This a page where I am compiling notes about Ozone Sterilization of Combs
Ozone for Comb Sterlization?
This was posted on the forum at
www.honeybeeworld.com/forum and I thought it worth posting here for
comment. My initial thoughts follow the quote:
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I have read of other sterilizing combs by spraying a 10% bleach solution on old combs and boxes. Ozone is supposedly a better sterilizer than bleach. It's my understanding that many parts of Europe sterilize drinking water with ozone instead of chlorine.
Has anyone tried sterilizing old combs and boxes with ozone? You can pick up an ozone purifier for hot tubs or aquariums on eBay for $100. If you pumped the ozone into an old chest freezer, you could gas 8 or 10 boxes at once.
Has anyone tried this? How much ozone production do you need to be effective and how long would you need to gas boxes? Or would it be better (more practical) to ozonate the water you mix the 10% bleach solution with and mist combs and boxes?
If you could sterilize combs and boxes in a reasonable amount of time, this might be practical for a sideliner beekeeper. (A commercial beekeeper would likely need one of the larger ozone generator models so they could gas a whole storage room at once.)
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Interesting idea. Gasses are easier to handle in many ways, especially common and disposable ones. Maybe not in California, though.
ETO (Ethylene Oxide gas) was used here in Alberta and Manitoba for a while. Alberta had a huge mobile unit which did 500 boxes at a time. Its use was discontinued due to concerns about the reactivity of ETO and the unknown and potential toxic or carcinogenic by-products possible when placing painted wooden boxes nailed with galvanized nails with beeswax and honey and pollen together with ETO under pressure. Moreover, the process was not completely reliable, since any honey or pollen in frames impeded penetration by the gas. There was always, also, concern for operator safety. ETO is explosive and also it dissipates slowly and the operator must remove the boxes from the chamber at some point. ETO was superseded by electron beam radiation, which is now the sanitizing method of choice in Alberta and BC. It also has problems with penetration if there is much pollen or honey in the combs.
Ozone on a small scale is different from ETO, but can still be dangerous to the operator. Wikipedia -- http://en.wikipedia.org/wiki/Ozone -- says:
"Due to the strongly oxidizing properties of
ozone, ozone is a primary irritant, affecting especially the eyes and
respiratory systems and can be hazardous at even low concentrations. The
Canadian Center for Occupation Safety and Health reports that: "Even very low
concentrations of ozone can be harmful to the upper respiratory tract and the
lungs. The severity of injury depends on both by the concentration of ozone and
the duration of exposure. Severe and permanent lung injury or death could result
from even a very short-term exposure to relatively low concentrations."]"
Using O3 on a small scale could be practical, though, especially since the generator may be cheap to buy and there are no consumables. If the chamber devised is small -- as suggested -- and there is no need to cycle many boxes through as quickly as practicable as there was with large facilities like the ETO chambers we had in Manitoba (stationary) and Alberta (mobile). O3 is heavier than air and clearing the device and the area of ozone before entering or handling boxes in the device would be the biggest concern I can see. A good fan should be able to accomplish this, I would think.
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Rosalind James at the Ogden Bee Lab has been testing ozone fumigations.
Jerry
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> Has anyone tried sterilizing old combs and boxes with ozone?
Many years ago this was raised in Australia when I was on the Honey Research
Council. As I recall the advice we got was that ozone is a good surface
sterilant but has no real penetrating powers. The application in the case
we were looking at was looking at AFB sterilisation.
Trevor Weatherhead
AUSTRALIA
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>Has anyone tried sterilizing old combs and boxes with ozone? You can pick
up an ozone purifier for hot tubs or aquariums on eBay for $100. If you
pumped the ozone into an old chest freezer, you could gas 8 or 10 boxes at
once.
>Using O3 on a small scale could be practical, though, especially since the
generator may be cheap to buy and there are no consumables.
>Rosalind James at the Ogden Bee Lab has been testing ozone fumigations.
++++++++++++++++++++++++++++++++++
Ozone is frequently used in cool stores dealing with fruit, in my case
kiwifruit. Purefresh is one US proprietary system, Smartfresh I think
another. It is used to deplete ethylene, and as a 'cleanser' killing exposed
fungi and bacteria. Kiwifruit in store is particularly susceptible to
ethylene and botrytis rots.
