Plasma balls are novelty devices that use principles of electricity and physics to create a mesmerizing visual display. This glass sphere contains a mixture of noble gases, such as neon and argon, surrounding a high-frequency, high-voltage electrode. While these lamps deal with high voltage, fatal electrocution from a standard, properly functioning plasma ball is extremely rare and highly unlikely.
The Science of Plasma Balls
A plasma ball operates by generating a powerful electric field from a central electrode, which is essentially a miniature Tesla coil. This electrode is connected to a circuit that produces a high-frequency alternating current in the range of 35 kilohertz (kHz) and a potential difference between 2,000 and 5,000 volts. The energy is transmitted into the surrounding glass sphere, which is filled with low-pressure inert gases.
The high-frequency, high-voltage field provides enough energy to strip electrons from the gas atoms, turning the gas into plasma, which is considered the fourth state of matter. These visible streamers, or plasma filaments, are the paths of ionized gas and electrons moving from the central electrode toward the outer glass insulator. The different colors are a result of the specific noble gases used, such as neon producing a reddish-orange hue.
Assessing the Risk of Electrocution
The primary reason a plasma ball is safe to touch, despite its high voltage, lies in the relationship between voltage, current, and frequency. Electrical lethality is primarily determined by the current flowing through the body, not the voltage alone. While the plasma ball operates at several thousand volts, the current it produces is extremely low, typically less than one milliampere.
For comparison, a current of just 10 to 20 milliamperes is required to cause muscle paralysis and difficulty breathing. The current is a high-frequency alternating current, which tends to flow over the surface of conductive materials, including human skin (the skin effect). This surface path prevents the current from penetrating deep into the body where it could interfere with the heart’s electrical rhythm. The combination of very low current and high frequency mitigates the risk of a severe electric shock.
Common Hazards Beyond Electric Shock
While the risk of a life-threatening shock is negligible, plasma balls pose several minor hazards. The most common experience is a mild static shock or a slight surface burn when touching the glass, especially if a metal object like a ring is placed on the surface. When a conductive object contacts the glass, it concentrates the electrical discharge, causing a sudden, uncomfortable jolt.
Plasma balls emit a strong radio frequency (RF) electromagnetic field that can interfere with sensitive electronic devices. This field may disrupt the operation of nearby laptops, cell phone touchpads, or radio equipment.
Of greater concern, people with implanted medical devices, such as pacemakers or hearing aids, should maintain a distance. The electromagnetic radiation can potentially disrupt the device’s function. Additionally, the electrical discharge near the glass surface can produce trace amounts of ozone, which is noticeable as a distinct smell and is a minor respiratory irritant.
Using Plasma Balls Safely
To ensure safe operation, always handle a plasma ball with basic electrical safety in mind. Avoid touching the glass for extended periods, as capacitive coupling can cause the glass to become warm to the touch. This may lead to minor thermal discomfort.
Keep the device at least four feet away from sensitive electronics, including computers, Wi-Fi routers, and medical equipment. Never place metal or conductive materials directly on the glass surface while operating, as this concentrates the discharge and increases static shock intensity. Always unplug the unit before cleaning, moving, or performing maintenance to ensure the internal circuitry is de-energized.