Answer to Question #12035 Submitted to "Ask the Experts"

Category: Ultraviolet Radiation

The following question was answered by an expert in the appropriate field:


I was exposed to radiation from a laboratory germicidal ultraviolet-C (UV-C) lamp twice in the last five months, each time for 30 minutes. I can see wrinkles and peeled skin patches over my face. My chest has four or five cherry angiomas and white spots over the exposed area. I am quite worried about skin effects in the future (in the next 5 to 10 years) from this exposure.


Long-term exposures to UV-C lights can be hazardous; however, your exposures should not be of concern if you begin protective measures before your next use of the safety cabinet.

The safety cabinet you were working in is a standard safety cabinet with a protective safety shield (sash) that can be raised and lowered. This moveable sash is paramount for the cabinet to be considered a safety cabinet. UV-C light is produced within the bulbs contained in the safety cabinet. The UV-C light is used to sterilize surfaces.

UV-C light is known to cause skin-related damages, as well as damage to cellular DNA in the surface skin layers. The damage can be exhibited as a reddening of the skin and in more extreme cases, skin burns and perhaps skin cancers (see Ask the Experts Q9450). Besides these effects, sunlight and UV exposure can accelerate skin aging and wrinkles, similar to that seen with long-term (perhaps years of) exposure to natural sunlight.

Cherry angiomas are small skin growths that contain very small blood vessels that may break and impart red color to the growths. The growths are more prevalent as people age, and there is no specific cause (see Healthline "Cherry Angiomas"). Other skin issues such as skin peeling may be related to UV-C exposure, similar to extreme skin tanning when your skin peels as a result of overexposure to the sun. These issues would only occur on the portions of your body that are directly exposed to the UV-C light.

Your exposures to the UV-C lights most likely occurred when the cabinet sash was in the raised position. In the future, you should lower the sash to a height at which activities in the cabinet can be safely and comfortably performed. If the cabinet draws air from the main room into the cabinet (negative air pressure), you should request your organization's safety and health office to determine the maximum opening for safe operation.

As noted earlier, you should take protective measures before your next use of the safety cabinet. For example, we recommend the safety sash be lowered to protect your face and most of your exposed body as the glass in the sash will block the UV-C light. If possible, turn the UV-C light off any time you will be using the cabinet. We also strongly recommend that you wear either a long-sleeved shirt, a lab coat, or other type of protective clothing that protects your arms, and nitrile gloves to protect your hands. You can use a sunscreen product with a minimum sun protective factor (SPF) of at least 30, if this will not interfere with your procedures in the cabinet. We also recommend that you discuss your exposures with a dermatologist.

A brief search on the internet found several videos regarding the use of safety cabinets, including fume hoods and biological safety cabinets. The basics for these cabinets are similar. The sash is an integral part of their safety. For video examples of the proper use of safety cabinets, please see the following videos:

"Proper Use of a Fume Hood" from the University of California, Berkeley

"Laboratory Safety Guidelines" from the University of Texas, San Antonio

The Occupational Safety and Health Administration (OSHA) also has information on the proper use of biological safety cabinets. Although you did not indicate your exposures were in a biological safety cabinet, the information is still pertinent. Click here for an OSHA fact sheet.

In summary, brief exposure to UV-C light may result in skin peeling, but longer exposures are required to cause the appearance of wrinkles. Furthermore, the appearance of cherry angiomas has no known cause and is more prevalent in people over the age of 30. We recommend you take protective measures such as wearing proper clothing, using gloves, and lowering the safety sash any time you use the safety cabinet.

Paul Charp, PhD

Answer posted on 25 June 2017. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.