Bring out the Hellman's

Planning a summer BBQ? Apparently you do NOT need to worry that your guests will come down with food poisoning from spoiled mayonnaise if you serve potato salad or egg salad on a hot day.
This morning a few of us met to decide on the menu for a July picnic for our nonprofit group. Someone suggested potato salad, and predictably someone else raised a concern about food safety. The certified food handler in the group then surprised us all by saying that, yes, back in the old days when people whipped up their own mayo with raw eggs, safety was a concern. But modern commercial mayonnaise, because it contains vinegar, won't spoil in the sun in a few hours.
I did an Internet search and found an excellent interview on NPR's website about this topic with Michael Doyle, a professor of microbiology and direction of the Center for Food Safety at the University of Georgia.