A search for 'cool storage ozone' will start you off and give some idea of
the concentrations used etc. I have not had the chance to throw some bee
boxes in, mostly because in our case (but not elsewhere) we use it in
controlled atmosphere rooms sealed for several months. It is quite routine
and I haven't the slightest doubt that it would work. Fruit being a seasonal
business you may be able to arrange an out of season 'trial' with a local
store when the stores are not being used. Clearly, it will only work on
exposed surfaces, spores and so on buried in wax will be unaffected.
Very low concentrations are used and venting the rooms is not a problem,
safer actually than venting a CA room in some respects. Yes if you want to
clear it quickly a big fan is used. I haven't really thought about it but
the rooms are something like 12,000cubic metres, and safe in less than eight
hours.
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Allen, I have researched ozone sterilization extensively.
Rosalind James in Utah has done the most work. Hard to kill AFB.
Takes a high concentration, far more than any cheap generator can produce.
Does not penetrate well, but will oxidize anything on the surface.
Sensitive to moisture.
Some commercial beeks in Utah have built rooms, but there is little data as
to efficacy.
When venting room, can pass through a catalyst to "neutralize."
Have not yet run trials myself.
Sure wouldn't hurt, and may have effect on viruses and nosema not buried in
pollen or honey.
Frank Eischen found that phostoxin was effective against nosema spores.
Randy Oliver
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Thanks, Randy. Also, today, this came in at honeybeeworld.com:
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After doing some further research, I was able to find this study: http://www.reeis.usda.gov/web/crisprojectpages/415067.html
This year, laboratory experiments in a small fumigation chamber (10 cubic ft) to
determine the concentration of ozone needed to kill honey bee pests and
pathogens. Tests were conducted using 1000 ppm for up to 3 days. Significant
mortality was achieved for chalkbrood, but not for foulbrood. Wax moths
infesting comb (all stages) were also found to be readily killed using 500 ppm
of ozone.
The pesticides coumophos and fluvalinate were significantly reduced by the ozone
treatments, especially at high concentrations. It was difficult to reduce the
pesticides to below 100 ppb. Elimination of pathogens from the comb was also
evaluated. Chalkbrood in non-sporulating bee cadavers placed in the comb was
completely eliminated, and the viability of the spores from cadavers was greatly
decreased by the treatments. Methods to better quantify the actual spore
mortality levels were developed as result, but experiments using these methods
are still underway. Foulbrood scales were also placed in the comb, however,
ozone had no measurable effect on the viability of this pathogen at the test
concentrations used.
While it doesn't appear to have much efficacy against foulbrood, one has to
wonder if ozone would be effective against other viral transmissions via combs
and boxes also since it is effective against chalk.
It is interesting to note the reduction of chemical buildup in the combs of
checkmite and apistan. For beekeepers who are having fertility problems with
drones and queens due to high levels of these chemicals in the combs, this may
be a way of cleaning up old combs.
--- end quote ---
http://www.honeybeeworld.com/forum/viewtopic.php?f=8&t=223&sid=9a8d83318856e57fe5b0975ae80caf4e&p=763#p763
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From
http://www.reeis.usda.gov/web/crisprojectpages/415067.html
KEYWORDS: FUMIGANT STORED COMB AND HIVE
MATERIALS PESTICIDES INSECT PESTS DISEASES POLLINATION HONEY PRODUCTION
CHALKBROOD ASCOSPHAERA APIS FOULBROOD PAENIBACILLUS LARVAE OZONE
PROGRESS: Nov 1, 2008 TO Dec 31, 2009
Progress Report Objectives (from AD-416) To field test, and demonstrate to
Florida honey beekeepers, the use of ozone as a fumigant for decontaminating
stored comb and hive materials from pesticides, insect pests, and diseases.
Approach (from AD-416) Spores of Ascosphaera apis (the cause of chalkbrood in
honey bees) and Paenibacillus larvae (the cause of foulbrood) will be exposed to
different rates of ozone (0.5, 1 and 1.5 mg/kg) for different time periods (24,
48, 36, and 72 hours), and under different temperature and humidity conditions.
The primary purpose of these experiments is to determine whether sterilization
conditions can reasonably be reached by beekeepers in on-farm fumigation
chambers during different times of the year, and in different parts of the
country. This will accomplish a reasonable determination of the exposure
conditions necessary to decontaminate comb of insect pests, pesticide residues,
and bee pathogens. We will select one set of conditions most likely to work for
all these problems under typical Florida weather conditions during the winter.
If warmer conditions are required, then space heaters can be added to the
fumigation chambers. Then, in collaboration with the Florida Dept. of
Agriculture and Consumer Services, Apiary Section, honey beekeepers (or groups
of beekeepers) interested in participating in the project will be identified.
