This story has some interesting things on food safety:

Cutting boards are another area of concern. Turns out that wooden boards are safer than plastic, because the cellulose in wood absorbs bacteria but won't release it. Plastic absorbs bacteria in a different way. "When a knife cuts into the plastic surface," said Professor Dean Cliver, of the University of California at Davis, " little cracks radiate out from the cut. The bacteria seem to get down into those knife cuts and they hang out. They go dormant. Drying will kill, say, 90% of them, but the rest could hang around for weeks."

Makes sense; that's why plastics that you send through the dishwasher often get dyed the color of things you wash - the plastic absorbs it all. This is the part that runs counter to lots of "conventional wisdom":

In one experiment performed by Professor Cliver, raw chicken juices were spread on samples of used wood and plastic cutting boards. Both boards were then washed in hot soapy water and dried, then knives were used to simulate cutting vegetebles for a salad. No bacteria appeared on the knives cut on wood, but there were plenty on the knives used on a plastic board.

We use glass, which I think obviates the whole issue. But I'm sure a lot of people use plastic thinking it's safer. Sometimes it's what you know that's not so that's most dangerous. Read the rest; fascinating story.