Is solder tin toxic by soldering iron? How to prevent effectively?

Most electronics engineers should have soldered the board with soldering iron, and is the solder tin poisonous?

1.Is solder tin with soldering iron poisonous?

Some internet users make complaints about the fact that he used solder tin all year round at PCB factory. He felt that he was beginning to feel uncomfortable, and his stomach was a little swell. Is it lead poisoning?


In fact, it also depends on whether the solder wire used for soldering with electric soldering iron is lead-free or not at work, and the blood lead needs to be checked regularly. If it does not exceed the standard, there will be no problem at all. Is the solder tin toxic?


Normally speaking, if protection and raw material procurement are carried out according to national standards, soldering tin will not cause major damage. Now basically lead-free products are used.


Lead is a toxic substance. Excessive absorption by human body will cause lead poisoning. Low dose intake may affect human intelligence, nervous system and reproductive system. The alloy of tin and lead is the commonly used solder. It has good metal conductivity and low melting point. Therefore, it has been used in welding technology for a long time. Its toxicity mainly comes from lead. Lead smoke produced by soldering tin can easily lead to lead poisoning.


Metal lead may produce lead compounds, which are all classified as dangerous substances. In the human body, lead will affect the central nervous system and kidney. The environmental toxicity of lead to some organisms has been generally confirmed. Blood lead concentration reached 10 μ G / dL or more will produce sensitive biochemical effects. If exposed for a long time, the blood lead concentration will exceed 60 ~ 70 μ G / dl will cause clinical lead poisoning.


Lead must be toxic. Let alone soldering tin has little impact on the body. Even ordinary metals will be poisoned if they are too much. When soldering tin, there will be smoke, which contains an element harmful to the body. When working, it’s best to wear a mask, but it will still have some impact. Of course, if you can use lead-free solder wire, it will be much safer than those with lead.


2、 Is lead-free solder toxic?


The material used for soldering tin with electric soldering iron is solder wire. Although its main component is tin, it also contains other metals. It is mainly divided into lead and lead-free (i.e. environmental protection type). With the introduction of EU ROHS standard, more and more PCB welding factories choose lead-free and environment-friendly. Lead solder wire is also slowly being replaced, which is not environmentally friendly and cannot be exported. Lead free solder paste, lead-free tin wire and lead-free tin bar are the main products in the market at present.


To put it simply: generally used soldering tin is toxic because of its low melting point, containing 60% lead and 40% tin. Most of the soldering tin on the market is hollow and contains rosin, so the gas you said is estimated to be volatilized when the rosin in the soldering tin melts during welding. The gas volatilized from rosin is also slightly toxic. This gas smells bad.




The main hazard factor of soldering tin is lead smoke. Even lead-free soldering tin contains a certain amount of lead. The limit of lead smoke in gbz2-2002 is very low and toxic, so it needs to be protected. Due to the damage of welding process to human body and environment, in Europe, the protection of welding workers and the protection of the environment have been enforced in the form of legislation. Welding without protective measures is not allowed. In ISO14000 standard, there are clear provisions on the treatment and protection of pollution generated in production links.


Tin contains lead. In the past, there was lead in the solder wire. Solder is classified as an occupational hazard post (in the national catalogue of occupational diseases); Now our general enterprises use lead-free solder wire. The main component is tin, and the center for Disease Control and prevention measures tin dioxide; It is not in the national occupational disease catalogue.


Generally speaking, lead smoke in lead-free process will not exceed the standard, but there are other hazards in soldering tin. For example, soldering flux (rosin substances) has certain hazards, which should be seen according to the specific situation. Employees can usually look at the identification and category of tin distributed, so that they can be well documented and require the enterprise to make rectification (they can give opinions to the internal trade union of the factory). If the tin contains lead, it must be harmful to your health. Over time, they accumulate in the body and cause great damage to the immune system of the nervous system.

Lead free solder wire is environmentally friendly, but lead-free solder wire is also harmful to human body. The low lead content of lead-free solder wire is not lead-free. Compared with lead-containing solder wire, lead-free solder wire has less pollution to the environment and human body than lead-containing solder wire. The gas generated during soldering is toxic, including rosin oil, zinc chloride and other gas vapors.

3、 How to prevent electric soldering iron and solder wire from being poisonous

First of all, PCB factories should use RoHS tin wire when soldering components with electric soldering iron, and do a good job of prevention: for example, wear gloves, masks or gas masks, pay attention to ventilation in the workplace, have a good exhaust system, pay attention to cleaning after work, and drink milk can also prevent lead toxicity in soldering tin.

1. To rest for a period of time: generally, you should rest for about 15 minutes for an hour to alleviate fatigue, because the resistance is the worst when you are tired.

2. Smoke less and drink more water, which can eliminate most of the harmful substances absorbed during the day.

3. Drink mung bean soup or honey water before going to bed, which can reduce fire and help your mood, and mung beans and honey can eliminate a large amount of lead and radiation absorbed.

4. Avoid radiation and try to avoid waiting for mobile phones.

5. You can brighten the soldering iron and try to use the PPD welding head. In this way, when the temperature is reached, you can use less welding oil and rosin to reduce the harm to your body,

6. When the soldering oil and tin smoke, try to brush the sky with your head to the side, and try to hold your breath when you brush the water.

7. Use less Tianna water, use more alcohol, and brush more with alcohol for a while. The effect is almost the same.

8. Wash your hands.

9. Take a bath before going to bed. Try to go to bed and get up early to ensure adequate sleep. As long as you sleep well, impurities can be basically discharged with your body.

10. Work with masks.

Post time: Apr-12-2022