Safety Advice for Electromagnetic Fields (PDF)
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Safety Advice(PDF)
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Electromagnetic Shielding and Protection

Jump to: Wireless | Power Lines | Nutrition
See also: Precautions | Detection | Nutrition

Where safer alternatives to EMF radiation are not possible, one can try shielding, keeping a distance, as well as nutrition, to reduce the impact of the EMF. Below are some options for shielding and protection for wireless frequencies, radio frequencies, electric fields, and magnetic fields. The effectiveness of shielding should be checked with a meter. (Note: EMFWise is not affiliated with any of the retailers listed below. This information is provided for your convenience.)

Wireless Shielding Options


Shielding by Reflection:Shielding should be done with great care, as improper use could make things worse. The following shielding options work by reflection, so care must be taken to reflect the microwaves in the right direction away from, rather than towards, areas to be protected. Wireless devices like Wi-Fi and cordless phones should be removed from inside the shielding. Sometimes shielding may result in locally increased fields, so great care should be taken not to make things worse. Be cautious before choosing any permanent solution, such as paint, in case it actually makes things worse.

Risk of increasing body voltage: As electric fields are not only reflected by, but also conducted by these materials, it is very important to consider electrical field exposure as well as microwave exposure. It is best to turn off circuit breakers affecting the electrical wiring near shielding projects to avoid increasing your electrical exposure. These wires may be hidden under the flooring or behind the walls.

The need for High dB protection: The material should also be of sufficient protection factor to reduce the penetration of the microwaves through the shield. A protection factor of 20dB (reduction by 100x) is not enough in many cases, and what leaks through may get internally reflected. Note also that gaps in the shield may greatly reduce the effectiveness of the shield. The distance from the shield can also reduce its effectiveness. For example, an analogy has been provided that an umbrella is less effective against rain the further above your head it is.


Silver Tulle fabric can be purchased at with online store Technical Textiles. Search for Tulle 60 dB shielding silver-coated nylon fabric. This fabric can be attached to curtains to reduce the entrance of external radiation into the home. It has some level of transparency, as can be seen from the image at left. Other alternatives which may be worth considering include Argenmesh from Less EMF.

Note: Before creating a canopy for your bed with one of these materials, you may also want to consider how the canopy may potentially affect the electrical field environment around you, e.g., increasing your body voltage. It may be wise therefore to turn off the circuit breakers affecting the electrical fields near such a canopy, and to have it measured afterward both from a wireless and electrical field standpoint. See further electric field options below.

Windows and Window Film

Home Depot and Lowes both offer Gila Heat Control Light Protection Window Film, which can be used on windows to reflect not only heat, but also microwaves. Home Depot, Lowes.

As an alternative to low-E film, if you are replacing windows, you can choose certain energy-efficient windows with low-E coating, which may also reflect microwaves, if they include a special metallized coating, like silver oxide, or internal metallized film. For example, Andersen windows have low-E window glass.

Plastic Lining

ULINE provides Anti-static poly sheeting by the roll ( This is the same plastic enclosing that you may find electronic equipment shipped in.


Shielding Paint from is another solution that several people have reported benefiting from, and supposedly has some absorption ability, rather than operating purely from reflection. However, it may be preferable to use something less permanent in case there is a mistake, resulting in increased electrical field exposure, or in case there is more internal than external radiation. With paint, be extremely cautious because it may be harder to undo, and if it has to be undone, your investment will be lost. Because the shield is conductive, one's electricity exposure must also be considered. In some cases, one may want to experiment with grounding the shield, and adding an insulation layer so that one does not touch the conductive shield.


The best way to solve wireless radiation is to unplug the offending devices, e.g., wireless routers and DECT cordless phones. Alternatively, a timer switch with low intermediate frequencies can be used to at least turn them off at night.

The Cornet meter mentioned on the Detection page can be used to compare different appliances. Further recommendations on technology replacements can be found at the Precautions page.

Other Ideas

Other ideas that have been used for shielding include aluminum mesh screens.

