Magnetic fields safety program

Microsoft establishes the Magnetic Fields Safety Program for compliance with applicable regulations such as OSHA 29 CFR 1910.97, Nonionizing Radiation.  Additional state and local regulations may also apply.  The program also includes guidelines established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) of the International Radiation Protection Association (IRPA).

This program is applicable to the Microsoft employees and external staff working in areas where Magnetic Fields (MF) are present.  The program includes specific guidance pertaining to MF within the static, extremely low frequency (ELF), microwave, and radio frequency (RF) fields, and provides information on the possible hazards of MF and guidance for maintaining a safe work environment.  This document is not to be construed as a synopsis of all MF requirements.  

1.1 Exceptions  

This program does not apply to other types of non-ionizing radiation such as lasers, ultraviolet light, visible light, and non-ionizing radiation produced during operation of conventional microwave ovens.     

The ICNIRP guidelines referenced in this program may not necessarily cover interference with or effects on biomedical devices.  Interference with pacemakers may occur at levels below ICNIRP’s recommended reference exposure levels.  Advice on avoiding these problems is beyond the scope of this program.  

2.1 Prevention and Control  

2.0.1 Written Magnetic Fields Control Plan  

Each Microsoft facility utilizing equipment with the potential to produce harmful levels of magnetic fields (MF) must develop a Site Magnetic Fields Plan (Site Plan).  The Site Plan must be made available to any personnel affected by this procedure (i.e., employees, external staff, and regulatory agency personnel).  The Site Plan must include the following:  

• Program purpose and scope. 

• Site-specific regulatory requirements. 

• Personnel roles and responsibilities. 

  • A Site Administrator must be identified for each work area for implementation and oversight of the Site Plan. 

• Definitions of terms critical to an understanding of the Site Plan, or those terms not commonly understood, including the definitions.

• PPE requirements.   

• MF Procedures 

  • General safety rules. 

  • Dosimetry requirements. 

• Site-specific training and emergency response procedures: 

  • Documentation of First Aid/CPR trained employees. 

  • Training on response actions related to a harmful or uncontrolled exposure to levels of MF. 

  • Locations of emergency disconnect devices.   

• Inspection documents. 

• Incident investigations for all accidents, incidents, and near-misses that were directly or indirectly related to MF.  

2.0.2 Risk Assessment

The Plan Administrator, in conjunction with Microsoft OHS, will assess the workplace to develop a current listing of the devices which emit MF.   

• The assessment will result in a listing of hazard areas, activities, or processes to assure that the appropriate area classifications have been identified./p>

• Assessments must be reviewed and amended as necessary when processes, equipment or facilities create or change the risks and hazards associated with these devices.

• The analysis will define specific hazards associated with MF and create a plan for hazard mitigation and employee training.  

For equipment designed or assembled at Microsoft, Microsoft OHS must be included in all phases of the design process.  Microsoft OHS will assist in predicting exposure levels and developing protective measures included as an integral part of the design.  The goal will be to limit or minimize the MF emissions of the equipment. 

Employees and external staff may be exposed to high MF if they work near electrical systems that use large amounts of electric power (for example, large electric motors, generators, or the power supply or electric cables of a building). The strength of the MF depends on equipment design and current flow and not on equipment size, complexity, or voltage.  The following are examples of MF sources that may be present at Microsoft:  

• DC electric power transmission lines and distribution panels.   

• AC electric power transmission lines and distribution panels. 

• Transformer substations. 

• Cable lines. 

• Cellular Phone Towers. 

• Electric power supply system of 0.4 kV. 

• TV stations. 

• Earth-to-space satellite radio communications stations. 

• Test sites of radio technical equipment. 

• Industrial electric equipment and technological processes: machine tools, induction funnels, welding equipment, cathode protection stations, electrotype, dielectric material dryers, etc. 

• Electric transport and their infrastructure. 

• Product testing chambers. 

• Satellite Dishes. 

• Power Lines and Substations.

• Server Rooms

2.0.3 Health Effects

Current scientific information does not indicate any serious health effects resulting from the acute exposure to static MF up to 8 T, which is the magnetic strength of typical magnetic resonance imaging (MRI) equipment.  However, such exposures can lead to unpleasant sensory effects such as vertigo and a temporary reduction in the quality of some behavioral tasks during head or body movement.

