Building Biology and EMF Glossary

You are reading an assessment report, or halfway through one of the guides on this site, and a term stops you cold. Building biology draws from electrical engineering, indoor air science, mycology, and environmental health, the vocabulary piles up fast. This glossary covers the terms that come up most often, with links to the relevant guides.

A

AC Electric Field

An electric field produced by voltage in household wiring, cables, and plugged-in devices, even when nothing is turned on. These fields couple directly to your body and are often quantified as body voltage measured while lying in bed. The SBM-2008 flags field strengths above 1 V/m as a slight concern for sleeping areas. More in the electric field guide.

AC Magnetic Field

A magnetic field produced by current flowing through wires and appliances. Magnetic fields pass through walls and most building materials and cannot be conventionally shielded, the only practical fixes are distance or eliminating the source. The SBM-2008 "No Concern" threshold for sleeping areas is below 0.2 mG (20 nT). See the magnetic field guide.

Alpha Track Detector

A passive device used for long-term radon measurement, typically deployed for 90 days to one year. A plastic film inside records alpha particle tracks from radon decay, then gets sent to a lab for counting. Because alpha track detectors smooth out daily and seasonal swings, they give a more reliable average than short-term charcoal tests. See the radon testing guide.

B

Bau-Biologie

The German term for building biology, literally "building life-science." The discipline originated in Germany in the 1960s and 1970s, formalized by Prof. Dr. Anton Schneider through the IBN in Rosenheim. English-speaking practitioners still use the German name to reference its origins. See What Is Building Biology?

BBEC (Building Biology Environmental Consultant)

A professional certification issued by the Building Biology Institute. A BBEC has completed the full training curriculum covering EMF, indoor air quality, mold, and building materials, and has passed the certification exam. The related credential EMRS focuses specifically on electromagnetic radiation. See Find a Building Biologist or the certifications guide.

BBI (Building Biology Institute)

The North American organization that maintains building biology training and certification programs. Founded by Helmut Ziehe in 1987 as the Institute for Bau-Biologie & Ecology (IBE) and since rebranded. BBI offers the BBEC and EMRS certifications and maintains the English-language SBM standards.

Bioinitiative Report

A research compilation on the biological effects of electromagnetic fields, first published in 2007 and updated in 2012. It reviews thousands of peer-reviewed studies and argues that government exposure limits (based on thermal effects) are inadequate to protect against non-thermal biological effects. Frequently cited as scientific support for precautionary limits like those in the SBM-2008.

Body Voltage

A way of measuring your actual exposure to AC electric fields while lying in bed. A multimeter reads the voltage (in millivolts) that surrounding wiring has induced on your body via a handheld probe. The SBM-2008 considers body voltage below 10 mV no concern; most modern bedrooms measure 200–2,000 mV. The EMF assessment guide covers the method in detail.

Building Biology

The study of how the indoor environment affects human health. It evaluates homes across multiple categories. EMF, indoor air quality, mold, building materials, ventilation, and moisture, and compares conditions to precautionary thresholds. The discipline originated in Germany as Bau-Biologie; its central idea is the "third skin" concept: your home should support your health the way your own skin does. See What Is Building Biology?

C

CO2 (Carbon Dioxide)

A colorless, odorless gas that accumulates in occupied indoor spaces. CO2 is measured as a proxy for ventilation, outdoor air sits around 420 ppm, and the SBM-2008 flags indoor levels above 600 ppm as a slight concern. When CO2 is high, other contaminants (VOCs, formaldehyde, moisture) are accumulating too. See the indoor air quality testing guide.

D

DECT (Digital Enhanced Cordless Telecommunications)

A wireless protocol used by most cordless phones. DECT base stations transmit pulsed RF radiation continuously, 24 hours a day, whether or not a call is in progress. A DECT base near a bedroom is one of the most common sources of elevated RF found during assessments. Building biologists usually recommend replacing them with corded phones in sleeping areas.

