Possible adverse health effects include erythema (sunburn), photokeratitis (feeling of sand in the eyes), skin cancer, increased skin pigmentation (tanning), cataracts and retinal burns. Unfortunately, there are no immediate warning symptoms that indicate overexposure to UV radiation. Ultraviolet (UV) radiation is electromagnetic energy with a slightly shorter wavelength than that of visible light. UV energy stimulates the production of vitamin D in our body and is used to treat psoriasis, but it can also cause skin cancer, sunburn and cataracts.
For most people, the main source of UV exposure is the sun. Sun exposure is usually limited to the UV-A region, as the Earth's atmosphere protects us from the most damaging regions of UV-C and UV-B rays. Limiting exposure time and using sunscreen lotions are two simple and effective ways to control overexposure to UV radiation. Only artificial light sources emit radiant energy within the UV-C band.
Wavelengths lower than 180 nm (UV in vacuum) are of little practical biological importance, since they are easily absorbed by air. The effects of exposure to UV rays are not immediately felt; the user may not be aware of the danger until damage has occurred. Symptoms usually appear 4 to 24 hours after exposure. It's important to note that UV radiation is harmful to both the skin and the eyes. The eyes are very sensitive to UV radiation.
Long-term direct exposure to UV-B and UV-C light can cause serious effects, such as conjunctivitis and photokeratitis. Conjunctivitis is an inflammation of the membranes that line the inside of the eyelids and cover the cornea. Photokeratitis is manifested as an aversion to bright light. The severity of these conditions depends on the duration, intensity, and wavelength.
Symptoms may appear 6 to 12 hours after exposure and may disappear after 24 to 36 hours without permanent damage. Unlike the skin, the eyes do not develop a tolerance to repeated exposure to UV rays. The absorption of UV-A radiation in the lens of the eye can cause a progressive yellowing over time and may contribute to the formation of cataracts, causing partial or total loss of transparency. The extent of the damage caused by exposure to UV radiation depends on several factors.
It is commonly known that people with paler skin are more photosensitive than those with darker skin; however, prolonged exposure to artificial sources of UV rays can damage any type of skin. Certain medications, chemicals, and dietary and herbal agents can affect a person's sensitivity to UV rays. Skin conditions or eye infections can also cause increased photosensitivity, even in people who are not normally photosensitive. It's important to note that guidelines for using filters in protective equipment may not address these sensitivities, so additional precautions may need to be taken.
UV radiation is used in a wide variety of medical and industrial processes to kill bacteria or produce fluorescence; these include the photocuring of inks and plastics (UV-A and UV-B), photoresistant processes (all UV), solar simulation (all UV), cosmetic tanning (UV-A and UV-B) and dentistry (UV-A). UVR is also used in UV light boxes (transilluminators), germicidal lamps and UV cross-linkers. Other artificial UV sources include solid-state light sources, such as light-emitting diodes (LEDs) and lasers. In addition, UV radiation is a by-product of processes such as welding and plasma cutting.
Germicidal lamps are used in a variety of applications where disinfection is the primary concern, such as purifying air and water, protecting food and beverages, and sterilizing sensitive tools, such as medical instruments. They emit radiation almost exclusively in the UV-C range. The most effective wavelength is 253.7 nm, which defines the germicidal category. Germicidal light destroys the ability of bacteria, viruses and other pathogens to multiply by disabling their reproductive abilities.
Lamps that generate energy at wavelengths lower than 250 nm (particularly 185 nm) are very effective in producing ozone, which is necessary for certain applications to oxidize organic compounds. Germicidal lamps are commonly used in laminar airflow hoods or in biological safety cabinets. In some cases, germicidal lamps can be used in special ceiling luminaires to sterilize entire rooms; these lamps should be treated with extreme care. Safety tips for using germicidal lamps UV transilluminators or UV light boxes are used in biotechnology for the visualization of nucleic acids (DNA or RNA) after gel electrophoresis and ethidium bromide staining.
The samples are placed in the lighting window and illuminated with ultraviolet light. The devices operate in one of several wavelength bands, depending on the type of sample. The standard wavelength bands are 254 nm, 312 nm, and 365 nm. Most of these instruments are stationary, but some portable types carry the same risks as stationary models. Safety tips for using transilluminators and reticulators A solar simulator (also called artificial sun) is a device that provides lighting that is close to natural sunlight.
