Keep it simple, remember the Three Ps
- While the UVC light is on, the area being disinfected needs to be clear of People, Plants, Pets.
- When using ozone enhancement, the area being disinfected should
remain unoccupied a minimum of 30 minutes up to one hour, after the
light is turned off.
- Should you have to enter the area where a UVC light is on always wear
PPE - see below
UVC Effect on Skin
Acute (short-term) effects include redness or ulceration of the skin. At high levels of exposure, these burns can be serious. For chronic (long-term) exposures, there is also a cumulative risk, which depends on the amount of exposure during your lifetime. The long-term risk for large cumulative exposure includes premature aging of the skin and skin cancer.
Personal Protective Equipment (PPE)
UV radiation is easily absorbed by clothing, plastic or glass. Once absorbed, UV radiation is no longer active. When working with open UV radiation during maintenance, service or other situations, personal protective equipment covering all exposed areas is recommended. When working around UVC devices, one should:
- Use UV goggles and/or full-face shields.
- Prescription glasses and normal safety glasses do not protect eyes from UV exposure, so ANSI Z87 rated eyeglasses with wrap around lens to protect the side exposure is recommended. Consult with ANSI Z87 manufacturers for proper UV exposure protection equipment.
- Cover any exposed skin using lab coats, gloves or other lab attire.
UVC exposure can be reduced through product safety design considerations and controls. For example, safety switches wired in series allow UVC sources to be turned off without exposing workers to UV light. Or placing ON/OFF switches for UVC light sources separate from general room lighting in locations only accessible by authorized persons. Switch locations should be locked or password protected to ensure that the UVC source is not accidentally turned on. Each UVC system should have the option of a viewport so workers can view the lamp assembly without the possibility of over-exposure to UVC.
Proper installation, monitoring, education of maintenance personnel, signage and use of safety switches can help to avoid overexposure. The operating instructions and recommendations for proper use of any UV system should be kept for reference to reduce hazardous exposure. These should be clearly visible for the operators or maintenance personnel and include the temperature and relative humidity ranges specified by the system design to ensure safe operation. Maintenance should be performed according to manufacturer’s instructions electric power should always be turned off to prevent accidental exposure. There are no standard guidelines for monitoring UV equipment, but there are commercial UV monitors that detect output or leakage.
Response to UV Exposure
The effects of acute exposure to UV radiation are usually not severe and many symptoms are delayed. In the event of UV exposure, the following actions are recommended.
- See an ophthalmologist if eye damage is suspected.
- Treat skin lesions immediately.
- Follow your organization’s EHS incident reporting procedure. These often require documentation of the date and time of the incident, persons involved, equipment involved and type of injury.