Demand Switch

An electrical device (also called a circuit cut-off switch or Netzfreischalter) that automatically disconnects voltage from a circuit when no current is being drawn, eliminating the AC electric field from the wiring. When you flip a switch, it senses the load and restores power instantly. Installing one on the bedroom circuit is one of the most effective single steps for reducing nighttime electric field exposure. See the electric field guide.

Dirty Electricity

High-frequency voltage transients (roughly 2 kHz to 10 MHz) that ride on a home's standard 50/60 Hz wiring, created when devices chop or convert AC power. LED/CFL bulbs, dimmer switches, solar inverters, and switching power supplies are common sources. Measured in GS units using a Stetzerizer or Greenwave meter. See the dirty electricity guide.

E

EHS (Electromagnetic Hypersensitivity)

A condition where people report symptoms, headaches, sleep disturbance, fatigue, difficulty concentrating, that they attribute to EMF exposure. The WHO recognizes EHS as real and sometimes disabling, though not as a formal medical diagnosis. Building biology takes a practical view: reduce EMF in sleeping areas and see if symptoms improve.

ELF (Extremely Low Frequency)

The portion of the electromagnetic spectrum from 3 Hz to 300 Hz. Household electricity (50/60 Hz) falls within the ELF range, so AC magnetic fields and AC electric fields from wiring are ELF fields. IARC classifies ELF magnetic fields as Group 2B, possibly carcinogenic, based on epidemiological associations with childhood leukemia.

EMF (Electromagnetic Field)

In building biology, EMF covers four categories measured during a home assessment: AC electric fields, AC magnetic fields, RF radiation, and dirty electricity. Each behaves differently, comes from different sources, and needs different instruments. See the EMF assessment guide.

EMRS (Electromagnetic Radiation Specialist)

A professional certification from the Building Biology Institute focused on measuring and mitigating electromagnetic fields. The EMRS credential covers all four EMF types, while the BBEC covers the broader scope of building biology. See Find a Building Biologist.

EPA (Environmental Protection Agency)

The U.S. federal agency responsible for protecting human health and the environment. Most relevant here for its guidance on radon (recommending mitigation above 4 pCi/L), indoor air quality, and mold. The EPA does not regulate EMF exposure.

ERMI (Environmental Relative Moldiness Index)

A DNA-based mold testing method developed by the EPA. ERMI uses qPCR analysis of settled dust to identify and quantify 36 mold species, producing a single index number compared to a national reference database. It catches species that spore traps miss, including mold present in dust but not actively sporulating. See the mold testing guide.

F

Formaldehyde

A volatile organic compound that off-gasses from engineered wood products (plywood, particleboard, MDF), insulation, textiles, and adhesives. IARC classifies formaldehyde as a Group 1 carcinogen, confirmed carcinogenic to humans. The SBM-2008 flags indoor concentrations above 20 µg/m³ as a slight concern. See the VOC and formaldehyde testing guide.

G

Gaussmeter

An instrument that measures AC magnetic field strength in milligauss (mG) or nanotesla (nT). Three-axis models measure all three planes at once; single-axis models must be rotated to find the peak. See the EMF meters buying guide.

GS Units (Graham-Stetzer Units)

A proprietary unit for measuring dirty electricity, read by the Stetzerizer Microsurge Meter. GS units quantify the rate of change of high-frequency voltage on household wiring. Below 50 GS units is no concern; many homes read 200–1,000+ before remediation. See the dirty electricity guide.

H

HEPA (High-Efficiency Particulate Air)

A filter standard requiring capture of at least 99.97% of particles 0.3 microns in diameter. HEPA filtration matters during mold remediation and for reducing fine particulate matter indoors. True HEPA is a defined standard, marketing terms like "HEPA-type" or "HEPA-like" do not meet it.

HERTSMI-2 (Health Effects Roster of Type-Specific Formers of Mycotoxins and Inflammagens, 2nd Version)

A simplified mold scoring system derived from ERMI data, focusing on five mold species known to produce mycotoxins: Aspergillus penicillioides, Aspergillus versicolor, Chaetomium globosum, Stachybotrys chartarum, and Wallemia sebi. A score below 11 is generally considered safe. Uses the same qPCR dust sample as ERMI. See the mold testing guide.

