If time does not permit air-drying, materials may be frozen. Separate negatives before freezing. Keep under water and send to a professional microprocessing laboratory. Wash off mud or dirt under cold, clean running water. Treat the same as vesicular and diazo microfilm.
Water is especially damaging to magnetic materials.
The longer they are wet, the greater the damage will be. Do not attempt to play any damaged tapes or disks, as they can damage the equipment on which they are being played. Break open the cassettes. Remove floppy disks from their cases. Wash in clean or distilled water.