Skip to main content
NIH Logo NIH Logo

Office of Research Services

Serving the NIH Community


Exposure Monitoring

The Division of Radiation Safety monitors internal and external occupational radiation exposures from specific radionuclides or radiation-producing equipment for radiation workers employed at the NIH. All results of exposure monitoring are maintained by the DRS and are available to individuals upon request. Personnel exposure reports are sent annually to each radiation worker. ​

Requesting Exposure Monitoring Records

Exposure monitoring records for employers or other agencies outside of the NIH can be obtained by providing a signed, written request to the address below. The request should include your full name, date of birth and/or NIH ID, and dates of employment at NIH. ​​

Personnel Dosimetry Program Manager 
National Institutes of Health 
Division of Radiation Safety 
21 Wilson Drive, MSC 6780 
Bethesda, MD 20982-6780 

Regulation Limits and Exposure Trigger Levels

Occupational radiation exposures are subject to regulatory limits set by the Nuclear Regulatory Commission (NRC) or Occupational Safety and Health Administration (OSHA)​ based on the type of radioactive material or devices used.  Staff who work in both arenas are held to both sets of limits by DRS policy. The NRC has jurisdiction over all occupational exposure if any of the exposure is the result of NRC-regulated activities. 

Notwithstanding these regulatory limits, the NIH Radiation Safety Program works to minimize occupational exposures through the NIH ALARA program​

Regulatory Limits​ 

​Whole Body​
​5 rem/year
​1.25 rem/calendar quarter; Accumulative limit <5 (N-18) rem; N=age
​Lens of the Eye
​15 rem/year
​1.25 rem/calendar quarter
​50 rem/year
​7.5 rem/calendar quarter
​50 rem/year
​18.75 rem/calendar quarter​
​0.5 rem/gestation
​No limit established
​Minor (<18 years old)
​10% of adult limits​
​10% of adult limits​
​General public
​0.1 rem/year; <0.002 rem/hr
​No limit established


Trigger Level Guidelines

To ensure occupational worker safety based on regulatory limits, investigations are performed when occupational exposures from external or internal monitoring results exceed an established trigger level, as noted in the table below. 

Investigations may be formal or informal in nature, depending on the circumstances surrounding the exposure in question. In most cases, exposure values may not be unusual for the work performed.  The DRS investigation results are provided to the individual worker. 


​Level I ​10% dose limits​ ​10% dose limits​
​Level II ​30% dose limits​ ​30% dose limits​
​Level III ​50% dose limits​ 50% dose limits​​

​Related links​