DRAFT
Contents
Approved by Greta Toncheva
Revised 8/24
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:
🚩🚩 Denotes a new section
🚩 Denotes the beginning of changed text within a section
🛑 Denotes the end of changed text within a section
____________________
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:
- Infrared light
- Magnetic fields
- Microwave radiation
- Radio frequency
- Artificial ultraviolet (UV) radiation
- Visible light
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 ES&H Manual Chapter 16, Laser Safety. )
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 ES&H Manual Chapter 16, Laser Safety.
43.5 Roles and Responsibilities
Role |
Responsibilities |
Division Director |
Ensures the NIR Program is enforced |
Environment, Health & Safety (EHS) Division |
|
Supervisor/ Â |
|
NIR Equipment Users |
|
Important considerations for determining the full extent of safety control measures include:
- Level of experience and training of individuals using the NIR equipment
- Environmental factors
- Personnel factors
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 |
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
Work Process B. Exposure Limits
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 |
NIR Hazard Warning Signs
Areas where employee exposure may exceed the specified limits must be posted with a hazard warning sign including the statement: Radiation in this area may exceed hazard limitations and special precautions are required. Obtain specific instructions before entering.
Examples of warning signs can be downloaded from the NIR web page or provided by the EHS NIR Subject Matter Expert.
Work Process C. Methods of Exposure Control
Engineering Controls
Where feasible, engineering controls are used to limit exposure to non-ionizing radiation. Otherwise, administrative controls and personal protective equipment are used.
- Magnetic Fields. Access must be restricted to only authorized personnel if a person’s whole body would be exposed in an area with magnetic field strength exceeding 5 Gauss. Delineating the 5 Gauss line and posting magnetic field warning signs are generally acceptable access controls.
- RF & Microwave Radiation. Use Faraday cages, cables, or waveguides to contain magnetic fields.
- Ultraviolet Radiation. Shield user by using polycarbonate barriers, polycarbonate safety glasses , long sleeve clothing, gloves, and face shield, as appropriate.
Administrative Controls: Training
All employees using equipment capable of generating hazardous levels of non-ionizing radiation must receive appropriate on-the-job training (OJT) prior to unsupervised equipment use in addition to any existing online training. If in-person OJT is not available, an alternative form of training is to study the manufacturer’s manuals and be familiar with the equipment’s use. The manuals provide specific safety-related information (type of eye/skin protection needed, ventilation requirements, etc.) that must be completely understood before using the equipment.
At a minimum, lab personnel should be familiar with the following when working with or around non-ionizing radiation:
- Proper use of the NIR–generating equipment
- Warning signs and labels
- Proper use of protective equipment provided by the manufacturer (e.g., UV shields/enclosures), as well as PPE
- Health effects and symptoms of exposure
- Information on health effects can be found on the NIR webpage under each hazard.
Work Process D. Additional Information
For assistance with NIR, contact the EHS NIR Subject Matter Expert.
43.8 Source Requirement Documents
- 10 CFR 851, Worker Safety and Health Program
- Cal/OSHA, Title 8, Parts 8617, 8618, 5079, 5085
- C95 IEEE/ANSI Standard on Human Exposure to Radio Frequencies – Threshold Limit Values for Chemical Substances and Physical Agents, American Conference of Governmental Industrial Hygienists (ACGIH), 2016 edition
43.9 Reference Documents
Document number | Title | Type |
07.02.003.001 | Chapter 6 Work Planning and Control | Program |
07.07.018.001 | Chapter 16 Laser Safety | Program |