Yes, welding can cause a burn that is physiologically identical to a severe sunburn, a condition commonly referred to as “arc burn” or “welder’s burn.” This acute injury results from intense exposure to ultraviolet (UV) radiation emitted by the electric arc, a hazard that affects both the skin and the eyes. The radiation produced is significantly more concentrated than sunlight, meaning unprotected skin can sustain damage in a matter of minutes.
The Source of the Danger UV Radiation from Welding Arcs
Arc welding relies on generating extremely high temperatures, often exceeding 5,000 degrees Celsius, which is hotter than the surface of the sun. This intense heat vaporizes metal and gas, creating a superheated channel of ionized gas known as plasma. This plasma is the source of a broad spectrum of electromagnetic radiation, including visible light, infrared (IR) radiation, and UV radiation.
The UV portion of this radiation is categorized into three types: UVA, UVB, and UVC. While the Earth’s atmosphere naturally filters out most solar UVC, the welding arc produces this short-wavelength, high-energy radiation in high concentration, making it particularly damaging. The total UV output is influenced by factors like the welding current and the specific welding process being used, with higher currents emitting greater radiation.
Understanding Arc Sunburn Skin Effects
The acute skin injury from welding is a form of photodermatitis. When unprotected skin is exposed to the intense UV radiation from the arc, the radiation damages the DNA within skin cells, or keratinocytes, triggering an inflammatory response. This damage results in what feels and looks like a severe sunburn, but the onset is much quicker due to the arc’s concentrated energy.
Symptoms of arc sunburn begin with noticeable redness and irritation in the exposed areas, which can progress to significant pain and tenderness. In more severe cases of overexposure, the skin may develop blistering, indicating a second-degree burn, followed by peeling days later as the damaged outer layers of skin shed. Even brief exposure to the arc light, especially when wearing thin clothing, can allow enough UV radiation to pass through and cause a burn beneath the fabric. This skin damage is not limited to direct exposure, as UV rays can also reflect off nearby metal surfaces and walls, causing burns on areas facing away from the arc.
Essential Protective Measures
Preventing arc sunburn and other radiation injuries depends on establishing a complete barrier between the body and the arc’s emission. The primary defense is wearing proper Personal Protective Equipment (PPE) that covers all skin surfaces. This includes flame-resistant, long-sleeved clothing and trousers made of thick, opaque material, as thin cotton may not fully block the intense UV rays.
Specialized welding gloves are necessary to protect the hands and forearms, as even a small gap between a sleeve and a glove can allow damaging exposure. A welding helmet or hand shield with the correct filter lens shade is mandatory to protect the face and eyes from the light’s intensity. The correct shade number for the helmet’s filter varies by the welding process and current used, typically ranging from #10 to #12 for common arc welding. Beyond personal gear, environmental controls like using welding screens or curtains can help contain the arc and prevent stray radiation from affecting bystanders.
The Related Risk of Flash Burn
The most common acute injury from the welding arc is a distinct condition affecting the eyes, known as photokeratitis or “welder’s flash.” This occurs when the UV radiation causes a burn on the cornea, the transparent outer layer of the eye, and the conjunctiva. The symptoms of this injury are often delayed, appearing several hours after exposure, making it difficult to immediately link the pain to the arc.
A flash burn causes a sensation described as having sand or grit in the eyes, accompanied by severe pain, excessive tearing, and sensitivity to light. Even an exposure lasting only a few seconds can be sufficient to cause this painful injury. Although the effects are temporary, it is a serious injury that requires immediate attention and should be treated as a medical concern.