Unless the reason for the differing treatment is due to some form of legally actionable discrimination (i.e. is based on race, religion, nationality, age (over 40), disability or gender), you have no claim here. Absent such discrimination, not all employees need be treated the same or even fairly. This is because most work relationships are "at will". This means that a company or business can set the conditions of employment much as it sees fit. Therefore, allowing some workers smoking breaks and not others is perfectly permissable under the law. The only protection here is if not giving everyone such a break violates the terms of a union agreement or employment contract.