The beekeepers will provide supers of used comb that have suspected or known
contamination problems (e.g. wax moth or small hive beetle infestation,
foulbrood scales, and pesticide exposures). ARS will evaluate and rate samples
of these nesting materials for all these contamination problems. Then the comb
will be placed in a fumigation chamber and treated, as per ARS pre-determined
recommendations. After treatment, the same frames of comb will again be
evaluated for wax moths, small hive beetles, foulbrood, and pesticides to
determine if the treatments were effective. In addition, the treated materials
will be returned to the beekeepers for their use. Beekeepers will be given
instructions for monitoring the effect of treatments on their hives to include:
acceptance of the material by the bees (as compared to untreated controls with
similar contamination problems and as compared to uncontaminated, untreated
comb), honey production, and survival of the colonies. Apiary inspectors will
assist in determining the level of diseases and other health issues, where
possible. Some colonies may be moved out of state for pollination and honey
production, in which case, beekeeper evaluations will be relied on. Significant
Activities that Support Special Target Populations This year, laboratory
experiments in a small fumigation chamber (10 cubic ft) to determine the
concentration of ozone needed to kill honey bee pests and pathogens. Tests were
conducted using 1000 ppm for up to 3 days. Significant mortality was achieved
for chalkbrood, but not for foulbrood. Wax moths infesting comb (all stages)
were also found to be readily killed using 500 ppm of ozone. Plans are underway
to test 2,500 ppm for better pathogen control. Field trials with a commercial
honey beekeeper were conducted using hive materials from the beekeeper.
Initially, the fumigation chamber (3,000 cubic ft) was filled with 280 empty
hives with old comb. However, the beekeepers had difficulty obtaining 1,000 ppm,
so they reduced the number of hive bodies to 180, stacking the boxed by slightly
turning each to allow ventilation between the hives in a stack. A fan was also
placed in the room to circulate the ozone (which is heavier than air). In the
third run, only 120 hives were used. Under these conditions, the beekeepers were
able to obtain approximately 1,500 ppm for five days, but they had some
difficulty with the reliability of the equipment and a technician from the
manufacturer had to be called out on several occasions. The pesticides coumophos
and fluvalinate were significantly reduced by the ozone treatments, especially
at high concentrations. It was difficult to reduce the pesticides to below 100
ppb. Elimination of pathogens from the comb was also evaluated. Chalkbrood in
non-sporulating bee cadavers placed in the comb was completely eliminated, and
the viability of the spores from cadavers was greatly decreased by the
treatments. Methods to better quantify the actual spore mortality levels were
developed as result, but experiments using these methods are still underway.
Foulbrood scales were also placed in the comb, however, ozone had no measurable
effect on the viability of this pathogen at the test concentrations used. Better
equipment for further field trials has been purchased. The ADODR monitored the
progress on this project through various methods including telephone conference
calls, site visits, and meetings to discuss project plans and accomplishments,
validate project expenditures, and provide technical advice.
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> Frank Eischen found that phostoxin was effective against nosema spores.
I had suspected this but had no way to test as I do not use phostoxin.
Beekeepers using phostoxin from the start seemed to have less of a nosema
issue. Especially when restocking deadouts.
My primitive tests seemed to indicate paradiclorabenzine does not kill
nosema spores or at least at the levels I tried. Did frank test para
crystals Randy?
bob
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> Did frank test para crystals Randy?
Nope. Methyl bromide (littel effect), formic acid (some effect), did not
test bleach or ozone.
Randy
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Ozone Testing on Honey Bee Equipment
J Econ Entomol. 2011 Apr;104(2):353-9.
http://www.ncbi.nlm.nih.gov/pubmed/21510179
Potential of ozone as a fumigant to control pests in honey bee (Hymenoptera:
Apidae) hives.
James RR.
