Radiation, Ionizing and Non-Ionizing

Ionizing radiation is any electromagnetic or particulate radiation capable of producing ion pairs by interaction with matter. It consists of directly or indirectly ionizing particles or a mixture of both. 

Non-ionizing radiation is a series of energy waves composed of oscillating electric and magnetic fields traveling at the speed of light. Non-ionizing radiation includes ultraviolet (UV), visible light, infrared (IR), microwave (MW), radio frequency (RF), and extremely low frequency (ELF). Non-ionizing radiation does not have enough energy to remove an electron from an atom or molecule.

Radiation, Ionizing and Non-Ionizing

Tab/Accordion Items

What is meant by directly ionizing and indirectly ionizing particles?

Directly ionizing particles are electrically charged particles that have sufficient kinetic energy to produce ionization by collision. These include, but are not limited to, electrons, protons, alpha particles (helium nucleus) and beta particles (high energy electrons).

Indirectly ionizing particles are uncharged particles that can release directly ionizing particles or can initiate a nuclear transformation. Examples include, but are not limited to, neutrons and gamma rays.

What are the hazards associated with ionizing radiation?

Overexposure and unprotected exposure to ionizing radiation can result in cellular damage caused by the interaction of directly ionizing and indirectly ionizing particles with the atoms and molecules of tissue. Because directly ionizing particles are charged, they produce ionizations at very short intervals whereas indirectly ionizing particles can penetrate deeper into tissue before interacting by the production of directly charged particles from within and causing further damage.

What are the hazards associated with non-ionizing radiation?

Non-ionizing radiation is found in a wide range of occupational settings and can pose a considerable health risk to potentially exposed workers if not properly controlled. The type of health effects depends upon the frequency and intensity of the emitting source.

The issue of health effects associated with exposure to extremely low frequency non-ionizing radiation is very controversial and no definitive cause and effect has been identified. Radiofrequency and microwave radiation at sufficiently high intensities can cause skin damage through heating. The skin and eyes absorb infrared radiation as heat. Ultraviolet radiation has a high photon energy and may not result in immediate effects. Lasers, which commonly operate in the UV, visible and IR frequency ranges, are a primary skin and eye hazard.

What can I do to protect myself from ionizing radiation?

Never work with ionizing radiation unless you have been trained and are authorized to use it. In addition to the use of proper personal protective equipment, be sure that shielding appropriate to the type of ionizing radiation is in place to isolate the radiation when in use. Always wear passive dosimeters when working with ionizing radiation to monitor the exposure dose received.

What can I do to protect myself against non-ionizing radiation?

Workers should become aware of the type of non-ionizing radiation that they may be using and/or to which they may be exposed and wear the appropriate type of personal protective clothing and equipment (e.g., eye protection with appropriate tint) or take the necessary precautions.

What resources are available to assist employers?

Safety and Health Programs

personal protective equipment hazard assessment can be downloaded and customized to fit an individual workplace.

Training and Outreach Services

The presentations on PPE can be used for employee training. In addition, the education, training and technical assistance bureau provides free online safety and health training and outreach services (i.e., speaker's bureau requests, safety booths) upon request. 

Lastly, the NCDOL Library offers free safety and health videos (including streaming video services) and related research assistance on consensus standards (i.e., ANSI, NFPA, NEC).

A-Z Safety and Health Topics

More resources can be found on the A-Z safety and health topics pages for hazardous waste operations and emergency response and personal protective equipment

Consultation Services

The consultative services bureau provides free and confidential onsite consultation regarding worksite safety and health hazards.

Which standards apply?

OSH has adopted the following standards which are applicable to radiation, ionizing and non-ionizing in North Carolina. Note: Please also check the standards information and activity webpage to see if there has been any recent or upcoming regulatory activity on this topic. 

Ionizing radiation

Non-ionizing radiation

  • General Industry

    • 29 CFR 1910.97 - nonionizing radiation - covers radiofrequency region, including microwaves, but does not cover ultraviolet radiation or infrared radiation

    • 29 CFR 1910.132 - personal protective equipment, general requirements 

    • 29 CFR 1910.133 - eye and face protection 

  • Construction Industry

Other Applicable Standards

The Which OSHA Standards Apply webpage can also help identify other standards that may be applicable to your worksite.

Where can I learn more?

Memorandum of Understanding

  • Through a Memorandum of Understanding between the NC Department of Labor, Occupational Safety and Health (OSH) Division and the Radiation Protection Section (RPS) of the NC Department of Health and Human Services, Division of Health Service Regulation, RPS will be the lead agency for enforcement of worker safety for protection against ionizing radiation.  Accordingly, The NC OSH Division will be the primary enforcement agency for worker exposure to non-ionizing radiation.

Industry Guides

Technical Assistance

If you would like to receive interpretive guidance on this or any other OSH standard or topic, you can submit your questions using the Ask OSH web form, by e-mail to ask.osh@labor.nc.gov or by calling 919-707-7876.