Health Hazard Evaluation Program

What are our priorities?

The National Institute for Occupational Safety and Health (NIOSH) Health Hazard Evaluation (HHE) Program evaluates potential workplace hazards through field visits and consultations requested by workers, unions, and employers. Based on investigation findings, the HHE Program provides recommendations to improve the health and safety of the U.S. workforce. The HHE Program focuses on these areas:

  • Reducing or eliminating hazards and preventing work-related illnesses
  • Identifying new and emerging hazards
What do we do?
  • Complete timely, high quality investigations that meet stakeholder needs
  • Make and promote relevant, feasible, and effective recommendations to prevent adverse effects of workplace health hazards
  • Raise awareness about hazards, emerging issues, and recommended controls through HHE reports, trade publications and meetings, social media, and scientific publications and meetings
  • Encourage HHE Program requests:
    • From various groups, including small businesses, labor unions, local health departments, and underserved populations
    • That address emerging occupational health problems
    • That are likely to have findings that can apply to many workplaces
  • Encourage research on emerging hazards identified by HHE investigations
What have we accomplished?
  • Made site visits for 22 HHEs and published 33 new HHE reports in 2019, including reports related to:
    • Waste anesthetic gas exposures and reproductive health concerns among employees at a veterinary hospital
    • Chemical and ergonomic hazards among nail salon workers
    • Styrene exposures during ultraviolet cured-in-place pipe installation
    • Firefighters’ health effects after large chemical fire
  • Evaluated work-related health concerns related to potential exposure to illicit drugs among forensic scientists and emergency responders
  • Provided recommendations to the U.S. National Park Service to minimize workers’ exposure to naturally-occurring radon and radon decay products at a tourist cave
  • Provided recommendations to prevent occupational exposures to flavoring chemicals at five coffee roasting, flavoring, and packaging facilities
  • Identified and characterized a previously undescribed severe lung disease that occurred in five workers at a metal machining facility
  • Characterized respiratory health symptoms and inhalation exposures at a rubber manufacturing facility, and provided recommendations to reduce worker exposures
What’s next?
  • Respond to at least 200 HHE requests, including at least 30 initial site visits in 2020
  • Provide expertise to assist the national 2019 Novel Coronavirus response
  • Complete evaluations of potential occupational exposure at multiple sites where additive manufacturing technologies (3D printing) are in use
  • Publish NIOSH document on minimizing indoor environmental problems during construction and renovation projects
  • Recommend controls to prevent silica exposure for workers performing different work tasks
  • Characterize health symptoms and workplace exposures experienced by workers at 17 coffee roasting and packaging facilities
  • Evaluate worker symptoms and building conditions at a law enforcement facility with a history of indoor dampness
  • Provide recommendations to U.S. Customs and Border Protection to help address workers’ occupational safety and health concerns

Mention of any company or product does not constitute endorsement by the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention


The Health Hazard Evaluation Program evaluates workplace exposures and health effects potentially related to hazardous exposures among workers. This snapshot shows recent accomplishments and upcoming activities.

Percent of respondents in 2016-2018 reporting positive changes after HHE
Percent of respondents in 2016-2018 reporting positive changes after HHE

Source: NIOSH Program Records

NIOSH Workplace Solutions addressing preventing occupational exposure to Legionella, published 2019

NIOSH Workplace Solutions addressing preventing occupational exposure to Legionella, published 2019

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October 2020

Page last reviewed: July 29, 2020