NIOSH HEALTH 

HAZARD EVALUATION 

(HHE) PROGRAM 

2021 Annual Report
1

HHE Requests in 2021 

130 Requests

Source: NIOSH HHE Program Records

Source: NIOSH HHE Program Records
2

19 Site Visits and Emergency Response Deployments

39 Workplaces 10 States 19 Cities Approx. 48,000 

Miles Traveled

Outreach

HHE website viewed 40,689 times

HHE reports downloaded 16,694 times

7 New HHE reports published

Most downloaded report of 2021 (680 downloads)

Evaluation of Metals Exposure in an Architectural 

Metal Fabrication Shop

https://www.cdc.gov/niosh/hhe/reports/pdfs/2019-0215-3371.pdf

32 Presentations

46 Peer-reviewed publications
3

Examples from 2021

Exposure to Lead During 

Residential Water Line Replacement Activities

A city water department was concerned about lead exposure among 

crews replacing lead water lines servicing residential homes.

What NIOSH Did

• Conducted confidential medical 

interviews.

• Collected personal air samples 

for lead.

• Conducted colorimetric wipe 

sampling for lead. 

Key Findings

• Some employees had elevated 

blood lead levels. 

• Lead was present on employees’ hands and work gloves. 

• Lead was found on surfaces inside trucks and in the locker room. 

Recommendations

Reduce employees’ exposure to lead through improved 

work practices. 

o Improve surveillance, training, and work practices.

o Improve personal protective equipment use/training.

o Implement procedures and further train employees 

to keep their hands clean and free of lead.

o Improve cleaning procedures.

Consider purchasing colorimetric wipe test kits and 

periodically test hands, surfaces, and tools for lead. 

This report is available at: 

https://www.cdc.gov/niosh/hhe/reports/pdfs/2019-0192-3377.pdf

Photo by ©iStock/Getty Images Plus
4

Evaluation of Exposures to Metals and a 

Perceived Excess of Cancer Cases in a 

Train Maintenance Facility

A union at a train maintenance facility was concerned about

employee exposure to metals and a perceived excess of cancer. 

What NIOSH Did

• Spoke informally to employees 

in each support shop about 

health and safety concerns.

• Measured employee exposures 

to metals in the air. 

• Measured blood lead levels of 

electronics shop employees. 

• Administered medical surveys.

Key Findings

• NIOSH found no overexposures to metals, and electronic shop 

employees’ blood lead levels were within the normal range.

• Training and hazard communication could be improved.

• Four employees reported cancer, and all four employees were 

diagnosed with different types of cancers.

Recommendations

Improve communication and training.

Improve hygiene and cleaning practices.

Address other health and safety issues we identified like:

o Spray paint with parts in the appropriate orientation.

o Follow NIOSH criteria when monitoring for noise.

o Remove latex gloves from the facility.

This report is available at: 

https://www.cdc.gov/niosh/hhe/reports/pdfs/2019-0106-3378.pdf

Photo by NIOSH
5 

HHE Program and Virtual Site Visits

During the COVID-19 pandemic, the HHE Program used existing resources and new technologies to help perform site 

visits virtually, allowing for more scalable and flexible use of assets. A virtual hazard assessment could include:

• Performing task-based observations

• Observing work practices

• Assessing hazard controls (e.g., PPE use)

• Conducting medical interviews via

teleconferencing

• Administering questionnaires to workers

Examples 

A company that assembles medical devices with an 

adhesive constructed a small bench-top style exhaust 

ventilation hood to partially enclose the process. 

However, they were unsure of its effectiveness. 

Investigators met virtually with company managers to 

view the assembly process and homemade benchtop 

exhaust hood. This virtual approach permitted:

• Better understanding of the process

• More informed guidance on appropriate local 

exhaust system design for the operation

Investigators virtually toured a pork processing facility 

as part of an HHE evaluating musculoskeletal risks, 

peracetic acid exposures, and COVID-19 mitigation 

strategies. The company had an existing process to use 

a video conferencing platform connected to a helmetcamera. The virtual tour permitted investigators to: 

• Better understand of the scope of the process 

• Inclusion of more NIOSH staff than would 

normally travel to the site (educational 

opportunity for non-project staff)

Challenges

• Helmet camera operator could not hear us

• Could not interact with workers

• Hard to converse with facility noise

• Limited Wi-Fi service caused connection issues
6 

Evaluation of Exposures to Styrene during 

Cured-in-Place Pipe (CIPP) Liner Preparation 

and Pipe Repairs using Hot Water and Steam

The company was interested in characterizing and controlling 

styrene exposures during preparation and installation of CIPP. 

