Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

Magnetic field matsDate:

19 October 2016

Magnet field mats are used in medicine for therapeutic treatments of various disorders. For private use
these mats are also used as recreational and wellness equipment so as to increase for example general wellness or to help the body to recover more quickly after sporting activities.
The strong magnetic fields generated by the magnetic field mats exceed in some cases the international recommended limit values. Consequently, health risks cannot be unequivocally ruled out for longterm use. Also, according to the present state of knowledge, the health benefit associated with thesemats has not been proven.
People who use the magnetic field mats should therefore respect the following precautionary measures:








Do not use magnetic field mats for recreational and wellness purposes.
Children and pregnant women should not use magnetic field mats .
Persons with a pacemaker or another electronic medicinal implant should not use magnetic fieldmats , as this could lead to a malfunction of the implant.
Make sure that you follow closely the manufacturer’s instructions in regard to the lying position andposition yourself on the mats as indicated in the instruction manual.
The efficacy of these mats has not been scientifically proven.
The costs of the magnetic field mats are not reimbursed by the health insurance companies.

Bundesamt für Gesundheit BAG
Schwarzenburgstrasse 157, CH-3003 Bern

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

1 Purpose of magnetic field mats
1.1 Design and Operation
Magnetic field mats are available in various sizes. This depends on whether they are designed fortreating the whole body or for individual areas of the body. Both the whole body and partial body matscontain coils, through which flow the pulsed low frequency electric currents. These currents generatemagnetic fields that permeate the body of the treated person. These magnetic fields again generate
electric currents in the electrically conductive body of the person and if sufficiently intense can provoke
physiological effects.
Signal form, frequency, magnetic field strength and coil arrangement differ depending on the manufacturer of the mats. The coils are either spiral in shape (Figure 1, mats 1 and 3) or are formed by a plurality of pairs of coils of differing power (Figure 1, mat 2).

Figure 1: Arrangement of the coils of three different magnetic mattress pads.

1.2 Purpose
Therapeutic magnetic field mats are recommended by the manufacturers for the treatment of various
disorders such as arthritis, rheumatism, headaches, asthma or osteoporosis. According to the manufacturers, these mattresses can also be used as recreational and wellness equipment so as to increase general wellness or to help the body to recover more quickly after sporting activities. Magnetic
field mats are sold or rented for home use as well as for use under medical or therapeutic supervision.

1.3 Applications
Magnetic field mats generally offer a number of application programmes that differ in intensity and duration and are recommended for different symptoms or medical conditions.

Bundesamt für Gesundheit BAG
19 October 2016

Seite 2 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

Magnetic field mats are designed in such a way that the person being treated lies directly on the mator the mat is positioned during use under the bed mattress. The length of the treatment can be between 15 minutes and several hours.

2 General risks and benefits of magnetic field mats
The magnetic field mats available on the Swiss market in 2012 were declared by the manufacturers as
medical devices pursuant to the ordinance on medical devices (MepV, SR 812.213). Consequently,
the manufacturers have to manufacture them in accordance with the applicable regulations and standards, and prove a medical benefit or a therapeutic effect. In addition, the products have to be designed
and manufactured such that their use under the intended conditions and for the intended purposes
neither endangers the clinical state and safety of the patients nor the safety and health of the user orof third parties. An assessment process exists for medical devices. This assessment process is carriedout by a notified body that delivers a CE mark and a four digit number for tested products.
Medical devices do not necessarily have to respect the conventional international limit value recommendations that for example apply to domestic appliances. The reason for this is that the benefits andrisks associated with medical devices are to be weighed. Limit values may then be exceeded if thetreatment has a corresponding benefit, and the consequences of exceeding the limit value are smaller
than the benefits of the treatment.
The medical device Ordinance is not applicable to devices without medicinal purposes, such as for example for cosmetic purposes or wellness applications. The safety of these devices is regulated inother provisions (Ordinance on electric low voltage products as well as the product safety law and ordinance).
The Federal Office of Public Health (FOPH) commissioned various studies in order to assess both thebenefits (chapter a. Effectiveness and Benefits of Magnetic Mattress Pads) as well as the risks (chapter b. Risk Assessment of Magnetic Mattress Pads) of Magnetic Mattress Pads.

