Varrox® oxalic acid vaporizer

01 · FIRST, THE LEGAL PART

What may be sublimed in Spain

Subliming oxalic acid is legal in Spain provided you use a registered medicine that covers that route. Today there are two: Varroxal and Api-Bioxal powder. Pure oxalic acid, soaked wipes or any home-made preparation are not medicines, and their use is not permitted.

And one fact worth knowing: the Varroxal datasheet names the Varrox and the Varrox Eddy as examples of a suitable device for application by evaporation. That is not a compatibility we invented.

Nor does it serve for anything else: not formic acid, not amitraz, not thymol. It is an oxalic acid vaporiser.

02 · WHEN TO SUBLIME

Broodless, and cold

Oxalic acid works by contact and does not pass through the capping, so with sealed brood it never reaches the mites inside. Hence the Varroxal datasheet places the treatment in broodless colonies, in autumn or winter, at 2 to 10 °C outside and 2 g per hive. The Api-Bioxal one adds that subliming in summer is not recommended.

The exact figures — dose, number of applications and withdrawal periods — always come from the datasheet of the medicine you use, not from here.

03 · HOW IT IS USED

Two and a half minutes, and ten of waiting

The device goes in through the entrance with the hive closed, is switched on for about two and a half minutes, switched off and left inside for another two. Then it is taken out and dipped briefly in water to cool it, and the hive stays shut for another ten minutes.

It stands about 1 cm tall, so the entrance has to give at least 12-14 mm. And with polystyrene equipment, take care: the plate glows red and EPS melts on contact — it must not rest against the floor or the walls.

04 · PROTECTION

Oxalic vapour is not smoke

This is the part most people skip and the one that allows least argument: a mask with a suitable filter — not a paper dust mask —, goggles, acid-resistant gloves and long sleeves. And never with the wind in your face.

The vapour crystallises as it cools, and those crystals are what attack the airways and the eyes. Protection goes on before you switch on, not when it starts to sting.

05 · BEFORE YOU BUY

It is the device; the medicine and the protection go separately: