I've been searching for a couple of days regarding radioactivity (as well as levels and potential ill effects) of the Coleman Gold Top and current green top mantles. A thread (Radiation Levels in Some Old and Newer Mantles) makes reference to radioactivity vs. not in specific mantles, but the ones I am looking into are not included. To give you some background info, I got a Coleman 286A this week. It is manufactured in April 2002 and came with a package of two Coleman Gold Top mantles. Due to the lantern being on the newer end, I assumed (wrongly?) that the mantles would not be radioactive. I handled them with my bare hands. The first one that I primed on the lantern I did really slowly (maybe 2-3 minutes to ash) and it gave off a fair bit of smoke. While I didn't sit in the smoke, I guess it's not out of the question that I may have inhaled a puff of smoke or even a tiny piece of ash that may have gone flying. And, quite frankly, that now terrifies me. So, some questions: How much thorium did the Coleman Gold Top mantles 21A101C contain? Do the current green top Coleman mantles that are readily available (Amazon, Canadian Tire, etc.) contain thorium or any other radioactive element? Some Q&As on Amazon say yes, but they're not verifiable sources. Is it mantles made in specific countries that are nowadays radioactive vs. not? Various sources indicate that even the Gold Tops are harmless so long as nothing (smoke or particle) is ingested. How much radiation maybe in one ingested particle? I can't find MSDS for mantles. Do they exist? Do the mantles give off the same amount of radioactivity all the time, or does it decrease over time? i.e., mostly when mantle is primed? Is there an inhaled level that is still considered harmless (something akin to everyday background radiation or trace amounts) or is that wishful thinking? I don't think I'll ever handle a mantle without gloves again!
I cannot edit the post, but just found this on the EPA website (Calculate Your Radiation Dose | US EPA). Annual radiation levels from: - using mantles while camping: 0.003 mrem - chest x-ray: 2-6 mrem - ceramic crown (tooth): 0.007 mrem - smoke detector: 0.008 mrem
Answering my own questions, I found thorough responses in a NUREG/CR-1775 document (applicable screenshots attached). It looks like a camper may be receiving about 0.07 to 0.4 mrem annual exposure from mantles containing thorium, which equals 0.0007 to 0.004 mSv. An example of a child ingesting a mantle gave a 50-year exposure of 16 mrem, which equals 0.16 mSv. I'll stress less now :-o.
No worries. There isn't any Thorium in the Coleman Gold Top mantles. All currently produced Coleman mantles are non-radioactive, the #21A included. The older Coleman Silk Lites are thoriated. They are much sought-after by many collectors of lanterns and stuffs. In fact, many of us here and elsewhere actually prefer the ones containing Thorium. I've personally tested the Coleman #21A as well as some radioactive ones(other brands) with a calibrated Geiger meter but I've lost the pictures that were taken during then. They might probably be somewhere among the older posts of this site. In the tests, I've nullified the background radiation to get a more accurate reading. In most, if not all situations, even the radioactive ones don't pose very serious health hazards. That's provided you don't deliberately inhale the mantle dusts or the fumes during burn-in.
That's helpful info. Based on the packaging and age of the lantern, I do suspect the Gold Tops that I ended up with are 20+ years old. Is there a specific year that Coleman stopped using thorium? I've been reading mixed reports, like at one point half of the ones produced on the US included thorium and the others didn't (???). I actually prefer the slightly yellower light of the green tops I got at Canadian Tire yesterday. More pics from tonight. Really enjoying the lantern now that it's all up and running.
Well generally it is good to handle mantles as if they where radioactive. Without the worry that is. I guess that inhaling parts of any mantle isn't a good idea. Safety tips: - Do not inhale smoke, - Do not eat or drink while handling mantles - Do not blow away ashes - Put remains in a bag and throw away - Wash your hands after handling mantles - wash you hands again Enjoy lam/lantern light.
I am abut to install two Tilley's in our house, expectedly running several hours every day with little ventilation (also want to preserve heat due to current energy prices). I have some chemistry background and don't tend to panic just by seeing a radio label, but made me thinking, as it is significantly more contact than "a few hours camping use a year". My line of thinking: 232Th has a very long half life, it means a very small amount decays. Decay chain here. Daughter elements though are far quicker and combined emit alpha, beta and gamma. This means that thorium ore (might be millions of years old) is more active than the pure metal or purified thorium oxide. Alpha and beta normally doesn't get trough the lamp glass. The only gas in the series is 220Rn, but its half life is measured in seconds, which means even in a confined space it won't live long enough to reach your lungs. I'll follow up the links in this educated answer later, but definitely agree on this, added that I'll keep only a small inventory of mantles and do all handling outside:
Correcting myself after reading the wiki: apparently 224Ra is a culprit as it vaporizes at lamp temperatures. It is alpha-radiating and has a constant supply from the mantle's thorium content. That might present an issue for someone using a Tilley/Coleman/etc indoors, several hours every day.