2.1 Literature Study on Effectiveness and Benefits of Magnetic Field
Mats
MethodThe Swiss Tropical and Public Health Institute (Swiss TPH) was mandated by the FOPH to carry out aliterature study on the therapeutic effects of magnetic field mats. This review of the literature solely included randomised double blind studies. This study type involves part of the participants in the study
being treated with magnetic field mats that were switched on (the intervention group), the other part,however, with mattresses that were switched off (the placebo group). Allocation to both groups was
randomised. Neither the participants in the study nor those conducting the tests knew who was being
treated with magnetic fields and who was not. The review took into account only peer-reviewed studies that were published up to the end of March 2010 in a scientific journal.

Bundesamt für Gesundheit BAG
19 October 2016

Seite 3 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

The systematic literature search in various scientific databanks found a total of 155 publications on theuse of electrotherapeutic methods. Thirteen of these studies related to the use of magnetic field matsand met the above described criteria. In most of the other studies, smaller devices for magnetic uses
on individual areas of the body, or other electrotherapy methods were investigated. As one of the studies on the use of magnetic mattress pads had been published twice, a total of twelve publications
were evaluated.

Results
In the twelve studies the use of whole body magnetic field mats was investigated for the following
symptoms:









arthritis of the knee (3 studies)arthritis in the area of cervical vertebra (1 study)
fibromyalgia (widespread muscular pain) (1 study)
perception of pain (2 studies)
Heart rate variability in healthy persons (1 study)
wound healing and microcirculation (2 studies)chronic fatigue in persons suffering from multiple sclerosis (2 studies)

The four studies on arthritis of the knee or cervical vertebra produced conflicting results in regard topain reduction. Three studies indicated a decrease in pain, but only one study included a subsequent
control after four weeks. At this point in time a treatment effect was no longer detectable. In regard to
the desired improvement of the functionality of the joint, the results were not uniform and showed individual effects that, however, were not identical in all studies.
The single study on fibromyalgia patients pointed to a decrease of the impairments due to the disease
and to the level of pain after three weeks of using a magnetic mattress pad. The subsequent control
after twelve weeks demonstrated only slight improvements.
In both studies relating to pain perception, no difference was observed between treated and untreatedpersons.
Only twelve patients participated in each of the two studies on wound healing and microcirculation.
There were no differences between those who had used the magnetic mattress pads and those who
had not been exposed to magnetic fields.
The results of the studies on fatigue in patients suffering from multiple sclerosis were not consistent
either: In one of the two studies an improvement was observed after twelve weeks’ use of magnetic
mattress pads, in the other investigation, however, the persons of the intervention group were lesstired than those not exposed to magnetic fields only immediately after each use of the magnetic mattress pad.
The study of the heart rate variability showed overall no changes by the use of magnetic field mats.

Bundesamt für Gesundheit BAG
19 October 2016

Seite 4 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

The results of the 12 studies are again summarised in Table 1.

Table 1: Overview of the results of the 12 evaluated studies of the systematic literature search
Results

Clinical picture

numberof studies

numberof paticipants

Arthritis of the knee

3158

No significant and lasting
effects

Arthritis in cervicalvertebrae

1

32

No lasting effects

Fibromyalgia

156

Positive effects

no effects

Indications of short-term improvements in regard topain and impairment

Pain perception

2100

No difference between
treated and untreated persons

Heart rate variability

127

No changes

wound healing andmicrocirculation

2

24

No improvement

Fatigue in MS patients

Bundesamt für Gesundheit BAG
19 October 201637

Study 1: no immediate imStudy 1: improvement in faprovement and none aftertigue after 12 weeks
6 weeks

24

Study 2: improvement in fa- Study 2: no lasting improtigue immediately after use vement

2

Seite 5 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

In summary, these studies do not show any compelling evidence for the value and efficacy of magnetic field mats.

Reimbursement by the health insurers
Swiss health insurers do not reimburse the costs of magnetic field mats. The legal bases for the reimbursement of products and devices as a standard cover of the health insurance are governed by thelaw on health insurance (KGV; SR 832.10). The Health Care Benefits Ordinance (KLV; SR
832.112.31) that is based on this law has a list of products and devices that may be covered by the
obligatory health care insurance. Magnetic field mats are not in this list.

