Products
Oxalic acid is available as a pure substance in pharmacies and drugstores. Various veterinary medicines (antiparasitics) containing oxalic acid are available, for example, in the form of powders and solutions. Oxalic acid has been used against varroa mites since the 1980s.
Structure and properties
Oxalic acid (C2H2O4, Mr = 90.0 g/mol) is a natural organic acid found, for example, in spinach, rhubarb, parsley, chives, beetroot as well as honey. It belongs to the dicarboxylic acids and is their simplest representative (HOOC-COOH). It is often present as oxalic acid dihydrate (- 2H2O), a white, crystalline, and odorless powder with an acidic taste that is readily soluble in water. Its salts are called oxalates. Commercially available oxalic acid is produced artificially.
Effects
Oxalic acid (ATCvet QP53AG03) has acidic, corrosive, and antiparasitic (acaricidal) properties. The effect against varroa mites is based on the fact that it is an acid. Oxalic acid acts only against mites that are on the bees. It shows no effect on mites in the capped brood.
Fields of application
The areas of application include (selection):
- As a veterinary medicine for the treatment of varroosis (infestation with ) in honey bees in broodless colonies.
- For the production of active ingredient salts (eg escitalopramoxalate).
- For cleaning crystals and removing rust stains.
Dosage
According to the instructions in the package leaflet of the finished medicines. As a veterinary drug, the oxalic acid is drizzled, sprayed or vaporized, among other methods. The drip treatment is the most commonly used. For this purpose, the acid is mixed with sugar, which significantly increases its effectiveness. The time of application is late autumn (winter treatment).
Precautions
Oxalic acid is toxic and must not come into contact with the skin, eyes, mucous membranes or respiratory tract. It should not be ingested. When handling, the appropriate precautions in the Material Safety Data Sheet should be observed. Protective clothing, gloves, goggles and protective mask (FFP2 SL) are recommended. The respiratory masks are particularly necessary when spraying or vaporizing. Wash any exposed skin immediately with soap and plenty of water. In case of accidental ingestion, rinse mouth with plenty of water and drink plenty of water or milk. Contact a physician. Oxalic acid must not be allowed to enter water bodies as it may be a hazard to fish and other aquatic organisms. It must be kept out of reach of children. For complete precautions, refer to the Drug Information Leaflet and Safety Data Sheet.
Adverse effects
Oxalic acid is corrosive and acidic and may cause irritation or burns to the skin, eyes, and mucous membranes if used improperly. Slightly elevated levels of oxalic acid may be detected in honey as a result of treatment. However, these are within the range of naturally occurring concentrations. In many cases, however, the values are also normal.
