Induction Cooking and Implanted Medical Devices

Why this matters

Induction is the cooktop most conversions end up recommending: fast, efficient, no combustion in the kitchen. It works by putting a strong alternating magnetic field into the pan, and that field is the reason the cooktop's own manual carries a warning about pacemakers. Manufacturers of both induction cooktops and of cardiac implants advise people with those implants to keep a distance from an operating cooking zone. A shop that sells induction to every customer without knowing this can end up having recommended it to a household where the cook has a defibrillator under the left collarbone, and nobody mentioned it because nobody asked.

You cannot answer the medical question and should not try. What you can do is make sure the customer knows the question exists, send them to the people who can answer it, and give them a kitchen plan that works either way. This is not medical advice; the device maker and the patient's physician are the authority. The cooktop itself, its circuit and cookware, are owned by Induction Cooking Conversion Reference.

What the cooktop actually emits

An induction zone is a flat coil under the glass driven with alternating current, typically in the range of roughly 20 to 100 kHz. The coil's magnetic field passes through the glass into a ferromagnetic pan and induces currents in the pan's base, which heat it. The glass itself only gets hot from the pan.

Three properties of that field are worth understanding, because they explain the advice:

• It falls off steeply with distance. The field is concentrated at the coil and drops quickly as you move away from it, faster than in proportion to distance. A few extra inches matter a lot.
• The pan shapes it. A pan that covers the zone fully and sits centered captures most of the field. A pan smaller than the zone, pushed off center, warped so it rocks, or made of a material only partly magnetic, lets more of it leak out around the edges. So does running a zone at high power or on a boost setting.
• It is strongest at the front edge of the cook. A person standing at the cooktop puts their torso a short distance from the front zones and further from the rear ones. Leaning over a pot closes that gap.

None of this means induction is unsafe for most people. It means the field is real, local, and larger in some conditions than others, which is exactly the kind of exposure implant makers write guidance about.

What the device makers say, in general terms

Cardiac implants. Pacemakers and implantable cardioverter-defibrillators (ICDs) sense the heart's electrical signals through leads and respond to them. A strong enough external field can, in principle, be sensed as a signal: a pacemaker might withhold or alter pacing, and an ICD might withhold therapy or, in a worst case, deliver one it should not. Manufacturers' patient materials list induction cooktops among household sources of electromagnetic interference and advise keeping the implant some distance from an operating cooking zone. The recommended distance differs between makers and device families, and some of the guidance depends on how the device's leads are configured, which only the patient's device record answers. Published laboratory studies found interference possible mainly under unfavorable conditions (certain lead configurations, standing very close, an ill-fitting pan), which is consistent with the field behavior above and is not a reason to dismiss the guidance.

Other implants. Neurostimulators, implanted drug pumps, cochlear implants and some insulin pumps also carry interference guidance from their own makers, and it is not the same guidance as a pacemaker's. Do not generalize from one device to another.

What a cooktop's compliance means and does not. Induction cooktops sold in the US are regulated as consumer industrial, scientific and medical equipment under 47 CFR Part 18, which limits radio interference, and they carry a safety listing to the applicable UL standard for household cooking appliances. Neither is a statement that the cooktop is compatible with a given implant. A listed, compliant cooktop still carries the pacemaker warning in its manual.

Your role, and where it ends

Offer the information to everyone. Put one plain line on every induction proposal and say it out loud at the kitchen walk-through: people with a pacemaker, defibrillator or other implanted device should check with their device maker and physician before choosing induction. This is not a screening question and it is not yours to ask about anyone's health. Offering it to everyone is what avoids singling anyone out.

If the customer tells you someone has a device, stop recommending and start supplying. Supply three things the customer can take to the physician and the device clinic: the cooktop's installation and use manual (the warning section and any stated frequency or power data), the kitchen layout with measured distances from where the cook stands to each zone, and the alternative you would install instead.

Where you stop. The decision about whether induction is acceptable for that person, at what distance, and under what habits belongs to their physician and device maker. Do not tell the customer it is fine, and do not tell them it is dangerous. "The manufacturers say to check, and here is what your doctor will want to see" is the whole of your medical content.

Record it with care. Job notes are read by many people. Record what the customer chose and that it was their choice ("customer selected radiant cooktop; induction declined at customer request"), not the medical detail behind it, unless the customer asks you to note it.

Do not demonstrate an operating induction zone with the customer who has the device leaning over it during a showroom or in-home demonstration.

Worked example: the measured kitchen

A couple converting off gas chooses an induction range for a wall-side range location. During the kitchen walk-through, after the tech reads the standard line, one of them says they have an ICD and do most of the cooking.

The tech measures the existing layout with a tape, standing at the counter in the cook's usual position. Distances are from the front edge of the counter to each zone's center, and the numbers below are this kitchen's, not general figures.

• Front zones: center about 7 inches from the counter edge. A person standing at the edge with their chest a few inches back from it puts the device on the order of 10 to 12 inches from a front zone's center, closer when leaning over a pot.
• Rear zones: center about 17 inches from the counter edge, so on the order of 20 to 22 inches standing upright.

The tech does not compare those to any distance. The tech writes them on the layout sheet, attaches the range's manual pages with the warning, and names two alternatives: a radiant electric smoothtop range of similar rating, which heats with resistance elements and produces no induction field, and keeping the gas range, which keeps a gas account for one appliance (see related: Keeping Gas for One Appliance, for what that costs).

The customer takes the sheet to their device clinic. Two weeks later they choose the radiant range. The new 240 V circuit planned for the induction range serves it, because its instructions call for the same circuit rating; the tech checks that before ordering rather than assuming it.

What would have changed it. If the device maker's guidance, as the clinic applied it, had been satisfied at the rear-zone distance but not the front, the couple could have chosen induction and committed to cooking on the rear zones, or a cooktop installed in a deeper counter or an island where the stance sits further back. That is a habit decision for them, not a layout trick for you to sell; a rule that depends on always remembering to use the back burners is weaker than one that does not. If the household's cook had been the other person, the question might not have arisen for the kitchen at all, though anyone with a device standing beside the cook is still in the same field.

What the failure looks like. The version of this job that goes wrong is ordinary: the tech never says the line, the customer does not think to mention the device, the range goes in, and months later the cardiologist asks about kitchen appliances. Now the household has a new range they may want to replace, and a shop that sold it without mentioning a warning printed in the manual it installed.

The alternatives, compared honestly

A radiant or coil electric range still completes the electrification and usually needs the same circuit as induction of similar rating. Gas keeps combustion in the kitchen, which matters for a household that converted partly for indoor air.

How to verify you handled it well

Every induction proposal your shop sends carries the device line, and the person doing the walk-through says it. When a customer discloses a device, the file shows that the manual pages, measured layout and alternatives were handed over, that the customer made the choice after consulting their own physician or device maker, and that the job notes record the choice without medical detail. Nobody at your shop has told a customer whether induction is safe for their device.

References

• Implant manufacturers' patient guidance on electromagnetic interference from household appliances, and the cooktop manufacturer's use and care manual
• 47 CFR Part 18, Industrial, Scientific, and Medical Equipment (FCC)
• US FDA information for patients on implanted cardiac devices and electromagnetic interference
• See related: Induction Cooking Conversion Reference; Keeping Gas for One Appliance; How to Walk a Customer Through an Electrification Plan