Distribution of aflatoxin in pistachios. 6. Seller's and buyer's risk

The seller's risk-the probability of a set of samples exceeding an agreed u pon aflatoxin level when the lot mean does not-and the buyer's risk-the pro bability of a lot exceeding this level when a set of samples do not-have be en computed using a parametrized experimental aflatoxin distribution and Mo nte Carlo simulation. The calculations are exemplified using the proposed E C standards (three 10 kg samples, 4 ng/g of total aflatoxin, basis kernels only) as well as for samples up to 250 kg and for varied lot aflatoxin leve ls. It is found that within this sample size range the seller's risk is as high as 42% at 10 kg and increases with increasing sample size to 80% at 25 0 kg. Only by reducing lot levels to 0.2 ng/g of total aflatoxin, basis ker nels, can the risk be brought down to 2.5%, independent of sample size. The buyer's risk is as high as 58% at 10 kg but falls to 11% at 250 kg samp:le s. The implications for both seller and buyer strategies are discussed.