HRV/ERV (Heat Recovery Ventilator / Energy Recovery Ventilator)

Mechanical ventilation systems that bring fresh outdoor air into a building while recovering heat (HRV) or both heat and moisture (ERV) from the outgoing air. They address a real trade-off in tight, energy-efficient buildings: you need ventilation to prevent CO2, VOC, and moisture buildup, but you don't want to dump conditioned air outside. See the indoor air quality testing guide.

HVAC (Heating, Ventilation, and Air Conditioning)

The mechanical systems controlling temperature, humidity, and air circulation in a building. Building biologists evaluate HVAC for duct cleanliness, filter quality, moisture control, and fresh air exchange. Poorly maintained systems can spread mold spores and chemical contaminants through the whole house.

I

IARC (International Agency for Research on Cancer)

A WHO agency that evaluates carcinogenic potential of substances and exposures. Classifications that come up in building biology: ELF magnetic fields (Group 2B, possibly carcinogenic), RF radiation (Group 2B), formaldehyde (Group 1, confirmed carcinogenic), and radon (Group 1).

IBN (Institut für Baubiologie + Nachhaltigkeit)

The Institute for Building Biology + Sustainability, founded by Prof. Dr. Anton Schneider in Rosenheim, Germany. The IBN developed the original Bau-Biologie training curriculum and, with Wolfgang Maes, created the SBM standard used by building biologists worldwide. See What Is Building Biology?

ICNIRP (International Commission on Non-Ionizing Radiation Protection)

An independent organization that publishes guidelines for limiting exposure to non-ionizing radiation. Most countries base their national limits on ICNIRP. Building biology considers these limits inadequate, they protect against acute thermal effects but not chronic low-level exposures. The SBM-2008 thresholds are orders of magnitude lower.

Ionizing Radiation

Radiation with enough energy to remove electrons from atoms, damaging DNA directly. X-rays, gamma rays, and the alpha particles emitted by radon decay are ionizing. Building biology deals with ionizing radiation primarily through radon testing and mitigation, separate from the non-ionizing radiation produced by household wiring and wireless devices.

M

mG (Milligauss)

The unit most commonly used in North America for AC magnetic field strength. One milligauss equals 100 nanotesla (nT). The SBM-2008 puts the no-concern threshold at 0.2 mG for sleeping areas; above 5 mG is extreme concern.

Microinverter

A small power inverter installed on each individual solar panel, converting DC to AC at the panel rather than at a central string inverter. Microinverters can be a significant source of dirty electricity because each one injects high-frequency switching noise onto household wiring. See the dirty electricity guide.

Mu-Metal

A nickel-iron alloy with high magnetic permeability, used to shield areas from AC magnetic fields that pass through ordinary materials. Mu-metal absorbs and redirects magnetic flux lines. Expensive, and typically a last resort when the source cannot be eliminated or distance is not an option. See the EMF shielding guide.

N

nT (Nanotesla)

The SI unit for AC magnetic field strength, used more commonly in Europe and in the SBM-2008 standard alongside milligauss. One nanotesla equals 0.01 mG. The SBM-2008 "No Concern" threshold for sleeping areas is below 20 nT (0.2 mG).

Non-Ionizing Radiation

Radiation that lacks the energy to remove electrons from atoms, including ELF fields from wiring, RF radiation from wireless devices, visible light, and infrared. Whether chronic low-level exposure causes biological effects through non-thermal pathways is the question at the heart of EMF health research.

NTP Study

A large-scale toxicology study by the U.S. National Toxicology Program (2018) in which rats were exposed to RF radiation at cell phone frequencies for two years. The study found "clear evidence" of heart schwannomas and "some evidence" of brain gliomas in male rats, frequently cited as grounds for upgrading IARC's Group 2B classification for RF.