Most documented health effects for RF exposure are short-term and reversible.  The effects primarily relate to the direct heating of tissues or the flow of current through tissue.  Health effects observed in humans from RF fields include the formation of cataracts, induction burns, and burns from contact with metal implants.

2.0.4 Special Populations 

If planning a pregnancy, employees with exposures to MF, should seek advice from a primary licensed health care provider (PLHCP). If an employee becomes pregnant, they are strongly encouraged to declare their pregnancy in writing to the Microsoft OHS. The allowed dose for the pregnant employee must remain ALARA for the duration of pregnancy.

Persons with biomedical devices should consult their PLHCPs and their Microsoft Human Resources Business Benefits Partner to discuss any concerns about magnetic fields in the workplace.

2.1 Dosimetry and Occupational Exposure Limits  

ACGIH has recommended a ceiling of 0.5 mT for persons with electronic medical devices and a TLV of 2 T for normal populations. 

The ICNIRP reference levels for occupational exposures to static, ELF, and microwave/RF fields are included in Appendix B.  

Dosimetry will be conducted for employees who may be exposed to 2 T or more of MF radiation.  

For more information on exposure assessments, please reference the Exposure Assessment Program. 

2.2 Sources  

MFs are produced by a variety of sources that use electricity. The most common sources of MF that could be found in the workplace are listed below. 

2.2.1 Static MF  

Static MF results from either fixed magnets or the magnetic flux resulting from the flow of DC. Sources producing these fields include but are not limited to Helmholtz coils, solenoids, and DC motors. Factors affecting potential hazards include:

• Magnetic flux intensity associated with the source. 

• Design of the MF source. 

• Accessibility of the MF. 

• Equipment/hazardous materials associated with the MF source.  

2.2.2 ELF

ELF field intensity is a function of amperage passing through the wiring. In general, mechanical spaces, machine shops, transformers, and large motors will produce the most intense ELF fields.  Laboratories and offices usually do not have intense ELF fields and a reasonable average value for these areas has been measured at about 3 to 5 mG.  

2.2.3 Microwave and RF 

Potential sources of microwave/RF radiation that exist at Microsoft include:    

• Antennas 

• Co-axial cables 

• Waveguides 

• Transmission generators   

• Power supplies   

• Power lines   

2.3 Leakage of Microwave and RF Radiation

Leaking microwave and RF sources will normally occur due to misalignment of doors or plates, missing bolts, or physical damage to plane surfaces.  Equipment that supplies high voltage power also operates in the microwave or RF frequencies.  If damaged or not properly shielded, these sources can leak and produce unintended exposure. 

• One of the most important aspects of controlling microwave and RF radiation hazards is a careful physical inspection of their potential source.   

• Potential sources that show signs of physical damage should be repaired and then surveyed with appropriate instrumentation to verify the problem has been addressed.    

If microwave/RF radiation leakage is suspected, (RF interference with other equipment or medical devices), contact  Global OHS immediately for a workplace survey. 

2.4 Controls 

There are many controls that personnel can take to decrease their exposure to MFs. The three basic controls (time, distance, shielding) are discussed below.  

2.4.1 Time  

Minimize the time spent in areas where high MF are present. The dose-related exposure occurs as a function of duration of exposure.  The less time spent in high MF areas, the lower the exposure. Reducing the time required for operation and maintenance of equipment that produces MF can be achieved in a number of ways.   

• Training – knowledge on how to work with MF sources properly and safely.   

• Planning – having all the proper tools and equipment ready ahead of time. 

• Dry runs – practice all of the steps that will be followed before the actual work begins.  

2.4.2 Distance  

Maximize the distance from sources of high MF. Dose is inversely proportional to distance, therefore, greater distance means less dose. 

2.4.3 Shielding 

Use shielding wherever it is necessary to reduce or eliminate exposure.   

• By placing an appropriate shield between the MF source and the worker, exposure may be completely eliminated or reduced to an acceptable level.   

The type and amount of shielding needed to achieve a safe working level varies with the type and quantity of radioactive source used.   

