Your Workplace: Secondhand smoke meets the criteria to be classified as a potential cancer-causing agent by the Occupational Safety and Health Administration (OSHA). OSHA is the federal agency responsible for health and safety in the workplace. The National Institute for Occupational Safety and Health, another federal agency, also recommends that secondhand smoke be considered a potential occupational carcinogen. Because there are no known safe levels, they recommend that exposures to secondhand sm oke be reduce to the lowest possible levels.