UV-C Degredation of Materials

Mark Exley

Mark Exley

Did you know that you can use light from the UV spectrum to render pathogens harmless by affecting their RNA and DNA, preventing them from reproducing?

In particular, UV-C light at 265 nm is used to reduce or stop pathogens. In recent months and years, this technology has become a method to sanitise water, air and the surfaces we touch.

In the current fight against SARS-CoV-2 UV-C light is being used to prevent the virus's spread by sanitising the surfaces and equipment we use.

It is used in hospitals, public transport, office, commercial and residential spaces.

We have recently developed our new Diplomat™ UV-C unit, that provides sufficient UV-C light with 15-seconds exposure to reduce SAR-CoV-2 by up to 99.999%. We created this so users can safely use shared devices for work, learning or play.

However, there are some considerations:

  • Safety in using UV-C
  • Accelerated degradation of plastics caused by UV-C

Using UV-C Light Safel

UV-C light is dangerous when misused, it can burn very quickly and is a known carcinogenic. At LapSafe®, safety is our top priority, and our unit has several safety features to prevent us from being exposed to UV-C light whilst it is in use.

  • UV-C tubes can only be switched on when the door is closed
  • UV-C tubes automatically switched off if the door is opened
  • Failsafe operation
  • Obstruction detection

However, there are also considerations about the item you are 'sanitising' or 'germicidal sterilising'. Some plastics, for example, can degrade when you expose them to UV light. We have all seen our children's plastic toys left in the garden slowly change colour, and eventually become more brittle.

UV-C can affect the longevity of some plastics. The UV-C excites free radicals in the plastic, and they move in a way that can degrade or accelerate the polymer's degradation. With that said, some plastics contain additives to prevent or limit UV degradation, and colour affects the rate of natural UV degradation too. We have all seen red plastics change to almost white under UV exposure, whereas black performs so much better.

We are asked the question: Will my laptop plastics degrade when we UV-C to sanitise them regularly?

The answer is probably yes, to some extent, but there are so many factors that need to be considered to answer any particular customers’ concern.

Some of those factors:

  • Amount of UV-C light
  • Exposure time
  • Type of plastic
  • Plastic molecular structure
  • Plastic UV inhibiting additives
  • Colour of the plastics

It would be best if you asked this question to your laptop or device manufacturer. You should consider if the UV-C exposure will shorten your device's life compared to its expected normal life cycle and if this will result in more laptop/device rotation than usual.

Life Expectancy of Devices

What is a device's acceptable life; 2, 5, 10 or 15 years? We are currently seeing 10-year old machines (which have degraded to some extent due to normal UV light), being brought back into service for our children to have access to a device whilst they learn from home. If machines can last 10 or 15 years with normal UV degradation, is an accelerated degradation of say 5-years acceptable? Is your regular rotation quicker than that? If yes, then UV-C germicidal sanitisation is a possible way forward to a safer environment and a way to get us back to normal sooner.

In conclusion

You should consider the possible additional cost of a heavier rotation of devices v's not providing sufficient devices or facilities for your staff, users, and students to share. There are many white papers, websites and wiki entries that provide an ample selection of material to glean information and knowledge from, in some respects this information is misleading and contradictory. Our advice is to check with your manufacturer for your peace of mind.