2.4.4 Personal Protective Equipment  

PPE requirements will be specified in the Standard Operating Procedure for use of a specific piece of equipment and based on an exposure assessment. PPE specific to protection from MF may be required for exposures greater than 8 T. For more information reference the Microsoft Personal Protective Equipment Program and the Microsoft Exposure Assessment Program. 

2.4.5 Control of Hazardous Energy 

Only qualified professionals can perform maintenance activities on MF emitting equipment and must control energy when working on such equipment in accordance with the Microsoft Hazardous Energy Control Lockout Tagout (LOTO) Program.  

2.5 Signage and Labels 

Signage is required to inform workers of the area’s radiological conditions, and to inform workers of the entry requirements for the area.   

• In order to maintain exposure to radiation at ALARA, restrict personnel access to areas or devices where MF exceeds the OEL.   

• The FCC requires areas surrounding broadcast antennas to be posted and fenced or otherwise restricted, if the ambient RF fields exceed the reference levels for unrestricted occupancy by the public.  

All areas that must be restricted due to potential RF exposure must be posted with a sign to warn personnel of the risk inside the restricted area.  The sign must be a warning symbol consisting of a red triangle above an inverted black triangle, separated and outlined by an aluminum color border. The words "Warning - Radio-Frequency Radiation Hazard" must appear in the upper triangle. 

Refer to Appendix C for more examples of signage requirements.

• Postings and barriers must be clearly visible from all accessible directions.  

• Postings on doors should remain visible when doors are open or closed.  

• Postings should state the entry requirements.  

• If more than one radiological hazard exists in an area, the posting should identify each hazard.  

• Postings that indicate an intermittent radiological condition should include a statement specifying when the condition exists such as when a red light is “on.”   

The control panel of an intentional MF generating device must be labeled with the words:  

A device that fails to meet all appropriate safety requirements must be disabled and display a red warning label indicating that the device must not be used. 

2.6 Emergency Procedures 

If there is reason to suspect an uncontrolled MF, the operator of the device should turn off the equipment, evacuate the area, and notify Microsoft OHS.  Microsoft OHS will inform the Plan Administrator and Lab/Facility Manager when it is safe to return to the area.  

2.7 Inspection  

Annual inspections will be performed in high risk areas where it is possible employees could exceed the OEL. These inspections will be conducted with oversight from the Plan Administrator and Microsoft OHS.   

2.8 Training 

Each location must train employees on MF hazards present in the workplace and specifically with their job.  Training will be provided at initial assignment.  Employees must be retrained if changes in procedures or work assignments occur.  Microsoft has defined training to meet regulatory requirements for MF.  To obtain training, contact Global OHS. 

The training program must include the following information:  

• An overview of working near MF and hands-on instruction of the applicable Site Plan. 

• Applicable federal, state, or local regulations. 

• Summary of the MF program and how to access the written program. 

• Procedures for responding to and reporting an incident. 

• Instruction on how employees can request a risk assessment to determine if hazards are present.  

Incident investigations are initiatied upon receiving reports. To foster a culture of health and safety at Microsoft, employees, interns, and external staff are required to report all work-related accidents, injuries, and illnesses via SafetyHub Report. Learn more on the Global OHS reporting page.

Copies of this document will be maintained online at the Microsoft intranet.  Employees have continuous access to this document.  

4.1 MF Records  

When MF emitting equipment is installed and commissioned, all data should be stored and made available for any engineer or person who may subsequently be required to work on the system.    

4.2 Dosimetry Records  

All dosimetry records are maintained by Microsoft OHS. Upon request, employees will be supplied with their personal dosimetry history.  Each year, employees will receive an annual written summary of their radiation exposure, even if the exposure has been zero for the entire year.  Terminating personnel can request a report of the radiation dose received at Microsoft. Notify Microsoft OHS of any radiation dose received at another facility so that dose records can be updated.

4.3 Other Records  

At Microsoft, data and documents are retained in compliance with the retention times set out in our Corporate Retention Schedule.

In addition to those listed above, each site must maintain the following records and have them available for review by Microsoft OHS.   

The following terms are used in this document.  The definitions below are used in the scope of this document, but local regulatory definitions supersede if there is a conflict.

