UV or ultraviolet light is a type of electromagnetic radiation that’s divided into three different bands based on its wavelength: UV-A (blacklight blue), UV-B (blacklight or phototherapy), and UV-C (germicidal).
Each band has a unique set of characteristics. So, it’s essential to know which type of UV light is the right one for your needs. None of the UV bands have a common use. Therefore, it can be very dangerous for your health if they are mixed up by accident.
We’ve put together a guide to help you determine the properties of UV-A, UV-B, and UV-C light so that you can decide which one of them is the most appropriate for you.
The Difference Between UV-A, UV-B, and UV-C Light
1. UV-A Light
Discovered by physicist and chemist William H Byler in 1935, UV-A light, also referred to as ‘Blacklight’ or ‘Wood’s Lamp,’ has a wavelength between 320nm and 400nm. It is the closest to the visible light spectrum, and it’s considered to have the longest and safest UV light wavelength out of the 3 bands.
UV-A light is often wrongly associated with blue or violet, since most objects will glow in these colors when illuminated by this type of light. However, UV-A light is invisible to the human eyes, and you cannot see it directly.
You can find these lights in stage installations, nightclub lighting, inspections of banknotes, anti-theft protection, and UV nail lamps. The other two UV light bands do not give this blue and purple glow effect.
Even if blacklight blue bulbs are safer, one should still handle them with care. It’s known that all UV light rays have some effect on your skin: a healthy and safe tan doesn’t exist. So, when working with them, users must wear gloves and avoid long exposure where possible.
2. UV-B Light
It’s very easy to confuse blacklight lamps (UV-B) with the blacklight blue ones (UV-A). However, they’re very different. The UV-B light has a medium wavelength, ranging between 290nm to 320nm. So, it is more harmful than UV-A light.
While the atmosphere absorbs most of the solar UV-B light, it can still affect our body. Luckily for us, it won’t penetrate more than just the superficial skin layer. As a result, many skincare products offer UV-B ray protection.
On a positive note, because the light is biologically active and has slightly shorter wavelengths, it is beneficial in the medical field. It is used in phototherapy to cure certain skin conditions such as eczema, vitiligo, and psoriasis. It is also crucial in criminal investigations for DNA analysis.
A UV-B emitting light bulb is perfect for bug zappers. Insects, flies, and bugs get attracted to the glow coming from these devices. So, the zappers electrocute them as a result. Ink curing solutions and paint also use this type of UV light. Last but not least, some animals even rely on it to absorb calcium.
3. UV-C Light
UV-C light has the shortest wavelength, emitted by UVGI lamps (Ultraviolet Germicidal Irradiation). Its wavelength is between 200nm and 290nm.
Due to its very short wavelength, the ozone layer blocks this type of UV light. So, no natural UV-C light reaches the Earth’s surface. This indeed is fantastic news for us as UV-C rays are incredibly harmful to us.
In general, the shorter the wavelength the more damaging the radiation, and this type of UV radiation especially would target the DNA of microorganisms and cause cells to die.
However, in the late 1800s, it was discovered that UV-C light has the right properties to kill 99% of the germs. As a result, this band of UV radiation can be very beneficial in the medical, industrial, and manufacturing environment.
In a small and controlled amount, it is used in water treatment plants, sterilization, disinfection, and food sanitation. There are also devices such as UV cleansers and UV baby bottle sterilizers that allow the public to sterilize a variety of items. When dealing with UV-C light, it’s important to wear protective clothing as well as keep it away from the body, especially the eyes.
So, now that you’ve learned of the different types of UV rays, lamps, and their uses, you should be able to buy the most appropriate one for you with confidence.