Safety Consideration for the Use of Germicidal Lighting


Germicidal light or UV-C is a part of the light spectrum that cannot be seen or penetrate the ozone layer. UV-C emits ultraviolet radiation with wavelengths between 100 and 280 nanometers.

The technology is to disinfect air, water, food and sterilizes medical instruments, tables, and machinery.

UV-C disinfectant lighting kills bacteria and inactivates viruses, and other microorganisms by disrupting their DNA dismantling reproductive functions. On average, bacteria are dead within 10 seconds when a germicidal lamp is six inches from the object it is treating.

Ideally, the wavelength needed for the highest efficiency is 253.7 nanometers, which labels the germicidal light classification with an augmented wavelength for the best consumption of nucleic acids.

Germicidal UVC lighting produces energy wavelengths shorter than 250 nanometers (particularly 185 nm) and they easily produce ozone, which is necessary when used for the oxidation of organic matter.

Hazards of UV-C Disinfectant Light Radiation

UV radiation (UVR) found in the majority of germicidal bulbs and machinery are dangerous to the eyes and skin.

Consequently, germicidal bulbs cannot be useful in any circumstance that isn’t created to prevent germicidal light exposure to animals or humans.

Germicidal light radiation is not felt immediately. An exposed individual can sustain significant danger without being aware of the activity.

Symptoms usually occur between four hours (after being exposed) and an entire day.

  • There are 2 types of UV-C injuries: acute and chronic. Acute symptoms appear within hours of exposure, while chronic wounds are long-term and can take years to pop up.
  • An acute symptom of UVR is red skin called erythema which is a condition with similarities to sunburns.
  • Rapid skin aging and skin cancer are the most common chronic conditions associated with UVR exposure.
  • UVR saturates the conjunctiva and the cornea damaging the eye and vision.
  • Acute overexposure causes transitory inflammation of the cornea, medically known as photokeratitis.
  • Long-term overexposure to UVR is unusual because of the discomfort it causes for the patient.
  • Continual exposure leads to an advanced danger in contracting ocular cataracts.

Workers Must be Trained and Educated about Germicidal UV-C Technology

Germicidal UV-C is an efficient killer of bacteria and is an effectual agent in inactivating viruses. This is part of the reason it is rumored to be a defense against Corvid-19.

However, there isn’t any research currently to support these claims. Despite the lack of evidence, industries all over the world are investing in UV-C technology.

Hospitals and healthcare facilities routinely use UV-C light to disinfect floors, machinery, and medical instruments. Hotels clean their keys and tools commonly shared among associates. Industrial setting with vast warehouses uses UV-C lamps to sterilize the air in the upper environments of workspaces where it cannot harm employees.

Being exposed to UV-C just minutes may cause harm. Expects can calculate how fast germicidal light exposure produces acute injuries and can help businesses set safety exposure limits. Yet, there is no way to monitor how much chronic exposure will cause long term injuries. These factors make any exposure to disinfectant UV-C dangerous and inefficient for tasks where workers are vulnerable to these dangers.

Germicidal UV-C Lights and Biosafety Cabinets

Biosafety cabinets UV lights are routinely used in labs as a germicide/virucide for the many carbon-based organisms and viruses. UV-C disinfects biosafety cabinets, but UV-C cannot pierce the deeper layers of these surfaces, leaving only the immediate layer sterilized.

Factories, labs, and other well-ventilated and isolated spaces install germicidal UV-C lamps in the high ceilings to cleanse the air and sterilize upper surfaces. However, UV-C is best applied as an additional tool to clean air, direct airflow, and increase the exchange of air.

Personal Protective Equipment & Other Safeguards

Germicidal UV-C light is a considerable opponent for viruses and bacteria, including coronavirus. Yet, the potential dangers associated with disinfectant lighting require a set of safeguards to protect people from acute and chronic injuries caused by ultraviolet radiation.

How to Avoid Injuries

  1. Wear appropriate personal protective equipment to ensure that the risk of UVR exposure is minimized.
  2. Controls of the germicidal lamps should be in separate rooms while access to the disinfectant lamps is controlled.
  3. Entry into any spaces with UV-C lights placed on the ceiling needs to be tightly controlled.
  4. Do not enter the rooms when the lamps are operating.
  5. Turn off UV-C lights before entering any spaces where they operate. Ideally, these lights will have motion detection and shut down immediately.
  6. Ensure that biosafety cabinets and doors have interlocks. Opt for germicidal UV-C lights with have a switch that is interlocked to the entrance where they should only function with a closed door.
  7. Warning signs must display the following: ‘Caution: High-Intensity Ultraviolet Energy. Protect Skin and Eyes.’
  8. The only leakage of UV-C from a biosafety cabinet is the front access point. Ensure there isn’t any leakage by only accessing the inside of the cabinet while the lamp is off.
  9. Don’t leave sashes open while the germicidal lights running because exposure just inches from the biosafety cabinet can cause burns in 15 minutes.
  10. Installing a timer with the UV light will allow enough time for disinfection while researchers and other employees are outside the room.
  11. Thoroughly training personnel to understand the importance of UV-C equipment safety and how to handle the equipment is paramount to protecting people. The necessary safety guidelines should be included in the manufacturer’s manual.
  12. Similar to X-Ray warnings found in hospitals, UV-C warnings should be prominently placed and surround the room where the germicidal lamp resides.


 The Role of Germicidal Lighting in the Battle Against Coronavirus

There is a lot of misinformation when it comes to UV-C and how it can defend against Corvid-19. While there aren’t any current studies that prove UVR does inactive coronavirus, chances are it probably helps.

However, the safety considerations and potential dangers associated with untrained individuals operating UV-C lamps outweigh the benefits this technology might have in protecting masses from the virus.

Germicidal UV-C light is perfect in disinfecting hospital floors, sterilizing drinking water, and cleaning food. Personnel who are knowledgeable, trained and certified to operate disinfectant lights are the only way to utilize this helpful tool.

There is hope for household UV-C applications. David Brenner is a professor of radiation biophysics and director of the Columbia University’s Center for Radiological Research and his team has discovered a tool that creates lower wavelengths of a specific type of UV light called far-UVC. Far UV-C destroys bacteria and inactivates viruses without risk to humans.

The researchers at Columbia University have successfully destroyed two strains of airborne seasonal coronaviruses and they are working to develop germicidal light tools instrumental in slowing the Corvid-19 pandemic.

Leave a comment