In answer to the title question, I would have to say “not clear” – but likely more than one.

Courts, thankfully, are virtually unanimous in condemning such things.  Unfortunately, they are not so unanimous in their decisions.  Most courts have held that such racial slurs and tropes must occur more than once to make out a hostile workplace.

Once is somehow not enough.

Until a new federal decision came down.

Read my new Above The Law post on this topic.