(NOTE: This blog post was archived from the Facebook Fluorescent Mineral Group)
I bought two of these (bulbs) to make a display case for a grandson. They work fine, but it seems they may produce ozone. How do I tell if they do? If they do, is that a (health) problem?
Mark C: You smell it. All UV bulbs produce a little ozone, even the one that say they don't Non-ozone bulbs produce very little, but ozone producing bulbs are obvious to the nose. Yes, it is harmful but dissipates rapidly in the air I think.
Gregory L: Ozone has an odor , you have smelled it definitely being in the hobby as long as you have. I think the ozone production depends on fresh air coming in to react also.
Eric D: I think I read that the tubes made from quartz glass emit less ozone.
Dan M: Shorter wavelength UVC (below about 315 nm) ionizes O2 molecules so glass or quartz that blocks the shorter UVC should produce less ozone. I haven't looked to see if lamp manufacturers provide filter data for their lamps. I do know that my trannie is doing it's part to bring down regional air quality. It cranks out the ozone.
Mark C: “Low ozone” generating lamps transmit up to 90% of their energy at the 254nm wavelength and typically utilize a doped fused quartz that blocks the emission of 185nm energy. Very high ozone” generating lamps are produced using clear fused quartz which allows for the transmission of energy at both 185nm and 254nm wavelengths. The 185nm energy reacts with the oxygen in the air to produce ozone.
Ozone Generator Hazards – InterNACHI
This article describes hazards associated with ozone generators.
Douglas G: Ozone production (purposeful) was part of the system in certain "air purifiers" sold commercially. One even had a setting where it would "sterilize" the air by producing a high level of ozone. During that time limited process you were instructed to leave the room and remove plants and pets to protect them. Like so many things, a little isn't too bad, but too much can really hurt you. Kind of like bathing your lungs in hydrogen peroxide
Douglas G: On a slightly different note; I hope you have shielded your display from direct exposure to this UV light. This one can hurt you badly, from direct exposure to the UV itself. It kill germs by destroying their DNA and can do the same to people, plus frying your retinas.
Mark C: I used to use ozone in my fish tanks (saltwater). It was in an external compartment (skimmer) so that it would not harm the fish. Ozone also used in Jacuzzis (generated by a UV lamp) and bubbled up in the air outlets - small amounts only. At mineral shows I would be surrounded by a thousand watts of UV and the ozone smell was distinct - and I never caught a cold displaying at one of those shows!
Steve S: I Intentionally generated prodigious amounts of ozone in a former water bottling job. Ozone is used to sterilize the water; the bottled well water can still be sold as "natural" as ozone decomposes back to oxygen in around eight hours at room temperature. So my point is: if you seal your display cabinet, only so much ozone can be generated and no more, it won't go anywhere, and it won't continue to build up due to its unstable nature.
Mark C: I would not be locking the ozone inside your case. Ozone is very efficient at blocking UV (think ozone layer). Not good for fluorescence. Of course the higher heat inside the cabinet will help dissipate the ozone quicker, but it still has to affect the fluorescence.
Douglas G: Steve and Mark both inject valid points. There IS only so much oxygen present, which limits the total ozone production, but the ozone DOES block fluorescence, and if one traps it like this there is a risk of someone getting "a big whiff" accidentally and hurting themselves. But the amount of ozone being produced along with the heat generated calls for an active ventilation system for the box, and limited time of operation in a given room size. (Simple chemistry, physics and physiology folks)
Mark C: Keep in mind, most of this discussion relates to ozone producing bulbs. The bulbs we use in our equipment are non-ozone producing (except for poor Graham who started this conversation). If the ozone produced by our bulbs were harmful I would have been fried long ago given the amount of wattage I spend time with...
Don N: UV lamps (some call them bulbs or tubes) are ALWAYS a combination of a ballast (a current limiting device) and a lamp. The lamp that Graham showed has the ballast built into the base. As of a few years ago, no major lamp manufacturer (Philips, Osrum, GE) made germicidal or SW lamps out of quartz (with the possible exception of the special one and two KW municipal water disinfection lamps). Those lamp manufactures use UV-C glass called "soft glass" in the lamp industry. There are smaller lamp manufactures (over 450 in the world) that do make quartz lamps, but not the major lamp manufacturers. And the reason is simple, volume. UV-C lamps (with about 79% transmission at 254 nm) requires just a propane gas to heat and melt the UV-C glass to form the lamp. Quartz lamps (with about 91% transmission at 254 nm) require both oxygen and hydrogen gas to get a hot enough flame to melt or soften quartz so it can be formed into a lamp. The UV-C glass manufacturing equipment can also be used to make there typical fluorescent phosphor lamps since the UV-C glass melds at about the same temperature (using propane) as the soda-lime glass used in those fluorescent lamps. The company that makes the custom made quartz lamps for UV SYSTEMS, Inc. used to have both manufacturing equipment (UV-C glass and quartz), but they switched just to quartz so as not to duplicate their UV lamp equipment.
Don N: Mark is correct about lamp manufactures using two type of quartz tubing. Undoped quartz tubing (used to make germicidal lamps) will transmit the 185 nm Hg arc emission line. 185 nm UV will make LOTS and LOTS of ozone. By doping the quartz tubing when it is being made with a small amount of cesium that will absorb the 185 nm mercury line. The lamp manufactures call quartz "hard glass" even though it is not glass, but quartz. The lamp manufactures also call quartz germicidal lamps made with their cesium doped tubing "Ozone free" even though the 254 nm will produce some ozone. But the amount of ozone generated by 254 nm compared to 185 nm is many orders of magnitude less (at 254 nm). All the quartz lamps used by UV SYSTEMS, Inc. are the "ozone free" (cesium doped) lamps.