Absorption: The attenuation of a radio wave due to dissipation of its energy, i.e., conversion of its energy into another form, such as heat.

American Conference of Governmental Industrial Hygienists (ACGIH): a member-based organization that advances occupational and environmental health.  

American National Standards Institute (ANSI): An institute that oversees the creation, promulgation and use of thousands of guidelines and standards that directly impact businesses through quality and assessing conformance to standards.  

As Low As Reasonably Achievable (ALARA): Making every reasonable effort to maintain exposures to radiation as far below the dose limits as practical, taking into account the state of technology, the economics of improvements in relation to benefits to health and safety, and other societal and socioeconomic considerations.  

Basic Restrictions: Mandatory limitations on the quantities that closely match all known biophysical interaction mechanisms with tissue that may lead to adverse health effects.  

Direct Current (DC): An electric current of constant direction, having a magnitude that does not vary or varies only slightly. 

Dosimeter: A device used to measure an individual’s exposure to a hazard found in the environment.  

Electric and Magnetic Field(s) (MF): Invisible lines of energy that surround any electrical device and are produced through the generation, transmission, and use of electric power.  Voltage produces an electric field and current produces a MF. 

Electronvolt (eV): The amount of energy gained by the charge of a single electron moved across an electric potential difference of one volt  

Engineering Controls: The elimination or reduction of a hazard by means of engineered machinery or equipment. Examples include process change, isolation, ventilation, and source modification.  

Extremely Low Frequency (ELF): frequency below 300 Hz. In the ELF range, electric and MF act independently, unlike electromagnetic fields of higher frequencies.  These types of fields can be generated naturally and by artificial sources like electrical transmission lines.  

Federal Communications Commission (FCC): Regulates interstate and international communications by radio, television, wire, satellite, and cable in the United States, including the District of Columbia and U.S. territories. It was established by the Communications Act of 1934 and operates as an independent U.S. government agency overseen by Congress.

Frequency: The number of cycles completed by an electromagnetic wave in 1 second; usually expressed in hertz (Hz). Electricity in North America alternates through 60 cycles per second, or 60 Hz. In many other parts of the world, the frequency of electric power is 50 Hz.  

Gauss (G): unit of magnetic induction in the centimeter-gram-second system of physical units.  

One gauss corresponds to 10-4 tesla (T), the International System Unit.  

Hertz (Hz): The unit for expressing frequency, (f). One hertz equals one cycle per second. 1 kilohertz (kHz) = 1,000 Hz, 1 megahertz (MHz) = 1,000 kHz, 1 gigahertz (GHz) = 1,000 MHz.  

Institute of Electrical and Electronics Engineers (IEEE): The world’s largest professional association dedicated to advancing technological innovation and excellence for the benefit of humanity.  

International Agency for Research on Cancer (IARC): An intergovernmental agency of the United Nations whose role it is to conduct and coordinate research into the causes of cancer.  

International Commission on Non-Ionizing Radiation Protection (ICNIRP): A body of independent scientific experts consisting of a main Commission of 14 members, 4 Scientific Standing Committees covering Epidemiology, Biology, Dosimetry and Optical Radiation and a number of consulting experts.  This expertise is brought to bear on addressing the important issues of possible adverse effects on human health of exposure to non-ionizing radiation.   

International Radiation Protection Association (IRPA):  An international professional association for radiation protection. It promotes excellence in the practice of radiation protection through national and regional Associate Societies and radiation protection professionals by providing benchmarks of good practice and enhancing professional competence and networking.  

Kilovolts (KV): A unit of electromotive force equal to 1,000 volts.  

Magnetic Field Strength: An axial vector quantity, H, which, together with magnetic flux density, specifies a MF at any point in space, and is expressed in ampere per meter (A m-1).  

Magnetic Flux Density: A vector field quantity, B, which results in a force which acts on a moving charge or charges and is expressed in tesla (T).  

Microwaves: Electromagnetic radiation of sufficiently short wavelength for which practical use can be made of waveguide and associated cavity techniques in its transmission and reception. The term is taken to signify radiations or fields having a frequency range of 300 MHz to 300 GHz.  