2.2 Risk assessment for the use of magnetic field mats
Limit values for magnetic fields
The "International Commission on Non-Ionizing Radiation Protection" (ICNIRP) is a scientific commission recognised by the World Health Organisation WHO and the European Union. It assesses the impact of electromagnetic fields on health and delivers recommendations for limit values. The ICNIRP
recommended limit values form part of the fundamental requirements for the safety of electrical products in Europe. Although magnetic mattress pads, as medical devices, do not have to meet these limit
values, their risk potential is nonetheless gauged using these limit values. This is particularly so, as
the above described literature study shows that no benefit is to be expected.
These limit values are based on scientifically proven acute effects that occur with humans when their
exposure to electrical or magnetic fields exceeds a certain level. The limit values for allowable exposure of the general population for low frequency fields are 50 times lower than this value. Acute effects
of very strong low frequency magnetic fields can affect both the central as well as the peripheral nervous systems. The central nervous system includes the brain and the spinal cord. The peripheral
nerves include the cranial nerves, nerves in the wall of internal organs and all nerves that emanatefrom the spinal cord to other parts of the body.
The ICNIRP fundamentally differentiates two categories of limit values: basic restrictions and derived
reference levels. The basic restriction in the low frequency region is related to electric currents that are
generated in a body (body currents) by exposure to a magnetic field and which produce acute effects
on the functions of the nervous system. However, as these body currents cannot be directly measured, the derived reference levels tend to be used in practice because they can be measured as theelectrical or magnetic field without the person being present. If these magnetic field reference levels
are respected then the current in the body of an exposed person is mostly below the basic restriction.
If, however, the reference level is exceeded, then compliance with the basic restriction must be
checked. This is possible with inter alia complex computer simulations.
The limit value recommendations do not take account of potential long-term effects, as the ICNIRP
has rated the proof for damaging effects of long-term exposure to weak electromagnetic fields as inadequate.

Bundesamt für Gesundheit BAG
19 October 2016

Seite 6 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

General effects of magnetic fields on healthStrong low frequency magnetic fields can provoke unwanted neural stimuli and muscle contractions
and thereby cause malfunctions, such as e.g. muscle cramps. The ICNIRP recommended limits permit
magnetic fields to be only so great that the electrical currents produced in the body are at least a factor of 50 below the excitation threshold.
In our environment, for example in the proximity of high voltage lines or other current carriers, magnetic fields are produced that are far below the limit values recommended by the ICNIRP. Some epidemiological studies have shown an increased risk of leukaemia in children due to these weak but
long term magnetic field exposure (<0.4 μT (microtesla)) from high voltage lines (illustrated in literature
reviews of Ahlbom 2000 and Kheifets 2010).
In addition, some epidemiological studies indicate that long term exposure at home or at work to magnetic fields in the range of 1 μT could increase the risk of suffering from Alzheimer disease (Huss et al.
2009, Kheifets et al. 2009). Moreover, there are some studies in which correlations between the use ofelectric devices such as electric blankets, hair dryers and electric razors and the risk of certain tumour
diseases have been observed (Abel et al. 2007, Kleinerman et al. 2005).

The measurement of magnet fields with magnetic field mats
The magnetic fields of three of the magnetic field mats favailable on the Swiss market were measured
by the Zurich University of Applied Sciences on behalf of the FOPH.
The three therapeutic magnetic field mats were surveyed at a distance of 1.5 cm, 10 cm and 30 cm
above the mattress for each of the highest intensity levels. The average magnetic field strength at a
distance of 1.5 cm above the surface was found to be 17 to 94 µT (microtesla) depending on themattress, thereby exceeding the reference level for the general population. The maximum magnetic
field strengths reached between 133 and 461 µT, depending on the mattress, thus exceeding the reference level by 5 to 11 times (Table 2).

Bundesamt für Gesundheit BAG
19 October 2016

Seite 7 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

Table 2: Magnetic fields for three different mats at a distance of 1.5 cm
Average magnetic fieldstrength

Maximum magnetic
field strength

Exceeds the international limit value
by

Mat 1

94 µT

461 µT

11 times

Mat 2

47 µT

170 µT

9 times

Mat 3

17 µT

133 µT

5 timesFigure 2 shows the maximum measured magnetic field as a function of the distance.

Figure 2: Maximum magnetic fields of the three mats as a function of the distance

Figure 3 shows the distribution of the maximum magnetic fields on the three mats. The measurements
show that the exposure increases significantly towards the middle of the mat.

