Factors in the spread of salmonellas in meatworks with special reference to contamination of knives.

Immersion of knives momentarily in hot water (82 degrees C) was ineffective in destroying salmonellas on knives used in a meatworks to carry out the bung dropping operation. Laboratory experiments confirmed that knives covered with meat products required 10 or more seconds to be effectively decontaminated at this temperature. Examination of knives used for slaughtering and for dressing beef carcases showed that knives coming into contact with hides had higher counts for salmonella and a higher percentage positive than knives used for other cutting operations. Knives used for cutting the skin of the forelegs and hindlegs had the highest counts.