MilliGauss (mG): A unit of magnetic induction equal to 1/1,000 G.  

Non-ionizing Radiation (NIR): Includes all radiations and fields of the electromagnetic spectrum that do not normally have sufficient energy to produce ionization in matter; characterized by energy per photon less than about 12 eV, wavelengths greater than 100 nanometers (nm), and frequencies lower than 3 x 1015 Hz.  

Occupational Exposure Limit (OEL): A health-based workplace standard to protect workers from adverse exposure.  

Radiofrequency (RF) Energy: Any frequency at which electromagnetic radiation is useful for telecommunication.  RF refers to the frequency range 300 Hz to 300 GHz.    

Reference Levels: The root mean square, peak electric and MF, and contact currents to which a person may be exposed without adverse effects and with acceptable safety factors. The reference levels for electric and MF exposure in the ICNIRP guidance may be exceeded if it can be demonstrated that the basic restrictions are not exceeded. Thus, it is practical or “surrogate” parameters that may be used for determining compliance with the Basic Restrictions.  

Restricted Area: Any area access which is controlled by the employer to protect individuals from exposure to a hazard. 

Static Magnetic Field: A field that does not vary with time. This type of magnetic field is generated by a magnet or by the flow of direct current (DC).  

Tesla (T):  The International System Unit of magnetic flux density. 1 tesla = 10,000 gauss.  

Threshold Limit Value (TLV): Occupational exposure levels established by the ACGIH.  The value is established at an exposure level where nearly all workers may be exposed without adverse health effects. 

Unrestricted Area: Any area access which is not controlled by the employer to protect individuals from exposure to radiation or radioactive materials. 

Volt (V): The International System Unit derived unit for electric potential, electric potential difference, and electromotive force. 1 kilovolt (kV) = 1,000 V  

World Health Organization (WHO): The directing and coordinating authority for health within the United Nations system. It is responsible for providing leadership on global health matters, shaping the health research agenda, setting norms and standards, articulating evidence-based policy options, providing technical support to countries and monitoring and assessing health trends.  

7.1  Microsoft Internal 

• MS Policy 37019-2, Regulatory Compliance 

• MS Policy 37019-5, Regulatory Investigations, Inspections, and Inquiries 

• Medical Surveillance Procedure 

• Microsoft Accident Prevention Program

• Microsoft Vendor Code of Conduct

• Microsoft Exposure Assessment Program

• Employee Safety Incident Reporting and Investigation Procedure

• Microsoft Hazardous Energy Control (Lock-Out/Tag-Out) Program

• Microsoft Personal Protective Equipment Program     

7.2 Microsoft External

• OSHA, 29 CFR 1910.97, Nonionizing Radiation. 

• Federal Communications Commission (FCC), Office of Engineering and Technology, Questions and Answers about Biological Effects and Potential Hazards of Radiofrequency Electromagnetic Fields 

• Institute of Electronics and Electrical Engineers (IEEE), C95.1-2005, Standard for 

• Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields (3 KHz-300 GHz)  

• Institute of Electronics and Electrical Engineers (IEEE), C95.6-2002, Standard for Safety Levels with Respect to Human Exposure to Electromagnetic Fields, 0 to 3 kHz. 

• American Conference of Governmental Industrial Hygienists (ACGIH), Documentation of the Threshold Limit Values for Physical Agents, 7th Ed.  

• National Institute of Occupational Safety and Health (NIOSH), Health Hazard Evaluation Report, HETA 2008-0286-3084 May 2009, Evaluation of Cancer and Magnetic Fields in an Office. 

• International Commission on Non-ionizing Radiation Protection, ICNIRP Guidelines on Limits of Exposure to Static Magnetic Fields  

• International Commission on Non-ionizing Radiation Protection, ICNIRP Guidelines for Limiting Exposure to Time-Varying Electric and Magnetic Fields (1 Hz to 100 kHz) 

• International Commission on Non-ionizing Radiation Protection, ICNIRP Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic, and Electromagnetic Fields (Up to 300 GHz)  

• Washington, WAC 296-62-09005, Nonionizing Radiation. 

