When someone at work makes a comment that sounds biased, and you’re not sure if they’re being prejudiced or not, it’s hard to know how to deal with the situation. Before you speak up, think about what you really want to achieve — an apology, punishment, repentance? Is it enough for the bad behavior to stop? What kind of relationship would you like to have with the person? Then carefully describe your concerns to the person without judgments, and avoid leveling accusations (“That was racist!”). Describe what actually happened — no apologies, no self-repression, and no indictments. Begin with the facts, calmly suggest what the facts mean to you, and then invite the person to discuss the situation. You can make it safe for them to talk by saying something like “I don’t think you realize how that came across…”
Source: HBR Management Tips
Address Biased Comments at Work Carefully