NASA-STD-3001 Technical Brief

Relevant Technical 

Requirements

Non-Ionizing 

Radiation

OCHMO-TB-045

NASA-STD-3001 Volume 2, Rev D

[V2 6102] RF Non-Ionizing Radiation 

Exposure Limits

[V2 6103] Laser Exposure Limits

[V2 6104] Natural Sunlight Exposure 

Limits

[V2 6117] Artificial Light Exposure Limits

Executive Summary

Non-ionizing radiation (NIR) is one of the 

health risks that astronauts face in spaceflight. 

Sources of NIR that are monitored in an effort 

to protect crew include radiofrequency (RF) 

emitters, natural and artificial incoherent light 

sources, and lasers. As research and 

development activities on the International 

Space Station (ISS) have progressed, NIR 

sources have expanded to include the use of 

stronger lasers and more powerful antennas 

for improved communication capabilities. 

Current NIR safety requirements are based on 

terrestrial guidelines, however the spaceflight 

environment has unique challenges that 

require a proactive, flexible, and highly 

adaptive risk management approach that is 

unique when compared to terrestrially-based 

NIR safety processes. Hardware design and 

controls, health countermeasures, and 

operational controls are all used as part of the 

NASA’s NIR hazard mitigation strategy. 

For additional information, see Human Space 

Exploration: Mitigating the Non-Ionizing Radiation 

Risks in The Lifetime Surveillance of Astronaut 

Health October 2023 Newsletter (Vol 28 Issue 2)

The Space Radiation Analysis 

Group (SRAG) NIR SMEs are the 

agency’s focal point of expertise 

for NIR hazard requirements 

regarding space crew protection 

and are responsible for ensuring 

that the NIR exposure received by 

astronauts in space remains 

below established safety limits; 

and they will continue evaluation 

of the NIR hazards to ensure 

mission success and safe human 

exploration on ISS, outside lowEarth orbit, in cis-lunar space and 

on future missions.
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Background

Non-ionizing radiation is any type of electromagnetic radiation that does not carry enough energy per 

quantum to ionize atoms or molecules directly. Unlike ionizing radiation, shielding from NIR sources can 

be done easily if proper protocol is followed.

02/01/2024 2

From: Lena Lighting - The spectrum of visible light, the wavelength of the light

Sources of Non-Ionizing Radiation

Radiofrequency (RF) Emitters

• Ranging from antennas, wireless systems, satellites, and radiofrequency identifier systems

Natural and Artificial Incoherent Light Sources

• Sunlight (UV, visible, near-IR and IR)

• Artificial Incoherent Light Sources:

• Ultraviolet (UV) (180-400 nm): Produced in welding and carbon arcs, blacklights, sun lamps, 

germicidal lamps, and low/high pressure gas discharge lamps

• Visible (380 – 3000 nm): LEDs, lamps, cabin lighting, display screens

• Near-Infrared and Infrared (770-3000 nm): IR LEDs, heat lamps, IR saunas

NASA’s ILLUMA-T payload communicating with Laser 

Communications Relay Demonstration (LCRD) over 

laser signals.

Source: NASA/Dave Ryan

Lasers

• Continuous wave or pulsed lasers (UV, visible, near-IR and IR)

• Internal or External to ISS, docking lasers, research lasers
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Reference Data

Radiofrequency (RF) Emitters

• A large number of low-power transmitters and high-power antennas are used on the International 

Space Station. The two main areas of concern regarding RF emitters on the ISS are hardware 

interference or damage and crew injury or illness.

• RF exposure can lead to shocks or burns, heating pain or tissue burns, behavioral disruption, heat 

exhaustion or stroke. 

• NASA-STD-3001 Volume 2 establishes limits for RF non-ionizing radiation exposure.

02/01/2024 3

[V2 6102] RF Non-Ionizing Radiation Exposure Limits The system shall maintain the crew exposure 

to RF electromagnetic fields to or below the limits stated in Table 6.8-2—Maximum Permissible 

Exposure (MPE) to RF Electromagnetic Fields and shown graphically in Figure 6.8-1—RF 

Electromagnetic Field Exposure Limits. From: NASA-STD-3001 Volume 2

Frequency Range

(MHz)

RMS 

Electric Field

Strength (E)a

(V/m)

RMS Magnetic 

Field Strength 

(H) a

(A/m)

RMS Power Density (S)

E–Field, H–Field (W/m2)

Averaging Time b

|E|2, |H|2, or S

(min)

