Phosphane or phosphorus hydride (PH3) is applied as fumigant to kill storage pests in ware houses or con­tainers. This procedure is legitimate for conventional food, however, for organic foods it causes a problem.

Legal Background
In Germany phosphane, respectively phosphides, are authorised for the treatment of stored cereals, many dried foods like coffee, cocoa, spices, dried fruits, oilseeds or as bait (zinc phosphide) for voles. The application of phosphane is not authorised for organic farming. According to EU Council regulation 834/2007, no residues must be detected in organic foods. As an indication that no application took place, the orientation value of 10 µg/kg of BNN (Bundesverband Naturkost Naturwaren) is used for assessment in Germany. According to Bio Suisse, in Switzerland organically farmed cereals with a content above 1 µg/kg are rejected by authorities.

Analysis
The determination of phosphane at GALAB is carried out with a robust headspace-GC-method with mass spectrometric detection. With this extremely sensitive method we reach a limit of quantification of 0.001 mg/kg phosphane in food.