UV Sterilization

Ultraviolet (UV) sterilization is a disinfecting technique that uses UV light to kill or damage microorganisms, such as bacteria, viruses, and fungi.

UV light is an electromagnetic radiation with a wavelength shorter than visible light, but longer than X-ray radiation. The UV light spectrum is split into different types, including UVA, UVB, and UVC. These types vary in wavelength, penetration capabilities, and effects on living organisms.

Types of UV Light

Primarily, UVA contributes to premature ageing, whereas UVB is responsible for causing sunburn. Exposure to these types of UV light is also linked to the increased risk of skin cancer. On the other hand, UVC is used for disinfecting purposes and is not typically a concern for skin exposure as natural UVC is absorbed by the Earth's atmosphere. UVC is extremely effective at killing microorganisms, making it a valuable tool for disinfection and sterilization. UV sterilization has a wide variety of applications including:

• Water treatment to disinfect drinking water.
• Surface sterilization to disinfect laboratory benches and high-contact surfaces in healthcare settings.
• Medical sterilization to disinfect medical equipment, patient rooms or personal protective equipment (PPE).

UV Light and Microorganisms

UVC light sterilizes surfaces by killing or inactivating microorganisms. The mechanism involves disrupting the genetic material of the microorganism.

To begin, the UVC light photons emitted are absorbed by the microorganism. This triggers chemical reactions within the microorganism. Covalent bonds form between adjacent thymine-thymine molecules in DNA, and uracil-uracil molecules in RNA. The formation of these covalent bonds creates structural abnormalities in the DNA or RNA strands. Consequently, genetic replication and function is disrupted. With damaged DNA or RNA, microorganisms are unable to accurately replicate or successfully reproduce. This results in death or inactivation of the microorganism.

UV Sterilization in Laminar Flow Hoods

UV sterilization is commonly used in laminar flow hoods to maintain a sterile environment for various laboratory methods. Laminar flow hoods are designed to provide a contaminant-free environment using filtered air flow to protect sensitive materials, experiments, and samples.

Within a laminar flow hood, UV sterilization is an added layer of protection against contamination. Lamps emitting UVC light, in the range of 200 to 280 nanometres, are integrated into the hood. This feature is activated when the hood is not in use to sterilize and clean the hood before or after an experiment. The inclusion of UV light in our horizontal and vertical laminar flow hood ensures the cleanliness of your workspace is maintained.

Dangers of UV Light

It is important to follow safety precautions when using artificial UVC light as it can be harmful to both the skin and eyes. When the UV light in a laminar flow hood is activated, you should not be present. Necessary PPE should be worn, such as UV-blocking safety glasses and gloves, when handling UVC lamps. The Ossila laminar flow hoods are equipped with a UV safety feature which switches off the light when motion is detected.