Chapter 43

NON-IONIZING RADIATION

Contents

Approved by Greta Toncheva
Revised 5/18

43.1 Policy
43.2 Scope
43.3 Applicability
43.4 Exceptions
43.5 Roles and Responsibilities
43.6 Definitions
43.7 Required Work Processes

Work Process A. Non-ionizing Radiation Flowchart
Work Process B. Exposure Limits     
Work Process C. Methods of Exposure Control
Work Process D. Additional Information

43.8 Source Requirements
43.9 Reference Documents

NOTE:
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43.1 Policy

The Lawrence Berkeley National Laboratory (Berkeley Lab) Non-ionizing Radiation (NIR) Program is designed to provide a safe working environment for staff that ensures NIR exposure does not exceed the Threshold Limit Values (TLV) for the human eye or skin. The NIR Program at Berkeley Lab ensures personnel are protected from NIR exposure hazards including:

Note: Laser and acoustic (noise) exposures are covered in separate policies.

43.2 Scope

Non-ionizing Radiation (NIR) refers to electromagnetic radiation with insufficient energy to release a bound electron from an atom. NIR includes the following categories of radiation: ultraviolet (UV), visible light, infrared, radio frequency, microwave, and magnetic fields. (Lasers are covered in the Laser Safety Program.)

43.3 Applicability

This program applies to Berkeley Lab employees, casual and participating visitors, affiliates, and subcontractors who may perform work in or around NIR sources with the potential for an over exposure.

43.4 Exceptions

Laser work is covered by the Laser Safety Program.

43.5 Roles and Responsibilities

Role

Responsibilities

Division Director

Ensures the NIR Program is enforced

Environment, Health & Safety (EHS) Division

  • Arranges or performs NIR assessment as requested or determined by an approved activity within the Work Planning and Control (WPC) system or other authorization method
  • Establishes controls for NIR hazards
  • Maintains the Berkeley Lab NIR Program
  • Develops and reviews substitute or alternate control measures when primary measures are infeasible or impractical
  • With Activity Lead, investigates all instances of suspected exposure

Supervisor/
Activity Lead

 

  • Ensures that all NIR users receive adequate and appropriate training
  • Ensures that all NIR users are assigned to a WPC Activity
  • Prepares an Activity in WPC for an NIR operation and ensures that the provisions of the Activity are properly implemented and diligently followed by users. (To complete an Activity, go to the WPC link on the Berkeley Lab A–Z listing.)
  • Ensures that any visitor receives a site/experimental hazard orientation as part of any visit to any NIR area
  • Investigates all instances of suspected exposure

NIR Equipment Users

  • Receives appropriate on-the-job training (OJT) prior to unsupervised NIR equipment use
  • Reads, understands, signs, and follows all procedures in the WPC Activity
  • Stops unsafe work activities (see PUB-3000, Chapter 1, Work Process C, Stopping Unsafe Work)
  • Works in a safe manner following Laboratory policy and procedural requirements
  • Promptly reports any malfunctions, problems, accidents, or injuries that may have an impact on safety
  • Immediately reports any suspected NIR exposures to the  supervisor and EHS
  • Refers any questions or concerns to the NIR Subject Matter Expert

Important considerations for determining the full extent of safety control measures include:

43.6 Definitions

Term

Definition

Ultraviolet (UV) Radiation

Electromagnetic radiation greater than 10 nm but less than 400 nm

Visible light

Electromagnetic radiation greater than 400 nm but less than 700 nm

Infrared Radiation

Electromagnetic radiation greater than 700 nm but less than 1 mm

Radio Frequency Radiation

Electromagnetic waves greater than 3 kHz but less than 300 GHz

Microwave Radiation

Electromagnetic waves greater than 300 MHz to 300 GHz (within RF frequencies)

NIR

Non-ionizing Radiation (NIR) refers to electromagnetic radiation with insufficient energy to release a bound electron from an atom. NIR includes the following categories of radiation: ultraviolet (UV), visible light, infrared, radio frequency, microwave, magnetic fields, and lasers.

Electromagnetic spectrum

http://bccp.lbl.gov/Academy/wksp_pix_1/spectrum.gif

43.7 Required Work Processes

Work Process A. Non-ionizing Radiation Flowchart
Work Process B. Exposure Limits     
Work Process C. Methods of Exposure Control
Work Process D. Additional Information

Work Process A. Non-ionizing Radiation Flowchart

CH43-NIR-flowchart.png

Work Process B. Exposure Limits

In accordance with 10CFR851, exposures to non-ionizing radiation must be below the limits specified in the 2016 version of Threshold Limit Values for Chemical Substances and Physical Agents, American Conference of Governmental Industrial Hygienists (ACGIH). Because the process to determine the threshold limit value (TLV) is complex and may be adjusted for likely exposure duration, only the most common limits for conditions expected to be encountered at LBNL are listed below. The TLVs for specific applications and exposure conditions may be obtained by contacting the non-ionizing radiation subject matter expert.

Light and Near-Infrared Radiation
TLVs for light and near-infrared radiation apply to incoherent (non-laser) sources of visible and near-infrared radiation. These limits are based on an 8-hour exposure. The TLV is application specific and must be calculated for any broadband light source with a luminance greater than 1 candela/cm2. Contact the non-ionizing radiation subject matter expert to determine the appropriate TLV for light sources with luminance greater than 1 candela/cm2.

Magnetic Fields
The TLVs for magnetic fields are divided into those limits that apply to static (DC) or (CW) magnetic fields and those that apply to sub-radiofrequency magnetic fields or alternating (AC) magnetic fields. The TLV for sub-radiofrequency magnetic fields are frequency specific.