0.1 – 1.34 614 16.3/ƒM (1,000, 100,000/ƒM2) c 6 6

1.34 – 3 823.8/ƒM 16.3/ƒM (1,800/ƒM2, 100,000/ƒM2) ƒM2/0.3 6

3 – 30 823.8/ƒM 16.3/ƒM (1,800/ƒM2, 100,000/ƒM2) 30 6

30 – 100 27.5 158.3/ƒM1.668 (2, 9,400,000/ƒM3.336) 30 0.0636ƒM1.337

100 – 300 27.5 0.0729 2 30 30

300 - 5000 – – ƒ/150 30

5000 - 15000 – – ƒ/150 150/ƒG

15000 – 30,000 – – 100 150/ƒG

30,000 – 100,000 – – 100 25.24/ƒG

0.476

100,000 – 300,000 – – 100 5048/[(9ƒG-700)ƒG

0.476]

Note: ƒM is the frequency in MHz; ƒG is the frequency in GHz.

(a) For exposures that are uniform over the dimensions of the body such as certain far-field plane-wave exposures, the 

exposure field strengths and power densities are compared with the MPEs in the table. For non-uniform exposures, the 

mean values of the exposure fields, as obtained by spatially averaging the squares of the field strengths or averaging the 

power densities over an area equivalent to the vertical cross section of the human body (projected area) or a smaller 

area, depending on the frequency, are compared with the MPEs in the table. For further details, see IEEE C95.1-2005, 

notes to Table 8 and Table 9.

(b) The left column is the averaging time for |E|2; the right column is the averaging time for |H|2. For frequencies greater 

than 400 MHz, the averaging time is for power density (S). 

(c) These plane-wave equivalent power density values are commonly used as a convenient comparison with MPEs at 

higher frequencies and are displayed on some instruments in use.

Table 6.8-2—Maximum Permissible Exposure (MPE) to RF Electromagnetic Fields (modified from 

IEEE C95.1-2005, lower tier)
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Reference Data

Natural and Artificial Incoherent Light

• Natural Incoherent Light (Sunlight) – There are many windows on the ISS that provide viewing and 

sunlight exposure to the crew. Sunlight includes UV, visible and IR radiation some of the ISS windows 

(e.g., Cupola) attenuate sunlight to safe levels.

• Exposure to natural and artificial incoherent light sources can lead to retinal thermal damage, macular 

degeneration, and photochemical effects such as corneal sunburn and skin damage.

• Exposure to visible light sources whose luminance does not exceed 10,000 Nits is safe (1 Nit = 1 

Candela per meter squared; 1 Nit = 1cd/m2). Exposure to visible light sources whose luminance 

exceeds 10,000 Nits and is below 10,000,000 Nits is considered of marginal severity. Therefore, the 

ACGIH limits for visible light are required only for artificial sources exceeding 10,000,000 Nits as per 

Table 6.8-4—ACGIH Requirements Applicability. 

02/01/2024 4

[V2 6117] Artificial Light Exposure Limits 

The system shall limit crew exposure from 

Visible, Infrared (IR), near-IR and 

Ultraviolet (UV) artificial light sources 

(180 nm to 3000 nm) at or below the 

threshold limit value (TLV) as calculated 

per ACGIH version 2022 or later.

From: NASA-STD-3001 Volume 2

Requirement/ Damage Mechanism Luminance Value (Nits) ACGIH Calculations Applicability

Visible Light (380-770 nm)

Retina: Thermal

Visible Light (305-700 nm)

Lens, Retina: Photo-chemical

<104 Nits

Eye safe N/A

<107 Nits

Marginal Hazard N/A

≥107 Nits

Critical or Catastrophic Hazard ACGIH calculations needed

IR/Near-IR Light (770-3000 nm)

Cornea, Retina: Thermal N/A ACGIH calculations needed

Ultraviolet (180-400 nm)

Cornea, Lens, Retina, Skin N/A Full Containment or ACGIH 

calculations needed

Table 6.8-4—ACGIH Requirements Applicability

Astronaut Andrew Morgan waters plants in the 

Veg-04B experiment on the space station. This 

space botany research is one of several studies into 

how to provide fresh food for crews on long-term 

space missions. Source: NASA

Reference OCHMO-TB-026 Lighting Design 

for additional information on light sources 

and considerations.
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Reference Data

02/01/2024 5

Requirement/ Damage 

Mechanism Parameter/ Units

ACGIH 2022 

Section/Equation

ACGIH 2022

Pass Criteria

Visible Light (380-770 nm)

