Cool-Tech UVC LED Questions and Answers

Is UVC Light the right choice?

Is UVC Light the right choice to help disinfect your business from bacteria, viruses and harmful pathogens?

The More You Know

With the arrival of the Covid -19 pandemic business has been disrupted all over the world. It has become very clear that we are not immune to disruption from unseen and unwanted pathogens, bacterias, viruses etc. However we must focus on the solutions to maintaining life and business as close to normal as we push forward into the 21st century.

Moving Forward

One clear priority has come about from this pandemic and that is to make sure people are properly protected. The most common protection and prevention method has been through sanitizing products - which have found themselves in high demand and low supply since the arrival of Covid -19.

There has been one overlooked option that is starting to come to prominence (even though it's been used as a highly effective and efficient germ buster since the 1800’s). The use of Germicidal UV Lights.

Unfortunately there has been a lot of confusion and misinformation with regard to Germicidal UV thanks in large part to misguided politicians and online sources.

This guide has been created to clear some of that up and if you can excuse the pun “shed some light� on the benefits of UV lighting as a method of providing sanitation solutions to businesses moving forward.

This guide addresses the current Covid -19 pandemic but also looks to the issues that UVC Lights can help within an ongoing process, providing protection against all different microscopic threats.

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Contents 1: What is UV light and why should you consider it for your business The one thing that has become obvious during the challenge of Covid -19 is how underprepared we as a society are for something so dramatic and sweeping. It is clear that we need better systems and processes to protect ourselves, our families, our employees, customers and society as a whole.

2: Advantages and disadvantages of UVC LEDs Let's take a quick overview of some of the advantages and disadvantages of using UVC LED Lights.

3: Types and effectiveness of UV lighting We will look at the different types of UV lights to give you an idea of which is a best fit for you and your business. In this section we will look to the effectiveness of UVA , UVB, UVC light.

4: Dosing requirements for germicidal UV How much UVC light do you need to sanitize a particular area, here we will look at the factors involved in disinfecting with UVC light including time, intensity and wattage.

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1: What is UVC light and why should you consider it for your business?

UV light as a disinfectant solution has been in the media quite a bit - so much so it seems that it is a new technology.

UVC light has been used to disinfect and keep areas clean and germ free for almost 200 years.

You may not have heard of it, but its applications are commonly used in helping to disinfect air and water in different industries.

Ultraviolet light is part of the electromagnetic spectrum, it occupies the space between 100 and 400 nm. It is outside of the range of the visible and is further broken down into 3 parts. UV light has a wavelength that is shorter than visible light - insects however can see UV light, helping them identify the right flowers and plants.

UV in the Electromagnetic Spectrum Violet Cosmic Rays

Gamma Rays

X-Rays

10-13m

10-9m Vacuum UV

100

Red Infared

Ultraviolet 10-7m

Short Wave UV (UV-C)

185 200

Visible

Micro Waves 10-1m

Middle Wave UV (UV-B)

254 280

300

315

Long Wave UV (UV-A)

Radio Waves (Îťm) (nm)

400

UVA and UVB reach us here on Earth (Sun cream was created to help block the harmful effects of UVA and UVB).

UVC never reaches the Earth's surface thanks to the Ozone Layer. For this reason living organisms such as bacteria, germs, viruses and pathogens have no defence against UVC Light.

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2: Advantages of using UVC LED

• Pathogen Kill Rate is Up to 99.9%. Germicidal UVC LED is highly effective in killing

germs, molds, spores, and bacteria. It disrupts the RNA and DNA in viruses making them inactive and unable to reproduce. UVC is already being used to disinfect air, surfaces, and water.

• No Harsh Chemicals. Typically, a number of different chemicals are used to clean and

disinfect a space. This can be very effective, but it also has its drawbacks and blind spots. Most surfaces are required to stay “wet” for 4 minutes to be effective, but this is rarely done consistently. No matter how good a job a cleaner does, they can never be 100% effective. UVC LED light treatment along with some chemical cleaning has the best chance of complete disinfection.

• Multiple Configurations. There is more than one way to use UVC LED lights as a

disinfectant. They can be wall mounted, ceiling mounted, trolley fixed, or engineered to suit your application.

• Silent Disinfection. Once you have your UVC light configured it's just a matter of

following the safety guidelines. ALWAYS OPERATE IN AN UNOCCUPIED SPACE. This is ‘nature's disinfectant’ and it is a silent killer. Think of it this way you would not go outside naked on a sunny day and stare at the Sun, don't be in the room when the UVC LED is on.

• No Mercury & Ozone Emissions. Both during the operation of the light also no end life disposal issues.

• Minimal Additional Spend. After the initial purchase of the germicidal UVC LED there

are very low operational costs associated with the fixture. Running costs are extremely low as with any LED light.

• Increased Output and Life Span. Up to eight times the UVC output and five times the life span vs. UV fluorescent tube.

• Safety. Alarm device protects workforce from any harmful UVC radiation dosage.

