Often an electric shock occurs due to the fact that the rules for working with high voltage are violated or the person does not know how to properly handle electrical appliances. In any case, the main reason is human carelessness.
What danger is a person with high voltage?
Even the smallest impact on the human body of an electric current can cause damage. It is necessary to take into account not only the fact of what will be the power of electric shock, but also how much it will affect the body. Dangerous stress for a person can even be minimal, since much more depends on the body itself. The current cannot be seen with your own eyes, determined by sound or smell, the effect begins when a person comes into contact with it.
How can current affect the human body?
An electric current can instantly spread through contact throughout the body. In order for it to pass through the body, it needs a place of "entry", and then the current, passing through the whole organism, has an irritating effect on it. For example, the effect of current on the human body is divided into several types:
- Thermal when a burn occurs.
- Mechanical when soft tissue breaks.
- Chemical is directly electrolysis itself.
Due to electric shock, a person may involuntarily contract muscles, paralyze breathing and stop the heart.
What voltage is considered dangerous to humans?
If a person is in a dry room, then for him a dangerous voltage, which turns out to be over 36 volts. Death can occur when a current shock of 0.1 amperes occurs. A current of 0.05 amperes is also life threatening. The fact is that with this amperage, convulsions occur that prevent a person from moving away from the source of the lesion.
If we are talking about static electricity, then such electricity is not dangerous to human life. The maximum that the human body can feel from the impact of a spark discharge is an injection. Great danger to human life is an alternating current. Hazardous voltage for humans - over 50 V, and under adverse conditions (humidity, for example) - over 12 V. Hazardous current - 50 mA. It is the current of this force that can cause damage, and its effect on the human body within 5 s can become fatal.
Factors that affect the body during electric shock
It should be taken into account not only the strength of the electric shock, but also what path it will take through the body. It is worth remembering that the longer the path of the current through the human body, the harder the consequences. As we have said, it is considered life-threatening alternating current, direct current is not so damaging to the human body. There are a number of additional factors that can increase the risk:
- Great amperage.
- Passing it through the body. It should be noted that different tissues of the body have different abilities for resistance, the current passes in most cases precisely through the blood vessels. The worst thing is when the current path runs along the entire body, for example, this can happen if the arm - legs are involved, then the current can pass through the heart, spinal cord or brain. But sometimes a fatal outcome can occur with the passage of the arm-to-arm current, it all depends on how big the dangerous voltage was.
- Exposure time. The time interval allowed for current exposure must not exceed 2 seconds.
- Conductivity.
- The area where electric shock occurs.
It is impossible to calculate exactly how the current will affect the body. An important role is played by the attention of a person, therefore, in hazardous places, it is necessary to provide for a safety sign with a special sign, which is called a “high voltage” sign.
What role does body resistance play?
The resistance of the body depends on the condition of its skin, such factors can exert their influence:
- What condition is the skin of a person, for example, it can be clean, can be dirty, wet, damaged.
- What was the area of contact of the current with the skin.
- The magnitude of the applied voltage.
- What frequency current passed through the body.
- The general condition of the human nervous system.
If the skin has been scratched or has abrasions on it, then dangerous stress can be minimal in order for death to occur, as the resistance of the body decreases. The ability to resist in a person who has a sweaty or dirty hand is lost. For example, a voltage of 30 volts with dry hands does not cause severe pain, and if you touch it with a wet hand, then the person will not be able to unclench his fingers and will feel severe pain. In such cases, it is customary to say that a breakdown of skin resistance has occurred.
The skin resistance may decrease even when a low voltage is applied, it is 20-40 volts.
What voltage is considered acceptable?
Statistics indicate that most injuries due to electricity occur as a result of touching bare wires. There are three safe voltages:
- In a room where there is no increased danger, 65 volts are allowed.
- In a room where there is danger, 36 volts.
- In a room with increased danger - 12 volts.
In the premises of the second and third type, the sign "high voltage" must be present, which will warn of danger. Often there is a defeat for employees who, by the nature of their employment, are required to work with voltages up to 1000 V, but neglect safety measures and do not use protective equipment.
The answer to the question of what voltage is considered dangerous can be quite simple: any electric shock can cause damage, but the most dangerous voltage is 60 V, when respiratory paralysis and cardiac arrest can occur. But this may not happen if you carefully treat everything that surrounds a person and at least somehow relates to electricity. Personnel who work with high voltage and electric current should always be aware of safety rules and be on high alert.
So, from this article you found out what stress is life threatening. We hope you find this information useful.