Except for the channel operator, there's really not much in place to control offensive behavior. You must be aware that using IRC requires planning and caution. Students must be made aware that using IRC requires them to take personal responsibility, much as they're expected to show maturity and constraint when using the telephone. But there are ways to exercise control. A global curricular conference for kids ages 10-15, conducted in several languages, including English, Spanish, French, Japanese, Norwegian and Hebrew.
Membership is required, but free.