The goal of the solar simulator is to provide controllable laboratory conditions for testing solar cells, solar filters, plastics, and other materials and devices. The three main types of solar simulators are continuous, intermittent and pulsed, according to the use. The types of lamps used as light sources for solar simulators include the xenon arc, the metal halide arc, and LED lamps. Safety tips for using solar simulators Safety tips for using UV curing systems Plasma engravers are designed for deposition and etching processes on silicon wafers and other substrates.
Designed as modular systems, they use radio frequency (RF) and microwave energy to create plasma inside a process chamber. Plasma recorders pose several hazards, including hazardous process gases and chemicals. UV radiation is often a secondary hazard to plasma. UV light can also escape from other parts of the system (e.g., it is necessary to filter and protect carefully to avoid exposure to UV rays).
Camera viewpoints are considered to be a particular risk area. Some graphic windows protect against the emission of ultraviolet light and the emission of RF energy, and they incorporate an implosion protector. They are equipped with clear plastic UV filters, as well as a metal grid to protect them from RF radiation. Graphic windows are usually made of glass or quartz.
Make sure that these graphic windows are properly mounted and are not damaged. If a filter is not properly placed or if you are not sure if it is positioned correctly, contact the manufacturer for advice before using the equipment. The UV filter inside the window assembly is essential for operator safety. System safety devices are used to protect different functions, such as the activation of the radio frequency power supply and the activation of process gases.
Unfortunately, UV filters are not part of locking systems. A xenon arc lamp is a specialized type of gas discharge lamp that produces light by passing electricity through ionized xenon gas at high pressure. It produces a bright white light that closely mimics natural sunlight. Xenon arc lamps are used in movie projectors in cinemas, projectors and in industry and research to simulate sunlight.
Other applications include air pollution analysis, biochemical analysis, blood or urine testing, color detection, factory automation, gas analysis, precision photometry, semiconductor inspection, shape inspection and spectrophotometry. Tungsten halogen lamps are ideal light sources for spectrophotometers, as they provide wide-band spectral radiation ranging from UV to visible to infrared rays, up to 5 microns. They are excellent for brightfield examination, photomicrography and digital imaging of stained cells and tissues, as well as for numerous reflected light applications for industrial manufacturing and development. A mercury vapor lamp is a gas-discharge lamp that uses an electric arc through vaporized mercury to produce light.
Arc discharge is usually limited to a small fused quartz arc tube mounted inside a larger borosilicate glass bulb. Transparent mercury lamps produce white light with a bluish-green tint (the result of mercurial spectral lines combined). An LED lamp produces light in a single wavelength, without the need for a monochromator. Because the lifespan of LEDs is almost infinite and the light spectrum is stable, with little variation in bandwidth, LEDs are an attractive, low-cost solution for simple applications.
A deuterium arc lamp (or simply a deuterium lamp) is a low-pressure gas-discharge light source that is often used in spectroscopy when a continuous spectrum is needed in the UV region. Deuterium arc lamps emit in the UV region of 190 to 370 nm. Because the lamp operates at high temperatures, normal glass cases cannot be used as a housing. Instead, a fused quartz, UV glass, or magnesium fluoride enclosure is used, depending on the specific function of the lamp.
Safety tips for using portable UV sources Do not touch the lamp with bare skin. The skin oils from a hot lamp permanently etch quartz (devitrification) and cause local overheating. The build-up of tension leads to premature and catastrophic failure. Cleaning the lamp with alcohol before installing it is a useful precaution. Ozone is produced by the absorption of short-wavelength UV rays because of oxygen.
Ozone is a powerful oxidizing agent and can damage cells, especially in the lungs. Make sure there is adequate ventilation when using strong short-wavelength UV-B and UV-C sources. Phosgene forms when a chlorinated hydrocarbon or PVC solvent is exposed to UV radiation or intense heat. Even very small amounts of phosgene that come into contact with moisture in the lungs will produce hydrogen chloride and damage the lung tissue.
Be aware of the hazards associated with a particular artificial source of UV rays; if there are any questions or concerns regarding safety, contact the Non-Ionizing Radiation Program (NIR) contact point for advice. Control measures should be taken to limit eye and skin exposure and avoid cumulative exposure. The necessary precautions depend on the risk assessment. Whenever possible, control measures designed to eliminate the risk of exposure to UV rays at their source should be implemented, such as administrative and engineering controls and personal protective equipment (PPE).