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2a: Disadvantages of using UVC LED

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Not Safe for Humans. UVA and UVB light waves can cause damage to humans though overexposure, especially with regard to the eyes and skin. UVC light waves are to be avoided by humans or any living creature as they are more powerful again. Like chemicals used in disinfectants they will cause damage if exposed to. NEVER BE IN A ROOM UNDER UVC LIGHT. Safety is paramount, always listen and heed manufacturer warnings.

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Strict Guidelines and Product Recommendations. This is not a regular light, its function is to kill harmful pathogens, bacteria, germs, viruses etc. It is not a product you keep in your home where children or careless adults can turn on without knowing.

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Initial Purchase and Setup. As with any functional and quality product there is an up-front cost.

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Can Only kill Germs it can Reach. UVC light can kill and inactivate only what's in its line of light.

If you run a business that frequently serves customers or sees patients, Germicidal UVC LEDs should become part of your safety and cleaning plan.

Our best customer is a well-informed customer. We are here to provide an option and stand by our product. At Cool-Tech we believe in being part of the solution. We offer a line of UV LED products that we believe will make your business safer and cleaner, bringing a sense of security and confidence to you, your employees and customers.

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3: Types and effectiveness of UV lighting

UV UV light is further classified into 3 wavelength ranges:

UV-C

100-280 nm

UV-B

280-315 nm

UV-A

315-400 nm

• NanoMeter: is one millionth of a millimeter. It is equal to 1/1,000,000,000th or one-billionth of a meter. When things are this small, you can't see them with your eyes, or a light microscope.

Objects this small require a special tool called electron microscope (EM) or scanning probe microscope (SEM).

• UVC100-280nm: Is the traditional form of germicidal light. It can kill pathogens including bacteria fungi, spores, mold, germs and disrupt the DNA and RNA of viruses rendering them ineffective. UVC LEDs are highly effective when used in the right applications for the right amount of time. UVC is dangerous to humans and should never be used when anyone is in the direct vicinity of the light when turned on.

• UVB 280-315nm: Although UVB has some germicidal qualities, they are not effective enough to be used as a disinfectant. UVB is most commonly used in tanning beds.

• UVA 315 - 400nm: When you feel the sun on your face you are experiencing the effects of UVA. It is not as effective as killing pathogens as UVC but can still kill bacteria. UVA is a vital source to the health and happiness of humans.

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4: Dosing requirements for germicial UV LEDs How much light is required to disinfect a certain area?

The two main factors to consider here are 1. Time 2. Intensity Measuring the “dose” or “dosage” (the UVC Treatment) is critical to the success of the treatment.

UVC intensity is measured in the units of milliwatts per square meter.

The higher the intensity of the UVC LED the faster it will kill the pathogens.

The light's ability to kill pathogens depends on how far it is away from the surface or surrounding area.

The UVC lamp will inactivate pathogens on a closer surface better than a surface that is further away.

As a visual move a light source closer and further from a surface area and notice the intensity of the light on the surface.

We have developed a UVC measurement tool here at Cool-Tech to calculate the kill rate from our different power rated lamps for the length of exposure time required or available. This can be accessed via our website, based on Esherichia coli 8099 the calculator will produce a scattergraph as illustrated opposite. By moving the curser over the specified room size area you can see the killing rate % for the different power lamps selected over the exposure time inserted into the calculation.

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“Table 1 summarises the results of studies that have been performed on Coronaviruses under ultraviolet light exposure, with the specific species indicated in each case. The D90 value indicates the ultraviolet dose for 90% inactivation.

Although there is a wide range of variation in the D90 values, this is typical of laboratory studies on ultraviolet susceptibility. The range of D90 values for coronaviruses is 7-241 J/m2 the mean of which is 67 J/m2, should adequately represent the ultraviolet susceptibility of the SARS-CoV-2 (COVID-19) virus.”

The table gives a good idea of the different dosage requirements needed to combat different pathogens, germs, bacteria and viruses. According to the Illuminating Engineering Society (IES) in a recent report it outlines the standard for dosage; “17mW of 254 -nm lamp emission radiant power per cubic meter (m3)of space to disinfect air.” This is based on evidence gathered over a period of years with a focus on stopping the spread of tuberculosis.

As you can see there is a lot to consider when looking at UVC LED light as an effective and efficient disinfectant for your business. To help with the confusion one tool which we recommend is the Dosimeter, which can help to determine the effectiveness of UVC disinfection rates around the designated area. Here is a great explainer video from American UltraViolet Healthcare https://youtu.be/TdjjOGA0msE. To find out if UVC Light is the right fit to sanitize and disinfect your business, please reach out to www.cool-tech.co.uk or uvcsanitisingsolutions.com and one of our representatives will help you decide.

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The following summary has been published by ResearchGate.net regarding the susceptibility of Coronavirus to UV light. We have used this data to calculate the exposure time required using the Cool-Tech UVC 4Bay sterilizer lamp.

