Workplace smoking laws apply to all indoor workplaces.
Smoking is prohibited in all indoor workplaces. Smoking is permitted in outdoor areas, if employer permits. However, the employer is free to make the entire workspace smoke-free.
In Pennsylvania, smoking areas must have a "smoking permitted" sign.
Pennsylvania doesn't specifically require employers to provide workplace accommodations for nonsmoker employees.
Pennsylvania laws don't address employer policies on smoking in the workplace. Local laws regulating smoking -- at the city, county, or town level -- may require employers to have a policy on smoking in some areas. And even though it's not required by law in Pennsylvania, employers are generally free to adopt policies on smoking in the workplace if they choose to.
An employer may not discharge an employee, refuse to hire an applicant for employment, or retaliate against an employee because the individual exercises a right to a smoke-free environment.
If you want to go right to the source and look up Pennsylvania law on workplace smoking laws -- or if you're writing a letter to your employer or employee and want to cite the applicable law -- the relevant statute(s) can be found at 35 Pa. Cons. Stat. Ann. Sections 637.2 to 637.11. Workplace smoking information is also available in Nolo's books Your Rights in the Workplace, by Barbara Repa (Nolo) and The Employer's Legal Handbook, by Fred Steingold (Nolo).