Retina: Thermal

Total Effective Radiance

WW · ccmm−2 · ssrr−1

Section 4

[10, 12b1,2, 13a1,2]

Tmax ≥ 0.25 sec

If a>0.1 rad:

LR ≤ 45 WW · ccmm−2 · ssrr−1

If ɑ<0.1 rad:

LR ≤ 4.5·ɑ-1 WW · ccmm−2 · ssrr−1

Visible Light (305-700nm)

Lens, Retina: Photochemical

Effective Radiance

WW · ccmm−2 · ssrr−1

Section 1

[1, 2a1, 32, 4a1, 2]

Tmax ≥ 0.25 sec

If ɑ>0.011 rad:

LB ≤ 400 WW · ccmm−2

If ɑ<0.011 rad:

EB ≤ 0.04 WW · ccmm−2

IR and Near-IR Light (770-

3000 nm)

Cornea, Lens: Thermal

Total Infrared Irradiance

WW · ccmm−2

Section 2

[6, 7b] EIR-only ≤ 0.01 WW · ccmm−2

IR and Near-IR Light (770-

3000 nm)

Retina: Thermal

Total Effective Radiance

WW · ccmm−2 · ssrr−1

Section 2, 3

[8, 9b2]

LNear-IR ≤ 0.6 · ɑ-1

WW · ccmm−2 · ssrr−1

Ultraviolet (180-400 nm)

Cornea Lens, Retina: 

Photochemical

Effective Radiance over 

8 hours

JJ · mm−2

Section “UV 

Radiation” 

[1, 2, 4-7]

See ACGIH Table 1 in this 

section for all TLVs

(delineated per UV 

wavelength)

Ultraviolet (180-300 nm)

Skin (only)

Effective Radiance

JJ · mm−2

Section “UV 

Radiation” 

[1, 3]

See ACGIH Table 2 in this 

section for all TLVs

(delineated per UV 

wavelength)

Note: Refer to ACGIH 2022 for all equations referenced in this table.

1 Assume a 0.25 second aversion response time or calculate Tmax. 2 Dependent on angular subtense, ɑ. See Equation 11 in Section 4.

Table 6.8-5—ACGIH Requirement Compliance and Pass Criteria

The ACGIH requirement compliance and pass criteria are summarized in Table 6.8-5—ACGIH Requirement 

Compliance and Pass Criteria. Although not explicitly stated in ACGIH, the assumed viewing distance is 10 

cm since this is the minimum focus length of the human eye and thus the largest optical power/hazard 

potential on to the retina. ACGIH pass criteria for visible light account for the 0.25 seconds human aversion 

response (i.e., time to look away and/or blink). However, the protection offered by the aversion response 

will not occur if the light intensity is great enough to produce damage in less than 0.25 seconds, as 

explained in the ACGIH. Note: Older than 2014 versions of the ACGIH TLVs cannot be utilized due to 

substantial differences in hazard functions.
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Reference Data

02/01/2024 6

[V2 6104] Natural Sunlight Exposure Limits The system shall maintain the crew exposure to natural 

sunlight for spectral radiance or irradiance (as applicable) within wavelengths between 180 nm and 

3000 nm, as noted in Table 6.8-3—Natural Sunlight Exposure Limits for Different Damage Mechanisms.

From: NASA-STD-3001 Volume 2

Requirement

ACGIH 2014 – TLVs 

Equations in the Optical 

Radiation Section Units Pass Criteria Damage Mechanism

Visible and Near-Infrared 

Radiation 

380-3000 nm

(relaxed 2x)

Equations 4a, 4b

(Section 1)*

Seconds

(Eq. 4a)

Factors over 

allowable 

irradiance 

(Eq. 4b)

Tmax ≥ 0.25s

(Eq. 4a)

Weighted irradiance 

divided by

TLV ratio ≤1

(Eq. 4b)

Retinal Thermal

Visible Radiation 

305-700 nm

(relaxed 5x)

Equation 8b 

(Small Source)

(Section 2)*

Seconds

(Eq. 8b) Tmax ≥ 0.25 sec

(Eq. 8b) Retinal Photochemical

Ultraviolet Exposure 

180-400 nm

(not relaxed)

Equations 3, 4

(Ultraviolet Radiation)*

Minutes

(Eq. 3, Eq. 4)

Tmax > 480 min 

(Eq. 3)

Tmax > 17 min 

(Eq. 4)