Bundesamt für Gesundheit BAG
19 October 2016

Seite 8 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

Figure 3: Comparison of the maximum magnetic flux density of the three magnetic mattress pads at a distance of 1.5 cm

As the reference level was exceeded by all mats, additional tests were carried out to determine
whether the magnetic fields of the three mats also exceeded the basic restrictions.

Simulation of body currents
Body currents that flow in persons exposed to a magnetic field cannot be measured directly; rather
they have to be calculated with computer simulations in virtual model persons. The research foundation IT’IS in Zurich, on behalf of the FOPH, carried out these simulations for model persons lying in various positions directly on top of a magnetic field mats. The simulations of the body currents also took
into account, besides the exposure to the magnetic field, the gender, age, physical build, anatomy,
tissue properties and posture of the following virtual persons:






Female, 26 years of age, 1.60 m, weight 58 kg
Female, 26 years of age, 1.60 m, in the third, seventh and ninth month of pregnancy
Foetus in the third, seventh and ninth monthBoy, 6 years of age, 1.17 m, weight 20 kg
Male, 34 years of age, 1.74 m, weight 70 kg

The body currents were simulated in both the peripheral nervous system (PNS) and the central nervous system (CNS).
The results of the computer simulation show for a person who is lying on their back in the middle ofthe mat that the basic restrictions for body currents in the peripheral body regions are mostly reachedor exceeded in all model persons and for all three magnetic field mats (Figure 4). For the central nervous system, the limit values were exceeded only for one magnetic mattress pad (Figure 5).
The highest body currents are induced when the model person is not correctly positioned on the magnetic field mat. The highest body currents in the peripheral body region occur in folds of the skin suchas in the armpit or groin. The highest calculated body currents in the central nervous system were in
the brain at the back of the head.
Figure 4 and Figure 5 show the body currents that were induced in the pregnant model person in thesupine position. Figure 6 illustrates the modelled body currents in unborn children for various growthphases during pregnancy. In mat 1 the body currents in the foetus exceed the limit values in the 7th

Bundesamt für Gesundheit BAG
19 October 2016

Seite 9 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

and 9th month. In the 3rd month the calculated body currents are below the limit value. For mats 2 and3 the limit values were not reached in any development stage of the foetus. If the pregnant woman lies
on her side on the mat, the results are very similar. This is mainly due to the fact that the distance separating the foetus from the mat is similar in the supine and lateral positions.

Figure 4: Calculated values expressed as a % limit value for body currents in the whole body (peripheral nervous system PNS)
of model persons, who are lying in the middle of the mattress and in the supine position on the magnetic mattress pad. 100%
corresponds to the ICNIRP limit value for the general population.

Bundesamt für Gesundheit BAG
19 October 2016

Seite 10 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

Figure 5: Calculated values expressed as a % limit value for body currents in the central nervous system (CNS; brain and spinalcord) of model persons, who are lying in the middle of the mattress and in the supine position on the magnetic mattress pad.
100% corresponds to the ICNIRP limit value for the general population.

Figure 6: For body currents in the foetus in the whole body (peripheral nervous system, PNS) and in the central nervous system(CNS; brain and spinal cord) when the mother is lying in the middle of the mattress and in the supine position on the magnetic
mattress pad. 100% corresponds to the limit value for the general population.

Bundesamt für Gesundheit BAG
19 October 2016

Seite 11 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

Effect of magnetic field mats on pacemakers:
Caution should be exercised with magnetic field mats that are used at maximum power. Unipolar
pacemakers and bipolar pacemakers in unipolar mode are particularly susceptible to interference frommagnetic fields

Side effects when using therapeutic magnetic field mats
In the twelve studies evaluated by the Swiss Tropical and Public Health Institute, no acute side effects
were reported for the use of magnetic field mats. However, there were no studies that specifically dealt
with investigations of side effects. Undesirable long-term effects were not investigated in any study,
either.

3 Assessment of the use of therapeutic magnetic
field mats
In the case where magnetic field mats are declared as medical devices, they do not have to comply
with limit values. However, the manufacturers have to prove that the benefits of their products are greater than the risk accompanying the treatment. According to the systematic literature review mandated
by the FOPH, at present there are only 12 scientifically published randomised double blind studies on
the therapeutic use of magnetic mattress pads (Hug und Röösli 2011). These studies do not provide
any overwhelming proof of the benefits and the efficacy of magnetic mattress pads. Moreover, thefields generated by these mattresses are comparatively high and possible health risks from long-term
use cannot be assessed. Consequently, the use of magnetic mattress pads cannot be recommended
at the present time. In accordance with the precautionary principle, children and pregnant womenshould avoid using such mattresses.