Electric Field Options

Demand Switch

A Demand switch can be used to de-energize plastic Romex-covered wires in the wall and floor, to lower one's electric field exposure and body voltage in sleeping areas. It works by turning on or off the circuit breakers from the circuit breaker panel. A remote button can be used to energize or deenergize key hot and neutral circuits that pass through areas where you spend the most time. For more information, see Safe Living Technologies, Demand Switch.

A cheaper option is to turn off a few circuit breakers affecting the bedroom, and route in a shielded, grounded cable from a different room for electricity.
A more expensive option is to rewire the home with shielded wires. For homes with crawl spaces, it may be possible to change plastic Romex wire to shielded wiring without opening up walls, using an electrician's snake fish tape (snake).

Grounding Electrical Devices

By grounding lamps and other electrical devices like computers, you may be able to reduce some of the interference from these devices. See How to Ground Appliances for instructions on grounding a lamp and computer. Note that using the electrical ground can introduce Intermediate Frequencies as well, so it may be preferrable to use the actual earth for grounding.

Shielding Cables

Shielded cables (labelled on the cable as "SHIELDED") can be used to reduce electrical field exposure. However, they may also result in locally increased Intermediate Frequencies, so distance is required from a shielded cable. See Electric Fields for an explanation of how cables in the walls and floors add to electric field exposure and body voltage.

Avoidance and Distance

To lower one's exposure, it is recommended to make sure sleeping areas are some distance away from unshielded wiring in floors and walls, including both power and ethernet cables. Choose wooden frames over metal frames to avoid bringing the electric field closer to you, and choose non-coil mattresses (e.g., futon or Tempurapedic) over coiled mattresses. New regulations require dangerous flame retardants to be added to mattresses, so special care needs to be made in the choice of a mattress. Helpful guidelines can be found in books such as Green Guide and Prescriptions for a Healthy House. For more guidelines, see Guidelines for Electric Fields.

Intermediate Frequencies Options

Aluminum Foil

Aluminum foil can be used to create a Faraday cage around electronics to block intermediate frequencies. For example, if you were to completely wrap a radio, you can block radio signals from reaching it with sufficient layering of aluminum foil. Note, however, that while you could wrap your computer mouse also with aluminum foil, when you touch the conductive aluminum foil, the signal may actually be amplified and become worse. Use with caution. Care must also be used in the presence of electric fields as previously discussed, since aluminum foil can conduct electricity. Similarly, as aluminum foil is dangerous in a microwave oven, perhaps there are occasions where you would not use it in a wireless environments.

Unplug or replace

The best way to solve Intermediate Frequencies is to replace devices with high Intermediate Frequencies with devices with no or low Intermediate Frequencies. For example, replace dimmer switches with regular dipole on-off switches, and CFL light bulbs with incandescent light bulbs. Replace plasma TV's with LCD Tv's.

The Grundig G8 meter mentioned on the Detection page can be used to compare different appliances. Further recommendations on technology replacements can be found at the Precautions page.


If replacement is not an option, distance is the best protection. For example, see Safe Computing for recommended distances from your computer.

Powerline AC Magnetic Field Shielding Options

Fix Wiring Errors

In some cases, fixing wiring errors can reduce magnetic field problems. Please see the following video for more information. For more information, consult Powerwatch UK's "House Wiring and EMFs" paper or Karl Riley's resource, TRACING EMFs in Building Wiring and Grounding. For the troubleshooting process, Karl Riley recommends using an AC/DC clamp meter and a gaussmeter.

MuMetal Foil

Not all metals will work for magnetic field shielding. You need a metal with a high permeability rating, such as mu-metal. Some options which have been recommended include nickel alloys and low carbon steel.
Note that such shielding can be very difficult, however, as you are essentially redirecting the magnetic fields. You need to almost completely enclose the source, but this is not always possible, and can be very expensive. Hence, the ideal is to either fix the source of the problem, such as wiring error, or to keep enough distance from the source.

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