on the soldering tip into the tin set cardboard box, so that the temperature of the soldering tip will not drop rapidly, if the IC is difficult to extract tin, add some tin up (because the tin wire contains flux), you can easily extract more tin down. The soldering iron temperature between 340 and 380 degrees is normal, if some sensitive elements can only accept the welding temperature of 240 to 280 degrees; The hair of the soldering iron is black, which can not be treated with metal devices such as blades, but should be solved with rosin or tin wire; After use every day, first clean, then add enough tin, and then immediately cut off the power. Reference: Encyclopedia - Electric soldering iron