The history of using UV-C is a long one. Since scientists discovered, back in the 1870s, that they could harness it to kill microorganisms, artificially produced UV-C has become a staple method of sterilisation in healthcare environments, such as hospitals and medical centres.
Surface disinfection generally requires high-intensity shortwave UV light – that is, UV-C. In healthcare, UV-C (measured at between 100-280nm) can be used for a deep disinfection of surfaces, including floors and walls.
UV-C light can also be used to reduce infections caused by airborne transmission of bacterial pathogens, as equipment supplier UV Light Technology points out. The range of applications for UV-C disinfection of air and surfaces goes far beyond health care, embracing food and retail, schools, transportation, offices, call centres, hotels etc. In other words, across a vast and complex array of environments where such equipment (that is, germicidal UV-C lamps, such as its unit) must be operated, managed and maintained in such a way as to ensure the safety and well-being of everyone who comes into direct or indirect contact with that equipment.
This calls not only for specialist equipment and training, but also a carefully evolved action plan that protects patients and employees when those lamps are active, says UV Light Technology’s sales and marketing manager Dan Arnold. “Our approach at all times is to ensure that ill-health from overexposure to UV light in the workplace, something that often occurs due to misinformation or misunderstanding, is avoided at all costs.
INCREDIBLE SUPPLIERS
“When COVID kicked in, for instance, a number of suppliers entered the market without supplying the necessary information to ensure the safety and well-being of those who were relying on them to provide that advice and guidance, and we were called in on a number of occasions afterwards to put things right.”
Statutory safeguards are in place to protect those who might be exposed, he points out, namely the limits set by the International Commission for Non-Ionising Radiation (ICNIRP). “These are specifically designed to protect individuals from health risks associated with UV exposure to ensure they should not be at an increased risk when going to work,” he adds. “So, wherever UV-C lighting is being employed, organisations have a duty to be compliant with their legal obligations.” Apart from the protection this affords their workforce, “it also ensures they avoid potential compensation claims that may occur from lack of due diligence and compliance”.
ICNIRP exposure limits are based on an eight-hour period (typical working day and similar to natural sunlight hours), taking into account how effective different wavelengths are at producing adverse health effects. “They define a level of UV light exposure, up to which nearly all individuals may be repeatedly exposed without producing adverse acute health effects,” says Arnold. These restrictions are designed to protect the most vulnerable (those with light skin, fair hair and/or those that freckle or burn easy and have significant safety margins built in, bearing in mind that some people may be unusually photosensitive or not have the same natural protection.
What are the possible consequences where organisations fail to enforce these limits? “There are two parts of the body at risk from UV light,” he states, “the skin and eyes, and two types of health risks… acute and chronic. Where the skin is concerned, overexposure can lead to erythema [sunburn] in the short term or, long term, skin ageing (elastosis) or skin cancer. When it comes to the eyes, short-term health risks are photo-keratitis (arc-eye) and/or photo-conjunctivitis, while long-term issues might be ocular melanoma and/or cataracts.”
OPTICAL RADIATION REGULATIONS
The Control of Artificial Optical Radiation at Work Regulations came into law in 2010 and state that, where an employer carries out work that could expose its employees to levels of artificial optical radiation (AOR) that could cause a reasonably foreseeable risk of adverse health effects to employees, the employer must:
Reduce personal exposure to as low a level as is reasonably practicable (ALARP) Calculate personal exposure and compare this with the applicable exposure limit(s) Provide workers with specific information and training.
Relying on equipment manufacturer’s data on exposure times and other operational advice alone is not necessarily sufficient, UV Light Technology points out, as each and every organisation operates differently. It recommends that a series of on-site measurements and assessments (see www.is.gd/ayowon) be carried out. This would typically include:
Measurements and assessment of the UV light process Evaluation of existing control measures, exposure positions and duration Data processing and production of report Maximum exposure times for unprotected skin and eyes Comparison of maximum exposure times (METs) vs actual exposure times (AETs) Recommendations for additional controls to eliminate or further reduce risk Action plan for information and training.
A key benefit of UV-C disinfection is that, as it is based on radiation, it’s a physical, rather than a chemical, process, thus eliminating the need to make, handle, transport or store toxic, hazardous or corrosive chemicals, points out Nico van der Merwe, CEO Signify UKI.
He adds: “When it comes to people safety and selecting the appropriate UV-C disinfection solution, it is really a matter of ‘horses for courses’. With Philips UV-C disinfection active air devices, for example, UV-C disinfection is contained within the unit, so there is no external exposure and the devices can be used with people present, even in UV-C sensitive locations.”
However, Open UV luminaires (fixed to a ceiling) radiate UV-C directly without shielding, meaning no people can be present in the room. A control system and appropriate safeguards are required to be installed to ensure correct and safe usage.
“All disinfection solutions emit UV-C light in varying amounts, which can be harmful in some circumstances,” adds van der Merwe. “That’s why our products are designed with safety in mind, and have very clear installation and usage instructions to avoid exposure to UV-C light, which can damage the eyes or skin. When used by professionals and people with UV experience, Philips UV lamps and devices present minimal risk.”
Its UV-C products come with physically integrated equipment or time safeguards, he says, such as presence or motion detection sensors or timers; or else are to be installed with containment safeguards to enable correct operation.
With Philips UV-C disinfection upper air devices, UV-C is radiated in the higher areas, where it does not reach people, he states. “As a result, normal activities can continue while the device is on.” However, the company also stipulates some operational precautions. “As UV-C is invisible to the eye, the UV-C upper air device must be installed together with adequate safeguards to ensure it can be operated in a safe way.”