Table 1: Summary of UV light studies on Coronaviruses Microbe

D90 Dose (Exposure) Required

Source

Coronavirus

7 J/m2

Walker 2007

Berne virus (Coronaviridae)

7 J/m2

Weiss 1986

Murine Coronavirus (MHV)

15 J/m2

Hirano 1978

Canine Coronavirus (CCV)

29

J/m2

Saknimit 1988

Murine Coronavirus (MHV)

29 J/m2

Saknimit 1988

SARS Coronavirus CoV-P9

40

J/m2

Murine Coronavirus (MHV)

103 J/m2

Liu 2003

SARS Coronavirus (Hanoi)

134 J/m2

Kariwa 2004

SARS Coronavirus (Urbani)

241 J/m2

Darnell 2004

Average

67

Duan 2003

J/m2

Application

Reference value

Central Point Radiation Intensity

4 Bay UV-200W, Distance 1M, 1 Hour

2709 J/m2

75.26uW/cm2

4 Bay UV-200W, Distance 2M, 1 Hour

677 J/m2

18.82uW/cm2

4 Bay UV-200W, Distance 3M, 1 Hour

301 J/m2

8.36uW/cm2

4 Bay UV-200W, Distance 4M, 1 Hour

169

J/m2

4 Bay UV-200W, Distance 5M, 1 Hour

108 J/m2

4.7uW/cm2 3.01uW/cm2

4 Bay UV-200W, Distance 4M, 10 Minutes

28.2

J/m2

4.7uW/cm2

4 Bay UV-200W, Distance 4M, 20 Minutes

56.4 J/m2

4.7uW/cm2

4 Bay UV-200W, Distance 4M, 30 Minutes

84.6

J/m2

4.7uW/cm2

4 Bay UV-200W, Distance 4M, 90 Minutea

253 J/m2

4.7uW/cm2

J/m2

4.7uW/cm2

4 Bay UV-200W, Distance 4M, 2 Hours

338

4 Bay UV-150W, Distance 4M, 2 Hours

254 J/m2

3.53uW/cm2

4 Bay UV-100W, Distance 4M, 2 Hours

169

J/m2

2.35uW/cm2

4 Bay UV-50W, Distance 4M, 2 Hours

85 J/m2

1.18uW/cm2

Table 1 above summarises the results of studie that have been performed on Coronaviruses under ultraviolet light exposure, with the specific species indicated in each case. The D90 value indicates the ultraviolet dose for 90% inactivation.

Although there is a wide range of variation in the D90 values, this is typical of laboratory studies on ultraviolet susceptibilty. The range of D90 values for coronaviruses is 7-241 J/m2 the mean of which is 67 J/m2, should adequately represent the ultraviolet susceptibility of the SARS-Cov-2 (COVID-19) virus.

By using the exposure data, and comparing the UV light irradiance measurements from our UV disinfection lamps and systems, we can easily calculate the exposure times required to achieve a particular log reduction based at specified distances from the source.

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This data is based using a 4Bay UV 200W sterilizer lamp at a height of 4 metres, a room size of 10x10 metres and wavelength of UVC 275nm.

Species

Bacteria

Mould & Spore

Virus

Microorganism

Duration at 99% killing rate

Escherichia coli

40 min

Bacillus anthraci

30 min

Bacillus tetani

35 min

Staphylococcus

120 min

Dysentery bacilli

20 min

Mycobacterium tuberculosis

40 min

Vibrio cholerae

65 min

Salmonella

55 min

Aspergillus

75 min-700 min

Penicillium

90 min-300 min

Mucor

480 min

Other penicillium species

90 min

Sporophilic virus

20 min

Hepatitis b virus

80 min

Influenza virus

30 min

Note the above results were calulated according to the relevant literature and relevant data. the references are as follows: Wenjun Sun, Study on biosafety of ultraviolet disinfection of drinking water [D]. Tsinghua university, 2010.

Koivunen J, Heinonen-Tanski H, Inactivation of enteric microorganisms with chemical disinfectants, UV irradiation and combined chemical.UV treatments. Water Res, 2005, 39(8): 1519-1526.

Hijnen W, Beerendonk E, Medema G inactivation credit of UV radiation for viruses, bacteria and protozoan (oojcysts in water: a review. Water Res, 2006, 22 (3):3-4.

Leinberger J, Data summarized from the US EPA Workshop on UV Disinfection of Drinking Water, April 28-29, 1999, Arlington, VA. Keller R, Passamani F, tertiary effluents by UV Vaz L. et al. Inactivation of irradiation, Water Sci Technol, Salmonella spp. from secondary and 2003, 47(3):147-150.

Gerba C P, Gramos D M, Nwachuku N.Comparative inactivation of Enteroviruses and Adenovirus 2 by UV light. Appl Environ Microbiol, 2002, 68(10): 5167-5169.

Thurston-Enriquez JA, Haas CN, Jacangelo J, et al. Inactivation of feline Calicivirus and Adenovirus Type 40 by UV radiation.

Appl Environ Microbiol, 2003, 69(1):577-582.

Ko G P, Cromeans T L, Sobsey M D. UV inactivation of Adenovirus type 41 measured by cell culture mRNA RT-PCR, Water Res, 2005, 39(15): 3643-3649.

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