Why does the OU give a hechsher to fresh fruits and vegetables?
Many fruits and vegetables are coated with wax to protect these items and make them appear more appealing. It is possible (though not necessarily the case), that some components of the wax come from non-kosher sources. Nonetheless, in the opinion of the OU Poskim, waxed coatings are inedible and do not pose a kashrus concern. Nonetheless, the OU certifies some raw fresh fruits and vegetables. The OU symbol on these items indicates that the waxes, if used, are fully kosher. The OU on fruits and vegetables provides a service to the kosher consumer who prefers to avoid consuming waxes that are uncertified. This certification does not guarantee that the fruits and vegetables are free of infestation.