Bleach for combless frame sterilization/disinfection; opinions wanted

[westernbeekeeper]

Hello all,
I have a ton of old used frames, mostly no comb, but a few with old comb. I plan to scrape all comb out, not using it because of unknown history. Is it possible to make them safe for reuse by dipping in bleach solution? Please input here. Thanks!

[cowdoc]

When one is talking about 'cleaning and disinfecting' in the academic world and trying to transfer to practical applications, there are important caveats that don't often translate. Cleaning is often the most important part of the phrase, and that is almost impossible to do with wood. That is why hospitals and food prep facilities use so much stainless steel. Wood has lots of pores and crevices that you may or may not be able to see where really small stuff like bacteria can hide and be protected from disinfectants. If you find a scientific paper that says E coli is killed by this disinfectant in .05 seconds, you might think that is good, but if that disinfectant can never get to the E. coli because it is hiding in some wood pores, the scientific paper doesn't matter.

The other problem is the disinfectants can be inactivated. Soil will quickly cause bleach to become worthless. Your first frames may inactivate the bleach for the last ones. So, you may want to look at what will survive the process and still disinfect, and now you are starting to talk about really expensive chemicals that may leave residues and not be all that effective to begin with.

Depending on what the exposure is, there may or may not be anything to clean to begin with. If you are worried about AFB (American Foul Brood), keep in mind that

1. it is not exceptionally common

2. It makes a spore that is highly resistant to most any chemicals. That is why common advice is to burn the hive.

3. You might be able to see evidence of AFB in the comb you are removing, but no on the wood of the frames.

So, if you are worried about AFB, bleach will not work for you.

If you are worried about the protozoans, such as Nosema, which does not make a spore like the bacteria that causes AFB, then time may be the key, bleach may work, but there is not a lot of information available here and I think there may be some work going on as to the persistency of the bug on equipment.

If I were buying used frames and the comb was not available for inspection, the value would probably be the same as kindling. Some will argue not to buy used frames anyways because there are too many questions. If you are worried about AFB, someone could have had spores all through their frames without any signs of disease because they were regularly feeding antibiotics to keep the vegetative form that causes the scales and dead brood from forming.

Hope that wasn't the too long answer to a short question,

Chris Cripps
chris@betterbee.com
800-632-3379 extension 8001
Greenwich, NY

[westernbeekeeper]

So the consensus would be to burn them; is that what I'm hearing? I'm quite fine with that, if that's the advice. I have already burned a handful of the frames, but I stopped because some are in such good shape that I hate to burn them. But if burning them is best, I will do it. Thanks Chris!

[jim lyon]

That's a really good answer Chris. I have heard of beekeepers boiling old frames in lye water. It's a stinky mess and you end up with a frame that has been structurally weakened. Just remember the wood is only about half the cost of a new frame. Do you really want to put new foundation in a hopefully disinfected frame? Personally based on the few pictures you posted I kind of doubt that there is much risk of AFB but why take the risk putting something in your outfit that you might always regret?

[westernbeekeeper]

Well said, Jim. Thanks.

[cowdoc]

The part I wrote asking "what are you concerned with?" is important. If you have looked and are really clear of AFB, perhaps you are ok to use them. If you aren't sure, maybe you don't want to use them at all like Jim said. Personally, I used to use them and now I give them to a friend with a woodstove. Probably best if they do have AFB that they don't sit out on the woodpile also!
Chris
chris@betterbee.com
800-632-3379 extension 8001
Greenwich, NY

[westernbeekeeper]

I have not seen any concrete evidence for foulbrood in the comb. However, I'm not sure I have any good evidence to the contrary. So, I am not sure. I will probably just put them in the burn barrel. I really don't want to regret anything, but yet, what if they are okay? Hopefully I'm being logical and not going in circles.

[Luterra]

In terms of killing AFB spores, gamma irradiation is the best method as it does not damage the wood (or even the comb).

Bleach is not very effective at all, other chemical disinfectants are effective only at very high concentrations.

Heat kills AFB spores effectively, but flaming the surface fails to kill subsurface spores. Effective heat methods include:
--dipping in 320ºF liquid paraffin for 10 minutes
--dry oven at 320ºF for 2 hours (this will "toast" the wood slightly and may cause cracking)
--steam autoclave at 250ºF for 30-60 minutes
http://onlinelibrary.wiley.com/doi/1...376.x/abstract

Mark

[cowdoc]

Luterra,

The question that I would have from your response is where would you go to get irradiation done? I am not aware that it is available in the USA unless you are a food manufacturer/processor with some big $. Otherwise, I thought all that was done in Australia or New Zealand. If you or anyone knows about this being available in USA, it might be interesting to know where and how they are doing it.

Thanks,
Chris
chris@betterbee.com
800-632-3379 extension 8001
Greenwich, NY

[Oldtimer]

Bleach is not very effective at all, other chemical disinfectants are effective only at very high concentrations.

Not quite right there, bleach is very effective, it quickly breaks down AFB spores. But as others have pointed out, cleaning may be the issue. If the AFB spore is in some wax or somehow otherwise protected so the bleach won't get to it, won't work. But if you can get bleach in contact with AFB spores it will work.