What NIOSH Did

• Observed the work process and 

personal protective equipment use. 

• Assessed exposures and emissions 

of styrene and other volatile 

organic compounds during 

preparation and installation of 

CIPP liners.

Key Findings

• Permit-required confined space entry protocols were not always 

followed. 

• Employees were exposed to styrene emissions from cured liner 

and other process material. 

• Worksite conditions and unexpected process difficulties 

increased employee exposure to the wet liner.

Recommendations

Reduce exposures to styrene and other process emissions.

Monitor employee exposure to styrene during 

short-term tasks.

Continue to educate employees on safe work practices for 

confined space entry, as well as the safety and health 

hazards associated with process ingredients.

This report is available at:

https://www.cdc.gov/niosh/hhe/reports/pdfs/2019-0080-3379.pdf

Photo by NIOSH
7

Evaluation of Indoor Environmental Quality 

and Health Concerns Among Employees of a 

Public Elementary School

Public elementary school employees were concerned that they might 

be experiencing a greater burden of general and reproductive 

medical conditions than was typical.

What NIOSH Did

• Visually inspected every room 

in the school and their 

associated HVAC systems. 

• Measured temperature, relative 

humidity, carbon monoxide, and 

carbon dioxide levels. 

• Interviewed employees about 

their work and their health. 

Key Findings

• No evidence of active mold growth in the school.

• Classroom unit ventilators were approaching the end of their 

expected service life.

• Reproductive medical conditions were not more common among 

school employees compared with the U.S. population or a 

previous study of U.S. teachers.

Recommendations

Prioritize renovating/replacing classroom 

ventilation systems. 

Start an indoor environmental quality 

management program. 

Improve communication to address employee concerns.

This report is available at: 

https://www.cdc.gov/niosh/hhe/reports/pdfs/2019-0156-3382.pdf

Photo by NIOSH
8

What NIOSH is Looking at in 2022
9

The HHE Program Turns 50!

In 2021, the NIOSH HHE Program turned 50 years old! 

Here are some of the highlights since the Program began. 

Requests

• Completed evaluations of over 16,700 requests from workers, 

unions, and employers.

• Conducted evaluations in all 50 states and the U.S. territories of 

Puerto Rico and the U.S. Virgin Islands.

• Produced over 3,000 final reports, which are available on the 

NIOSH HHE Program website and can be searched by title, 

industry, hazard, health effect, state/region, and date.

• Conducted HHEs in nearly every industry sector in small and 

medium sized businesses and large corporations. 

Impact

Workplaces, agencies, organizations, researchers, and others use 

HHEs findings and recommendations to improve worker safety and 

health. Some NIOSH products with an HHE component include:

• Musculoskeletal Disorders in construction and farm workers

• Latex gloves in healthcare

• Hypersensitivity pneumonitis and metalworking fluids

• Flavoring-related lung disease

• Indoor environmental quality in general buildings and schools

• Carbon monoxide poisonings on and around houseboats using 

gasoline-powered generators

Emergency Responses

The HHE Program has provided assistance and expertise to national 

emergencies like the Exxon Valdez oil spill, 9/11, Anthrax, Hurricane 

Katrina, Deepwater Horizon oil spill, Ebola, COVID-19, and more.

Find more information on the 50th Anniversary of the NIOSH Health 

Hazard Evaluation Program at:

https://blogs.cdc.gov/niosh-science-blog/2021/11/18/hhe/.
The mission of the NIOSH Health Hazard 

Evaluation Program is to respond to 

requests from employees, employers, and 

union representatives to evaluate potential 

health hazards in their workplace.

These evaluations are done at no cost to the 

requestor. Once the evaluation is complete, 

recommendations are made on ways to reduce or 

eliminate identified hazards. Health Hazard 

Evaluations can help reduce hazards and 

create healthier workplaces.

If you have questions, please contact the HHE Program

Monday–Friday, 9 a.m. – 4:30 p.m. EST

Phone: 1-513-841-4382

@ HHERequestHelp@cdc.gov

NIOSH Health Hazard Evaluation Program

1090 Tusculum Avenue, Mail Stop R-9 

Cincinnati, OH 45226-1988