At the institution from which I am retired, an industrial hygienist would conduct a survey of the UV-A and UV-B intensity in the vicinity of the users' eyes during all stages of the observations when the black light was on -- and then make quantitative recommendations for the degree of protection required.
In the absence of professional IH support, I strongly recommend using protective eyewear that is opaque to UV-A and UV-B light. The visible light creating the "glow" is emanating in multiple directions, but visualized by looking downward. I strongly suspect that UV light is scattered upward from the growth medium, despite its source being from the side.
I hope that others are able to provide more specific policies/procedures.
David Haugen (retired)
From: "Barbara Foster" <bfoster**At_Symbol_Here**WVU.EDU>
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Sent: Thursday, May 3, 2012 8:19:10 AM
Subject: [DCHAS-L] Eye protection when using black lights?
Safety Colleagues:
A faculty member in Biology is proposing a new experiment wherein the undergraduate students would use black lights to determine if certain bacteria "glow". The lamps have aluminum shades so that the light only shines on one side. The students will be directing the lamp over 3 petri dishes, making observations, and then turning off the lights.
What is your policy on eye protection and black light usage in labs? Do you recommend the use of special safety glasses with yellow lenses? If so, please provide details on your choice of PPE and vendor sources.
Best regards,
Barbara