Will Heat from Oxalic Acid Vapor Damage Flow Frames?

I am a new beekeeper and I have an experienced keeper coming to treat my hive for varroa mites with Oxalic Acid Vapor. I’ve read that you shouldn’t do this with any type of super on because it could contaminate the honey. I’ve also ready that the extreme heat can cause damage to some frames.

I have a Flow Hive and have 3 questions related to this:

  1. My experienced bee keeper friend tells me that Oxalic Acid is organic and will not cause any harm to the Honey so I don’t have to remove the super. Is this accurate?
  2. Everything I read says not to leave the super on, but how do those bee’s get treated if you don’t leave it on?
  3. Will the heat from the vapor cause damage to the Flow Frames in the Super since they are plastic?

Thanks in advance for any guidance!

I treat with Oxalic in my brood boxes and never in my honey supers. I pull them off or put a flat board in-between. The vapour is in the hive with a closed entrance for 10 minutes so keeping the supers off during that time is not an issue for treatment of your hive. Yes, the bees out foraging and in the honey super don’t get treated, but that is why you treat multiple weeks following the schedule as the bees will get coverage over that period. I like to treat later in the day when it isn’t too hot out and the foragers have returned but I have a lot of hives so it takes me a while to hit them all. The internal temp oft hive rises with the treatment but never to the point that it would impact the flow hive super apparatus if you kept it on. Oxalic is organic but I don’t want to take any risk with things people eat so thats why I don’t leave my supers on.


Thank you for your input Tim. I think I’ll have a deeper conversation with my friend about removing the Super. The bees don’t have much honey in it at this time since it’s such a new hive, but I’m guessing all the empty cells will likely keep a film of acid in them, and then that film will then be mixed with new honey as the bees fill the cells more.

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It is YOUR hive, you have to be in charge of what happens. Simply remove the honey super and set aside before your friend arrives and then there is no argument to be had :slight_smile:


The oxalic vapour itself wont heat the hives. The issue with heat relates to the device, either electric or gas, which is placed in or under the hive to vaporise the oxalic powder. This can get extremely hot and if in contact with hanging wax has been known to set hives on fire.
A little care will avoid this. And yes, remove the super for the few minutes involved, not because the oxalic is harmful, but because its so easy to do.

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