type of exposure maximum permissible

dose

Occupational exposures (annual)**

Effective dose-equivalent limit

(stochastic effects) 50 mSv

Dose-equivalent limits for tissues

and organs (non-stochastic effects)

Lens of eye 150 mSv

All others (e.g., red bone

marrow, breast, lung, gonads,

skin, and extremities) 500 mSv

Guidance: cumulative exposure 10 mSv times age

Planned special occupational exposure,

effective dose-equivalent limit*** 100 mSv

Guidance for emergency occupational exposure ****

Public exposures (annual)

Effective dose-equivalent limit,

continuous or frequent exposure** 1 mSv

Effective dose-equivalent limit,

infrequent exposure** 5 mSv

Remedial action recommended when:

Effective-dose equivalent greater than 5 mSv

Exposure to radon and its

decay products greater than 0.007 Jhm^-3 *****

Dose-equivalent limit for lens of

eye, skin, and extremities

Education and training exposures (annual)**

Effective dose-equivalent limit 1 mSv

Dose-equivalent limit for lens of

eye, skin, and extremities 50 mSv

Embryo-fetus exposures**

Total dose-equivalent limit 5 mSv

Dose-equivalent limit in a month 0.01 mSv

Negligible individual risk level (annual)**

Effective dose equivalent per source of

practice 0.5 mSv

*Including background but excluding internal exposures. **Sum of

external and internal exposures, excluding medical exposures. ***Effective

dose equivalent in any one planned event or cumulative effective dose

equivalent in planned special exposures over a working lifetime should

not exceed 100 mSv (10 rem). ****Acute exposures in excess of 100 mSv

(10 rem) are justified only by life-saving actions in emergency situations.

*****Joule hours per cubic metre. ^ indicates exponentiation.

Source: National Council on Radiation Protection and Measurements,

Ionizing Radiation Exposure of the Population of the United States (1987).