SourceUSDA-ARS Pollinating Insects Research Unit, Utah State University, Logan,
UT, USA. rosalind.james@ars.usda.gov
Abstract
Ozone is a powerful oxidant capable of killing insects and microorganisms, and
eliminating odors, taste, and color. Thus, it could be useful as a fumigant to
decontaminate honey comb between uses. The experiments here are intended to
determine the exposure levels required to kill an insect pest and spore forming
bee pathogens. Ozone was effective against greater wax moth, Galleria mellonella
(L.) (Lepidoptera: Pyralidae), even on naturally infested comb. Neonates and
adults were the easiest life stages to kill, requiring only a few hours of
exposure, whereas eggs required a 48-h exposure (at 460-920 mg O3/m3). Two honey
bee, Apis mellifera L. (Hymenoptera: Apidae), pathogens, Ascosphaera apis (a
fungus that causes chalkbrood) and Paenibacillus larvae (a bacterium that causes
American foulbrood), also were killed with ozone. These pathogens required much
higher concentrations (3200 and 8560 mg O3/m3, respectively) and longer exposure
periods (3 d) than needed to control the insects. P. larvae was effectively
sterilized only when these conditions were combined with high temperature (50
degrees C) and humidity (> or =75% RH). Thus, ozone shows potential as a
fumigant for bee nesting materials, but further research is needed to evaluate
its acceptability and efficacy in the field. The need for a reliable method to
decontaminate honey bee nesting materials as part of an overall bee health
management system is discussed.
PMID: 21510179 [PubMed - in process]
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Frank replied:
In the May issue of the American Bee Journal (pages 508-509), we published an abstract of some of our work. Phostoxin was effective in killing nosema spores on stored honeycomb. We are still trying to figure out if ozone will work.
Rosalind replied: (I am only using snips from her message here).
We are working to get it to work in a bigger chamber. It can get very expensive to get a large chamber operational, and it takes a long time to fill it up with ozone. The problem is that the wood adsorbs and degrades the ozone, so when you have a large chamber, you have to produce a lot of ozone very quickly or else you never elevate the amount in the chamber to where you need it. Pesticide degradation is not working as well as I would like it to. Chalkbrood and all the insect pests can be feasibly eliminated 100%. I assume that viruses are as easy to eliminate as chalkbrood but they are very hard to measure. Viruses tend not to be especially persistent outside the host.
... Nosema just is not very stable outside the host either, and so I don’t think fumigation is all that important for Nosema. We are having trouble getting our controls to stay alive long enough to get an experiment set up! Data has shown that Nosema cerana (the main Nosema in the US) only stays viable on comb <30 days. Also, if you put the combs in the cold (we tried storing them at 4C, which is 40F [a typical refrigerator], all the Nosema died within a couple of weeks). Yes, if you take comb from an infested colony and move it directly to an uninfested colony, you will spread the disease. But if you store your honey comb over winter before it goes back on a hive, you are not going to spread the disease.
...This method requires very high concentrations of ozone. If you can walk into the fumigation chamber and live, it is not going to kill other things either! You will need to set up a well sealed chamber, get a machine that produces a large amount of ozone, and pipe the ozone into the chamber. You do not want the generator to be in the fumigation room because ozone at these concentrations is very corrosive, and it will ruin your machine. Also, ozone degrades latex and rubber, so do not use hoses, fan belts, or sealants made from these materials.
It is imperative that you also buy an ozone analyzer that will measure ozone at the desired concentrations. If you do not monitor the ozone level inside the chamber, you won’t know if you are achieving the concentrations that you desire. My general rule of thumb (poorly tested, but this is what seems to be happening):
(1) calculate the volume of your desired chamber,
(2) calculate the total number of grams of ozone you need to fill the chamber at the desired ozone concentration (when the chamber is empty),
(3) now you can calculate the rate at which you need the generator to fill the chamber (i.e. how many grams per hour of ozone do I need to fill my chamber in 12 hours). I suggest you aim for a rate that will fill the chamber within 12 hours or less.
(4) Now the general rule of thumb part: buy a machine that produces ozone at a rate that is 2.5 times that. This is the “wood degrading” factor. If you do not get a machine that produces more than the rate needed to fill an empty chamber, you will never achieve the desired concentration due to the wood and wax of the honey supers and comb—which adsorb and degrade ozone. Also, the less material you put in the chamber, the faster it will fill, and the higher the max possible concentration that can be achieved. And plan to run your machine continuously during the entire fumigation time, venting the extra out through an ozone destructor. This helps maintain the concentration inside the chamber. If you just fill the chamber with ozone, turn the machine off and then leave, the wood and time will degrade it. It really is an unstable product. That is the blessing and curse of it! Blessing because then it does not become a toxin that hangs around on the comb or in the environment.
One caution. Fumigated comb will smell badly. Some dislike it more than others, but the bees do not seem to care. The older and blacker the comb, the more badly it smells. The by products, to the best of my ability to tell (and we did analyze them chemically), are all safe. They just smell.
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