The highest concern is for personnel who have implanted medical devices. Magnetic fields may disrupt the proper function of these devices and have catastrophic effects. This is not limited to cardiac pacemakers, but includes a wide range of devices, such as implantable cardioverter defibrillators (ICDs) and neurostimulators. The TLV in the table below is to be implemented for such devices unless specific higher values are provided in manufacturer-provided documentation.

TLV for Static Magnetic Fields

Exposure

TLV

Medical Device Wearers

5 Gauss (0.5 mT) max

Whole Body (general workplace)

20,000 Gauss (2T) max

Whole Body (special worker training and controlled workplace environment)

80,000 Gauss (8T) max

Limbs

200,000 Gauss (20T) max




TLV for Sub-Radiofrequency Magnetic Fields

 

Frequency Range

TLV

Ceiling / Most Restrictive

Extremely–low-frequency (ELF)

1 Hz to 300 Hz

BTLV (mT) = 60/f
f in Hz

 

 

Hands and feet

1 Hz to 300 Hz

BTLV (mT) = 600/f
f in Hz

2 mT

20 G

Arms and legs

1 Hz to 300 Hz

BTLV (mT) = 300/f
f in Hz

1 mT

10 G

 

60 Hz

 

1 mT

10 G

Whole-body and partial-body

300 Hz to 30 kHz

 

0.2 mT

2 G

 

30 kHz  (160 A/m)

 

0.2 mT

2 G

Medical electronic device wearers

 

 

0.1 mT

1 G

Point contact current

1 Hz to 2.5 kHz

1.0 mA

 

 

Point contact current

2.5 kHz to 30 kHz

0.4·f mA  (f in kHz)

 

 

 

 

 

 

 

 

 

 

 


Radiofrequency and Microwave Radiation
The TLVs for radiofrequency and microwave radiation are dependent on the frequency of the source. Limits apply to all sources from 1 Hz to 300 GHz and often include more than one limiting value, such as electric field strength (V/m), magnetic field strength (A/m), and limits on current induced within the human body (mA).

Part A - Electromagnetic FieldsA (f-frequency in MHz)

Frequency Range

Power
Density, S
(W/m2)

Electric Field Strength,
E (V/m)

Magnetic Field Strength,
H (A/m)

Averaging Time,
E2, H2, or S (minutes)

30 kHz-100 kHz

-

1842

163

6

100 kHz-3 MHz

-

1842

16.3/f

6

1 MHz-30 MHz

-

1842/f

16.3/f

6

30 MHz-100 MHz

-

61.4

16.3/f

6

100 MHz-300 MHz

10

61.4

0.163

6

300 MHz-3 GHz

f/30

 

 

6

3 GHz-30 GHz

100

 

 

34000/f1.079

30 GHz-300 GHz

100

 

 

68/f0.476

 

 

 

 

 

 

 

 



A. Note that in addition to the above electromagnetic field TLVs, induced and contact radiofrequency current TLVs also apply to radiofrequency radiation from 30 kHz to 100 MHz. See the table below for commonly encountered frequencies and their respective limits. The TLVs for specific applications and exposure conditions may be obtained by contacting the non-ionizing radiation subject matter expert.


Part B – Maximum Induced and Contact Radiofrequency Currents
Maximum Current (mA)B, (f-frequency in Hz)

Frequency Range

Through Both Feet

Through Either Foot

GraspingC

Averaging Time

30 kHz-100 kHz

2000 f

1000 f

1000 f

0.2sD

100 kHz-100 MHz

200

100

100

6 minE

B. It should be noted that the current limits given above may not adequately protect against startle reaction and burns caused by transient discharges when contacting an energized object.
The ceiling value for induced and contact currents is 500 mA for no more than 15 s per 6 min period.
C. Maximum touch current is limited to 50% of the maximum grasping current.
D. I is averaged over a 0.2 s period.
E. I is averaged over a 6-minute period (e.g., for either foot or hand contact, i.e., I t<60,000 mA2-min). In this table, f is the frequency in Hz


Ultraviolet (UV) Radiation
The TLVs for UV radiation apply to electromagnetic radiation with a wavelength between 180 nm and 400 nm. Such radiation may present an eye and skin hazard. These TLVs apply to UV radiation from plasma discharges (e.g., welding, plasma etchers, etc.), solar simulators, unfiltered fluorescent and incandescent lights, and other incoherent UV sources. These TLVs do not apply to UV lasers.

The TLVs for UV radiation are wavelength and time dependent. The TLVs listed in the table below are the most restrictive. Contact the non-ionizing radiation subject matter expert for an evaluation of specific UV hazards and determination of specific application TLVs if these limits cannot be met.


Incoherent UV Radiation TLVs

Duration of Exposure Per Day

Effective Irradiance Eeff (mW/cm2)

8 hours

0.0001

4 hours

0.0002

2 hours

0.0004

1 hour

0.0008

30 minutes

0.0017

15 minutes

0.0033

10 minutes

0.005

5 minutes

0.010

1 minutes

0.05

30 seconds

0.1

10 seconds

0.3

1 seconds

3

0.5 seconds

6

0.1 seconds

30

Work Process C. Methods of Exposure Control

Where feasible, engineering controls are used to limit exposure to non-ionizing radiation. Otherwise, administrative controls and personal protective equipment are used.

Work Process D. Additional Information

For assistance with NIR, contact the EHS NIR Safety Coordinator, ext. 2544.

43.8 Source Requirement Documents

43.9 Reference Documents

Document number

Title

Type

07.02.003.001

Work Planning and Control 

Program

07.07.018.001

Laser Safety

Program

 

 

 

 

 

 

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