I actually did an experiment to confirm this in my mind. I caught a swarm that went into a wooden nuc. Checked it maybe a month later, lousy with AFB to the point the whole ting even smelled bad. The bees and frames were burned, but I decided to try bleach on the box. The box cleaned best I could, and then thouroughly washed in bleach. After drying, a new sacrificial nuc was put in. No AFB sowed up and the nuc is now a hive. I've used the nuc quite a lot, no AFB,

[Luterra]

Here's one option I found in your region:
http://www.montcobeekeepers.org/Pages/Irradiation.aspx

It's not common, and fairly expensive unless you have a large number of boxes to process or you can get in as part of a larger order.

Luterra,

The question that I would have from your response is where would you go to get irradiation done? I am not aware that it is available in the USA unless you are a food manufacturer/processor with some big $. Otherwise, I thought all that was done in Australia or New Zealand. If you or anyone knows about this being available in USA, it might be interesting to know where and how they are doing it.

Thanks,
Chris
chris@betterbee.com
800-632-3379 extension 8001
Greenwich, NY

[squarepeg]

a paper sent to me by the beltsville bee lab stated 275 degrees for two hours would kill afb spores.

i did a medium super this way, and it made the house smell for awhile.

if you could find an old used oven to use outside or in a barn for cheap, you could salvage the frames this way.

[squarepeg]

western, i just looked and i still have that paper beltsville emailed me. if you want it, pm me your email address and i'll forward it to you.

[Luterra]

Not quite right there, bleach is very effective, it quickly breaks down AFB spores. But as others have pointed out, cleaning may be the issue. If the AFB spore is in some wax or somehow otherwise protected so the bleach won't get to it, won't work. But if you can get bleach in contact with AFB spores it will work.

I actually did an experiment to confirm this in my mind. I caught a swarm that went into a wooden nuc. Checked it maybe a month later, lousy with AFB to the point the whole ting even smelled bad. The bees and frames were burned, but I decided to try bleach on the box. The box cleaned best I could, and then thouroughly washed in bleach. After drying, a new sacrificial nuc was put in. No AFB sowed up and the nuc is now a hive. I've used the nuc quite a lot, no AFB,

I should have phrased that more carefully. Based on the study I linked to (not sure if full text is available to the public), submersion in bleach solution (1.55% sodium hypochlorite) for 30 minutes killed 99.97% of surface spores and 99.90% of internal spores. If we assume that all hives have some AFB spores, a 1000-fold reduction in spore load is probably sufficient. Note however that they used untreated pine blocks with no wax or propolis, both of which are hydrophobic and likely to protect spores from aqueous bleach solutions.

By comparison, exposure to 160ºC (320ºF) heat, either by 10-min paraffin dipping or 2 h dry oven treatment, killed 100% of spores.

Mark

[westernbeekeeper]

Thanks everyone, for all the thoughts and input so far.

[linn]

Could you please write the formula for the bleach solution? I was told to use 15% bleach solution. The laundry bleach like Clorax is 10%. I am wondering if the advice was really 15 parts water to one part bleach? Should you dip the frames rather than sponge on the solution?

[Joel]

i did a medium super this way, and it made the house smell for awhile.
.

I think this part of your post goes in the "you might be a beekeeper if" Classic statements section :-)

My memory is fuzzy but I think the New Zealand study spoke about using bleach. Of course then you need to get the mixture right - Bleach at from 10:1 to 40:1 (water :bleach) is very effective for many uses in disinfecting as long as you get it right. The issue you may find is the surface tension in the wrong mixture may actually surround the spores and not kill them. When you speak of not having "concrete" evidence that tells me there might be some evidence. Would you recognize AFB scale in combs? One hive lost to AFB at todays prices, would pay for quite a few new frames and foundation.

[squarepeg]

i think that ben has decided to cull the wax anyway, and is mostly concerned about disinfecting the wood. i emailed him the info from beltsville about how to do that with heat. i can send it to you if you are interested.

lol on the 'might be a beekeeper....", that one almost ended in divorce!

[Riskybizz]

Oldtimer> "No AFB sowed up and the nuc is now a hive. I've used the nuc quite a lot, no AFB, "

Oldtimer that’s an interesting experiment but I wouldn't advise anyone (especially someone inexperienced) to experiment with AFB possible contamination. It is my understanding that AFB spores are always present, and given the right set of circumstances it will manifest itself to a point of visible detection. The correlation could be made that my wife and I were both exposed to strep throat bacteria. My wife developed a bad case of strep as a result of this exposure and became quite ill as a result. I on the other hand was never affected. The assumption could thus be made that my immune system prevented me from the infection. Subsequently, one could raise the same argument that while all bees are subjected to certain viruses and in this case AFB spores, only those with weak immune systems and stress conditions will ultimately allow the spore to become virulent within the colony.

[Oldtimer]

Well kinda, but not really. I used the bleach in a way approved by our government for treating AFB equipment. I've always been very wary of AFB and all my life have never used anything other than complete destruction by burning. So when the bleach way was recommended I was very uneasy people would do it, and not get a good result. So decided to try it myself and monitor closely.

AFB is different to strep, in that you could theoretically get a strep infection from just one bacteria. Not so AFB, it has to be in enough quantity to give a good enough infection to kill at least one larvae, before the infection can take hold in a hive. Not enough, the larvae can be infected but not die, and the infection does not spread.