Corneal, Skin

*Injury TLVs from visible light presume a dark-adapted pupil with additional factors of safety applied. A minimum safety factor of 2 in the 

spectral radiance Lλ source terms has been included in the ACGIH standard. A minimum safety factor of 5 in the spectral irradiance Eλ

source terms has been included in the ACGIH standard. To eliminate this excess conservatism, the requirement should relax the spectral 

radiance Lλ by multiplying it by a factor of 1⁄2 and the spectral irradiance Eλ by multiplying it by a factor of 1⁄5. Thus, Equations 4a and 4b 

are subjected to the 2x relaxation factor, while Equation 8b is subjected to the 5x relaxation factor. This reduction does not apply to 

ultraviolet radiation. Thus, Equations 3 and 4 are not subjected to any relaxation factors. 

These limits do not apply to laser exposure (see laser exposure limits). Older versions of the ACGIH TLVs should not be utilized due to 

substantial differences in hazard functions. These limits do not account for forced chronic solar viewing.

NOTE: Refer to ACGIH 2014 for all equations referenced in this table. 

Table 6.8-3—Natural Sunlight Exposure Limits for Different Damage Mechanisms

Expedition 51 Flight Crew wearing 

protective sunglasses inside the ISS Cupola. 

The windows inside the Cupola are 

constructed of materials to protect 

crewmembers from UV light exposure. 

Source: NASA 
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Reference Data

02/01/2024 7

Lasers

• Spaceflight programs rely on lasers for a variety of operational and research applications, including 

vehicle docking, optical communications, Light Detection & Ranging (LIDAR), Laser Communications 

Relay Demonstration (LCRD) systems, environmental gas monitoring, fluorescent stimulation, 

extravehicular activities (EVAs), extraterrestrial surface transport vehicles (ESTVs), and intravehicular 

laser science payloads.

• Extravehicular lasers are hazardous to crewmembers conducting EVAs, to crewmembers inside the 

vehicle through windows, and to visiting vehicles that may be approaching to dock. They also pose a 

small risk to the uncontrolled general population through potential use of magnifying optics viewing 

from the ground. 

• Acute exposure to certain powers of laser wavelengths can cause burns to the cornea and/or retina. 

Chronic excessive exposure levels to the eye can lead to the development of cataracts and damage to 

the retina. High amounts of optical radiation in lasers can also lead to skin burns. Additionally, the 

system components of a laser may contain dangerous substances that are flammable and hazardous to 

human health; and create high voltages that could be lethal in unintentional exposure.

• NASA-STD-3001 established a technical requirement to limit crew ocular and dermal exposure to both 

continuous and pulsed lasers to protect against eye and skin injury. The limits are adopted from the 

Laser Institute of America’s (LIA) publication ANSI Z136.1, 2014. The term laser system includes the 

laser, its housing, and controls. This requirement applies to laser systems utilized both internal and 

external to the vehicle. In addition, this requirement limits uncontrolled ground population ocular 

exposure to space lasers. The limits are adopted from ANSI Z136.1, 2014. ANSI Z136.6, 2015, which 

may be used for guidance on laser hazard analysis methodology.

[V2 6103] Laser Exposure Limits The 

system shall maintain the crew ocular 

and dermal exposure to laser systems 

and the ocular exposure of the 

uncontrolled ground population to space 

lasers to or below the limits specified in 

ANSI Z136.1, 2014, American National 

Standard for Safe Use of Lasers, Table 5 

(ocular) and Table 7 (dermal) without 

Personal Protective Equipment. 

From: NASA-STD-3001 Volume 2

Artist's concept showing the Lunar Flashlight spacecraft, a 

six-unit CubeSat designed to search for ice on the Moon's 

surface using special lasers. The spacecraft will use its nearinfrared lasers to shine light into shaded polar regions on the 

Moon, while an onboard reflectometer will measure surface 

reflection and composition. Source: NASA
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Application

Countermeasures

Due to the complexity of space environment operations, nominal terrestrial safety practices (e.g., turn 

laser off for maintenance and troubleshooting; no direct beam viewing for hazardous laser; minimize 

reflective surfaces) cannot be easily implemented. 

02/01/2024 8

Crewmembers are instructed to use NASA 

developed laser and sunlight protection glasses, 

which provide 100% of UV ray blocking and contain 

a special coating to block infrared radiation, during 

all window viewing activities. In addition, the crew 

must not use binoculars or the camera view finder 

when the sun is either in the field of view or 

anticipated to be in the field of view.