• California, CCR, Title 8, Section 5085, Subchapter 7, Group 14, Article 104, Radiofrequency and Microwave Radiation   

The Plan Administrator may use this outline to produce a written Magnetic Fields Site Plan for machines, equipment or processes under their control.  The Site Plan must be tailored to identify or comply with the following:  

• Federal, state, or local regulations governing MF at the facility location

• Machines, equipment, or processes covered under their program

• Employees or external staff covered under their program.  

Managers must make the written plan available to employees, external staff, and corporate or regulatory compliance officers. 

Purpose  

State the purpose of the program (ensure that personnel interact with MF in a safe manner and within their training and authority).  

Scope 

Describe the area or facility-specific operations that fall under this program (new and existing MF emitting equipment).  

Regulations

A list of any applicable federal, state and local regulations must be included here.  For example, in the United States, federal regulations for non-ionizing radiation (NIR) safety fall under OSHA 29 CFR 1910.97 “Nonionizing Radiation”, IEEE’s C95.1 and C95.6 “Standards for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields”, and the FCC’s OET 65 Standard “Questions and Answers about Biological Effects and Potential Hazards of Radiofrequency Electromagnetic Fields”.  Individual states or local municipalities may have additional requirements.

Roles and Responsibilities

Personnel with responsibility for oversight or implementation of MF safety must be identified here.  This list should include the names of specific individuals, job titles, applicable licenses or certifications, and a summary of their roles and areas of responsibility.

Definitions  

The written Site Plan must include definitions.  Included here is a list of definitions commonly referred to in an MF safety plan.  Additional definitions may be required based on applicable regulations or activities that take place at the site.   

Workplace Survey and Risk Assessment  

Summarize the workplace survey and hazard results at the workplace.  This summary can be presented as a table for easy reference.  Be sure that the summary allows the reader to easily identify the referenced machine, equipment, or process on the workplace floor.  This can be done by including photographs or floor maps in the document. 

MF Procedures

This section must include the rules or requirements for MF safety program implementation.  This section must describe step-by-step procedures to mitigate MF hazards before entering a restricted area and special circumstances. 

Examples of items that need to be outlined in this section include:  

1. Types and locations of MF emitting equipment that may exceed the OEL. 
2. Dosimetry instructions and schedule. 
3. Engineering and administrative controls that are in place to reduce exposure to MF. Include controls for which there is a plan to add them in the future. 
4. PPE requirements. 
5. Safe work practices (safe work rules and MF safety considerations) to support the development of safe working habits. 
6. General safety rules. 
7. Site specific training on emergency response procedures. 
8. Inspection records for MF emitting systems located on site. 
9. Completed Risk Assessments. 
10. Procedures for notifying employees working around MF emitting devices to inform them of their risk and exposure.  

Training

Information on training frequency and site-specific training content and emergency response procedures must be incorporated in this section. 

Audits 

Annual audits of each established Site Plan must be performed to assess the effectiveness.  Audit documentation must be retained onsite.  Following the audit, training and other corrective actions must be taken as necessary.  

Incident Investigations  

Documentation will be performed of incident investigations for all accidents, incidents, and near misses that were directly or indirectly related to magnetic fields. Incidents inspection must be conducted by trained investigators following defined investigation methodology. Findings from the investigation should summarize the key points and corrective actions those incidents that were directly or indirectly related to MF exposure.

Limits of exposure to static magnetic fields (source: Table 2 of ICNIRP’s Guidelines on Limits of Exposure to Static Magnetic Fields)  

Reference levels for occupational exposure to time-varying electric and ELF magnetic fields  

(source: Table 3 of ICNIRP’s Guidelines for Limiting Exposure to Time-Varying Electric and Magnetic Fields [1 Hz to 100 kHz])

Reference levels for occupational exposure to time-varying electric and microwave/RF magnetic fields (source: Table 6 of ICNIRP’s Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic and Electromagnetic Fields [up to 300 GHz])  

Radiofrequency warning or "alerting" signs should be used to provide information on the presence of RF radiation or to control exposure within a given area.  Guidance concerning the placement of signs can be found in IEEE Standard C95.7-2005.  Signs should be located prominently in areas that will be readily seen by those persons who may have access to an area where high RF fields are present.