A key element in achieving the objective of reducing exposure to UV rays is the training and awareness of workers. It's ideal to have the equipment located in a separate room, in an alcove, or in a low-traffic area of a laboratory. To help prevent exposure to other employees, avoid placing equipment in the immediate vicinity of desk areas or other equipment. The use of light-tight cabinets and cabinets is the preferred means of preventing exhibition.
When it is not possible to completely enclose the UV source, use screens, shields and barriers. Covers or partial cases should not be removed when the equipment is in use. If they are discolored, degraded, or damaged in any way, they must be replaced. Typical administrative controls include limiting access to UV sources, ensuring that staff are aware of potential hazards, and providing staff with safe training and work instructions.
Warning signs are necessary unless the UV radiation is completely closed and there is no risk of exposure during use and maintenance. When appropriate, warning signs should be used to indicate the presence of potential UV-related hazards, restrict access and select appropriate personal protective equipment. Below are some variations of the UV hazard warning sign. Based on the risk assessment, appropriate personal protective equipment may include goggles, face shields, gloves and laboratory gowns.
The XXZ87+U6D3D4 brand, for example, indicates that the glasses provide superior UV filtration and protection against the risks of splashes and dust. The “XX” is reserved for the manufacturer's name. Full face shields that absorb UV rays should be used in addition to eyeglasses or safety glasses (glasses may not provide sufficient facial protection). Serious skin burns can occur in a very short time, especially under the chin (which is often exposed).
Full face shields are the only adequate protection when working with UV light boxes for more than a few seconds. At a minimum, nitrile, latex, or dense-woven fabric gloves are recommended to protect against the significant amounts of UV-A and UV-B rays that can pass through the skin; these types of gloves have low UV transmission compared to vinyl gloves. Gloves must protect personnel from ultraviolet light, as well as from the danger of the activity being carried out. Personal protective equipment should be readily available and cleaned between users or assigned personally to each user. Eye and face protection should be inspected regularly or before each use for damage or defects such as cracks, cracks or discoloration, and replaced when necessary.
Keep in mind that personal protective equipment can serve several purposes, such as protecting against chemical splashes and UV rays. Many UV-generating devices have UV light bulbs that can be replaced. DO NOT dispose of UV bulbs in normal trash. The disposal of these bulbs must be done through Environment, Health and Safety (EHS) because the bulbs may contain mercury and are considered hazardous. They are subject to certain regulatory requirements for disposal.
Contact your waste generator for assistance. The signs and symptoms of accidental exposure include erythema of the skin (similar to a sunburn) and possible inflammation of the eye caused by injuries to the cornea. Never work in a biological safety cabinet while the UV lamp is on and close the blade when the UV lamp is in use. Anyone who has suffered a sunburn knows some health effects of exposure to ultraviolet light; however, the levels of UV energy around certain UV equipment far exceed the levels found in nature.
Long-wave UV (UV-A) radiation represents up to 95% of the UV radiation that reaches the Earth's surface. UV curing is a rapid curing process in which high-intensity ultraviolet light is used to create a photochemical reaction that instantly cures inks., adhesives and coatings. However, regulations relating to these sources restrict the intensity of UV-C rays to a minimum level and may require the installation of special shields or shields and blocking devices to prevent exposure to UV rays. The Journal of Chemical Health & Safety published an assessment of the UV exposure of light boxes with transilluminators (PDF) that explains the hazards, controls and some common errors.
UV transilluminators or UV light boxes are used in biotechnology for the visualization of nucleic acids (DNA or RNA) after gel electrophoresis and ethidium bromide staining. If there is a possibility that the eyes and face are exposed to UV radiation, a polycarbonate face protector with the ANSI Z87.1-1989 UV certification should be used to protect eyes and face. UV radiation has shorter wavelengths (higher frequencies) compared to visible light, but it has longer wavelengths (lower frequencies) compared to X-rays. Users should be trained on the dangers of UV radiation, the signs and symptoms of exposure, and the proper use of equipment that produces UV rays.
There are several sources of UV radiation in the laboratory, such as germicidal lamps in biological safety cabinets, transillumination boxes for nucleic acids, cross-linkers for nucleic acids and UV lasers. Because of its ability to cause chemical reactions and excite fluorescence in materials, ultraviolet light has a large number of useful applications in modern society. Integral protectors are really the only adequate protection when working with UV light boxes for more than a few seconds.