Here is an excerpt from an article written by Amy Gallo for Harvard Business Review and the HBR Blog Network. To read the complete article, check out the wealth of free resources, obtain subscription information, and receive HBR email alerts, please click here.

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There’s that one person on your team — the bad apple who has nothing positive to say, riles up other team members, and makes work life miserable. If you can’t fire him, how do you respond to his behavior? What feedback do you give? How do you mitigate the damage he inflicts?

What the Experts Say

There’s a difference between a difficult employee and a toxic one, says Dylan Minor, an assistant professor at the Kellogg School of Management who studies this topic. “I call them toxic because not only do they cause harm but they also spread their behavior to others,” she explains. “There’s a pattern of de-energizing, frustrating or putting down teammates,” adds Christine Porath, an associate professor at Georgetown and the author of Mastering Civility: A Manifesto for the Workplace. “It’s not just that Joe is rude. The whole team suffers because of it.” Of course, your first step as a manager should be to avoid hiring toxic people in the first place, but once they’re on your team, it can be hard to get rid of them. “Oftentimes the behavior doesn’t run against anything legal so you can’t fire them if others in the organization don’t agree that a line has been crossed,” Porath explains. Here’s what to do instead.

Dig deeper

The first step is to take a closer look at the behavior and what’s causing it. Is the person unhappy in the job? Struggling in their personal life? Frustrated with coworkers? “You might meet with them and ask how they’re doing — at work, at home, and with their career development,” suggests Porath. If you find there’s a reason for why they’re acting the way they are, offer to help. “A manager can use this information to coach the person, or suggest resources to help address the root of the problem.” For example, adds Minor, if the person is going through a divorce or struggling with a mental health issue, you could offer “counseling resources or time off that could potentially alleviate” the underlying issue.

Give them direct feedback

In many cases, toxic people are oblivious to the effect they have on others. “Most of the time people don’t realize that they’re as destructive as they are,” Porath says. “They’re too focused on their own behaviors and needs to be aware of the broader impact.” That’s why it’s crucial to give direct and honest feedback — so they understand the problem and have an opportunity to change. The standard feedback rules apply: Objectively explain the behavior and its effects, using specific, concrete examples. “It’s not helpful to say, ‘You’re annoying us all,’” Porath explains. “You have to ground it in the work.” Also discuss what kind of behavior you’d like to see instead and develop an improvement plan with the employee. “What do you expect them to change? Strive for clearly defined, measurable goals,” Porath says. “You’re giving them the chance to have a more positive impact on people.”

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Here is a direct link to the complete article.

Amy Gallo is a contributing editor at Harvard Business Review and the author of the HBR Guide to Managing Conflict at Work. She writes and speaks about workplace dynamics. Follow her on Twitter at @amyegallo.