4 Technical data of Magnetic field matsFrequency
Low frequency: 50 Hertz (Hz) when the magnetic field mat is switched on
Medium frequency: 0.01 Hz to 20 kHz Kilohertz (kHz) (source: distributor/manufacturer)
Measured: 30 to 250 Hz (source: ZHAW)
Signal forms
The three measured magnetic field mats generate three different signal forms. The duration of the individual signals, the form of the signals and the number of impulses per signal are different. The signals of all the surveyed magnetic field mats are triangular.
The various programmes of each mat differ in the temporal sequence of the individual signals, in theamplitude, in the number of signal peaks or in the repeat frequency of the individual signal packets.

Bundesamt für Gesundheit BAG
19 October 2016

Seite 12 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

Frequency spectra
The measured magnetic field mats operate principally with very low frequency fields. However, theband width is extended by the triangular signal and the frequency spectrum is broadened by up to2000 Hertz. In Table 3 are presented the three main frequencies (i=1; i=2; i=3) of a signal packet.
Table 3: An overview of the three main frequencies (i=1; i=2; i=3) of the three magnetic mattress pads

Mat 1
Mat 2
Mat 3
Frequency Frequency Frequency
[Hz]
[Hz]
[Hz]

Bundesamt für Gesundheit BAG
19 October 2016

i=1

3.8

32

3

i=2

15

210

24

i=3

210

1667

238

Seite 13 von 13

Eidgenössisches Departement des Innern EDI
Bundesamt für Gesundheit BAG

5. Literature
1. Abel, E. L.; Hendrix, S. L.; McNeeley, G. S.; O'Leary, E. S.; Mossavar-Rahmani, Y.; Johnson, S.
R.; Kruger, M. (2007): Use of electric blankets and association with prevalence of endometrial
cancer 1. In: Eur.J Cancer Prev. 16 (3), S. 243–250.
2. Ahlbom, A.; Day, N.; Feychting, M.; Roman, E.; Skinner, J.; Dockerty, J. D. et al. (2000): A pooled
analysis of magnetic fields and childhood leukaemia 2. In: Br.J.Cancer 83 (5), S. 692–698.
3. de Santis, V.; Douglas, M.; Nadakuduti, J.; Benkler, S.; Chen, X.L.; Kuster, N. (2015): Human exposure from pulsed magnetic field therapy mats: a numerical case study with three commercial
products. In: Bioelectromagnetics 36 (2), S. 149–161.
4. Hug, K.; Röösli, M. (2012): Therapeutic effects of whole-body devices applying pulsed electromagnetic fields (PEMF): a systematic literature review. In: Bioelectromagnetics 33 (2), S. 95–105.
5. Huss, A.; Spoerri, A.; Egger, M. Röösli, M. (2009): Residence near power lines and mortality fromneurodegenerative diseases: longitudinal study of the Swiss population. In: American journal of
epidemiology 169 (2), S. 167–175.
6. Jaermann, T.; Suter, F.; Osterwalder, D.; Luechinger, R. (2011): Measurement and analysis ofelectromagnetic fields of pulsed magnetic field therapy systems for private use. In: J Radiol.Prot.
31 (1), S. 107–116.
7. Kheifets, L.; Bowman, J. D.; Checkoway, H.; Feychting, M.; Harrington, J. M.; Kavet, R. et al.
(2009): Future needs of occupational epidemiology of extremely low frequency electric and magnetic fields: review and recommendations. In: Occupational and Environmental Medicine 66 (2), S.
72–80.
8. Kheifets, L.; Renew, D.; Sias, G.; Swanson, J. (2010): Extremely low frequency electric fields andcancer: assessing the evidence. In: Bioelectromagnetics 31 (2), S. 89–101.
9. Kleinerman, R. A.; Linet, M. S.; Hatch, E. E.; Tarone, R. E.; Black, P. M.; Selker, R. G. et al.
(2005): Self-reported Electrical Appliance Use and Risk of Adult Brain Tumors. In: Am.J Epidemiol. 161 (2), S. 136–146.
Specialist staff
Federal Office of Public Health FOPH
emf@bag.admin.ch

Bundesamt für Gesundheit BAG
19. Oktober 2016

Seite 14 von 14