Health Hazard Evaluation Program PPOP

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?
  • Published a peer-reviewed article on hazards in the cannabis industry, including findings of exposures to allergens, endotoxins, and volatile organic compounds. Additionally, published findings of an evaluation on exposure to secondhand cannabis smoke for law enforcement officers.
  • Supported the CDC coronavirus disease 2019 (COVID-19) response, by visiting 178 workplaces and providing technical assistance to health departments to mitigate the spread of the virus causing COVID-19.
  • Completed site evaluations to assess exposures associated with additive manufacturing technologies (3D printing).
What’s next?
  • Respond to at least 200 HHE and technical assistance requests in 2021.
  • Continue supporting CDC’s response to COVID-19, helping to prevent the spread of the virus that causes COVID-19 among workers.
  • Characterize incidents where first responders experience health symptoms following occupational exposure to illicit drugs.
  • Evaluate exposures to styrene during cured-in-place liner preparation and during water- and steam-curing methods for pipe repair.
  • Evaluate potential hazards during harvesting and trimming of cannabis.
  • Evaluate worker exposures to metals and a perceived excess of cancer cases among workers in a train maintenance facility.

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.

Top 3 Sectors by HHE Request (FY20)
Top 3 Sectors by HHE Request (FY20)

Source: NIOSH program records

Publication Spotlights:  Health Hazard Evaluation Report

NIOSH HHE Program report addressing silica expo-sures during dowel drilling

NIOSH publication addressing safety and health during IEQ and construction and renovation, published 2020

NIOSH publication addressing safety and health during IEQ and construction and renovation, published 2020.

To learn more, visit
August 2021

Page last reviewed: July 29, 2020