One mitigation technique for crew protection 

from RF exposure is to power down the RF 

source while the crewmembers are scheduled 

to execute daily activities near the RF emitter. 

Expedition 43 commander Terry Virts in the Cupola module. 

Source: NASA

ESA astronaut Thomas Pesquet using the Amateur 

Radio on the ISS (ARISS). Source: NASA

Full containment and/or applied 

shielding are acceptable methods of risk 

reduction; however, need to assume 

worst case hazard severity (Catastrophic) 

and corresponding fault-tolerance 

requirements. Containment examples 

include the use of light-tight structures 

and enclosures to fully contain the light 

at the source. The applied shielding must 

be placed between crewmember and 

the light source; examples include 

screens, optical filters, etc.

Astronaut Andrew Feustel delivers the Wide Field Camera 3 to the Hubble 

Space Telescope. Major process improvements were made to supply 

optical filters for the cameras and other NASA imagers. Source: NASA
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Back-Up

02/01/2024 9
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Referenced Technical Requirements

02/01/2024 10

NASA-STD-3001 Volume 2 Revision D

[V2 6102] RF Non-Ionizing Radiation Exposure Limits The system shall maintain the crew exposure to RF 

electromagnetic fields to or below the limits stated in Table 6.8-2—Maximum Permissible Exposure (MPE) 

to RF Electromagnetic Fields and shown graphically in Figure 6.8-1—RF Electromagnetic Field Exposure 

Limits.

[V2 6103] Laser Exposure Limits The system shall maintain the crew ocular and dermal exposure to laser 

systems and the ocular exposure of the uncontrolled ground population to space lasers to or below the 

limits specified in ANSI Z136.1, 2014, American National Standard for Safe Use of Lasers, Table 5 (ocular) 

and Table 7 (dermal) without Personal Protective Equipment. 

[V2 6104] Natural Sunlight Exposure Limits The system shall maintain the crew exposure to natural 

sunlight for spectral radiance or irradiance (as applicable) within wavelengths between 180 nm and 3000 

nm, as noted in Table 6.8-3—Natural Sunlight Exposure Limits for Different Damage Mechanisms.

[V2 6117] Artificial Light Exposure Limits The system shall limit crew exposure from Visible, Infrared (IR), 

near-IR and Ultraviolet (UV) artificial light sources (180 nm to 3000 nm) at or below the threshold limit 

value (TLV) as calculated per ACGIH version 2022 or later.

View the current versions of NASA-STD3001 Volume 1 & Volume 2 on the 

OCHMO Standards website
NASA-STD-3001 Technical Brief

OCHMO-TB-045 Non-Ionizing Radiation

NASA Office of the Chief Health & Medical Officer (OCHMO)

This Technical Brief is derived from NASA-STD-3001 and is for reference only.

It does not supersede or waive existing Agency, Program, or Contract requirements.

Reference List

1. The Lifetime Surveillance of Astronaut Health Newsletter. October 2023 Volume 28, Issue 2. National 

Aeronautics and Space Administration. Available at: https://www.nasa.gov/wpcontent/uploads/2023/10/lsah-newsletter-2023-vol28-issue2.pdf?emrc=65aea3d7666ff

2. Gaza, R. (2023). Invited Plenary Speaker. Challenges of Laser Risk Mitigation for Space Exploration in 

Low-Earth Orbit and Beyond. International Laser Safety Conference, Portland, OR.

3. Gaza, R. (2021). Book chapter: “From Apollo to Artemis: A Laser’s Journey Through Space”, AIP 

Publishing, New York, USA, pp. 4-1–4-14.

4. Flores-McLaughlin, J., Runnells, J., and Gaza, R. (2017). Overview of non-ionizing radiation safety 

operations on the International Space Station. Journal of Space Safety Engineering, 4(2): 61-63. 

5. The Electromagnetic Spectrum: Non-Ionizing Radiation. (2015). Centers for Disease Control and 

Prevention (CDC). Available at: https://www.cdc.gov/nceh/radiation/nonionizing_radiation.html

6. Non-Ionizing Radiation From Wireless Technology. (2023). United States Environmental Protection 

Agency (EPA). Available at: https://www.epa.gov/radtown/non-ionizing-radiation-wireless-technology

7. Omer, H. (2021). Radiobiological effects and medical applications of non-ionizing radiation. Saudi 

Journal of Biological Sciences, 28(10): 5585-5592.

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