Can we refuse to hire smokers?

That depends. In some states, an employee’s right to engage in legal activities is protected, and employers can’t take any adverse employment action against individuals (this includes refusing to hire someone) based on their participation in legal activities during non-work time.

Other states specifically protect an individual’s right to smoke on his or her own time. If either of these is the case in your state, you cannot refuse to hire smokers. However, if your state is one in which neither of these situations is the case, you can make it a policy to refuse to hire smokers, and you can also discipline (up to and including termination) individuals who are smokers, even if they aren’t lighting up on work time or on company property.