Orientation and Training
Food and Drug Administration
General laboratory safety precautions concerning toxic substances addressed in the ORA Laboratory Manual (Volume III, Section 2, Environmental Health and Safety) and safety considerations regarding mycotoxins should be understood before any laboratory work is conducted. Aflatoxins are suspect carcinogens in humans, and are highly toxic. Trichothecenes are potent dermal irritants and orally toxic. Never dispose of these or any other mycotoxins by pouring their aqueous solutions down the drain or their organic solutions into a waste container. Prior to their disposal, the solutions should be treated with at least one-tenth their volume of 5-6% sodium hypochlorite (household bleach) according to the laboratory's chemical hygiene plan (see Section 7.5 References 18). Swab accidental spills of toxin with 1 % NaOCl bleach, leave 10 minutes, and then add 5 % aqueous acetone. Rinse all glassware exposed to aflatoxins with methanol, add 1 % NaOCl solution, and after 2 hours add acetone to 5 % of the total volume. Allow a 30-minute reaction and wash thoroughly (see Section 7.5 References 19, Chapter 49, Subchapter 1, page 1).
Weighing and transferring mycotoxins in dry form should be avoided; they should be dissolved in a solvent. The electrostatic nature of a number of the mycotoxins in dry form results in a tendency for them to be easily dispersed in the working area, and to be attracted to exposed skin and clothes. Their concentrations should be determined spectrophotometrically. Containers of mycotoxin standard solutions should be tightly capped and their weights may be recorded for future reference before wrapping them in foil and storing them in a freezer (see Section 7.5 References 19, Chapter 49, 971.22E). Keeping records of the weights of stored solutions will provide a means of determining if the solutions have concentrated during storage. To store the material as a film, the solvent should be removed at a moderately elevated temperature under a stream of nitrogen, or by rotary evaporation before freezer storage.