O

Off-Gassing

The release of volatile organic compounds from solid materials into indoor air at room temperature. New furniture, flooring, paint, adhesives, and engineered wood products are common sources. Rates are highest when materials are new, but products containing formaldehyde resins can keep off-gassing for years. See the VOC and formaldehyde testing guide.

P

PID Meter (Photoionization Detector)

A handheld instrument that measures total volatile organic compound concentrations in real time by ionizing gas molecules with an ultraviolet lamp. PID meters give immediate readings, walk through a building and watch the numbers change near potential sources. They measure TVOC but do not identify individual compounds. See the indoor air quality testing guide.

Power Density

The amount of RF radiation energy passing through a given area, expressed in microwatts per square meter (µW/m²) in building biology. Power density is the standard unit for RF measurements and the one used in the SBM-2008 RF threshold tables.

Precautionary Principle

The idea that when reasonable evidence of potential harm exists, protective action should be taken without waiting for full scientific proof. Building biology applies this throughout: the SBM-2008 sets thresholds far below government limits, treats nature as the reference standard, and favours less exposure over more. See the SBM-2008 guide.

Q

qPCR (Quantitative Polymerase Chain Reaction)

A laboratory technique that identifies and quantifies specific mold species by amplifying their DNA. qPCR is the method behind ERMI and HERTSMI-2 testing, and it can detect species present in dust but not actively sporulating, an advantage over spore traps. See the mold testing guide.

R

Radon

A naturally occurring radioactive gas produced by uranium decay in soil and rock, seeping into buildings through foundation cracks, slab joints, and sump pits. Colorless and odorless, radon is the second leading cause of lung cancer in the United States after smoking. The EPA recommends mitigation above 4 pCi/L; the SBM-2008 flags slight concern at 30 Bq/m³ (roughly 0.8 pCi/L). See the radon testing guide.

RF (Radiofrequency) Radiation

Electromagnetic radiation in the frequency range of roughly 100 kHz to 300 GHz. WiFi routers, cell towers, DECT cordless phones, smart meters, Bluetooth devices, baby monitors. RF is measured as power density in µW/m². The SBM-2008 flags levels above 0.1 µW/m² as a slight concern for sleeping areas, orders of magnitude below ICNIRP limits. See the RF radiation guide.

S

SBM-2008 (Standard der Baubiologischen Messtechnik)

The Standard of Building Biology Testing Methods, the reference framework building biologists worldwide use to evaluate sleeping-area conditions. Created by Wolfgang Maes and the IBN, first published in 1992. The SBM grades every measurement into four levels (No Concern, Slight Concern, Severe Concern, Extreme Concern) across EMF, indoor air quality, radioactivity, fungi, and other categories. See the complete SBM-2008 reference.

Shielded Cable

Electrical wiring with a grounded conductive layer that contains the AC electric field within the cable rather than letting it radiate into the room. Standard Romex/NM-B cable is unshielded; alternatives like MC cable or European BIO cable can cut electric field levels by 90% or more. Most practical for new construction or renovation. See the electric field guide.

Spore Trap

An air sampling method for mold testing: a pump draws air across a sticky cassette that is then examined under a microscope. Spore traps capture what is airborne at the moment of collection, useful for comparing indoor versus outdoor counts, but they miss mold not actively sporulating. See the mold testing guide.

Stachybotrys

Stachybotrys chartarum, commonly called "black mold," is a toxigenic species that grows on water-damaged cellulose materials (drywall paper, ceiling tiles, wood) and produces satratoxin mycotoxins. It is one of the five species tracked by the HERTSMI-2 scoring system, and its presence points to sustained water intrusion.

Sub-Slab Depressurization

The most common method for reducing radon levels. A pipe inserted through the foundation slab connects to a fan that draws radon-laden air from beneath the building and vents it above the roofline. Done properly, a sub-slab system cuts indoor radon by 80–99%. See the radon testing guide.

T

TVOC (Total Volatile Organic Compounds)

The combined concentration of all volatile organic compounds in an air sample, expressed in µg/m³ or ppb. TVOC is a screening number, useful as an air quality indicator but no substitute for identifying individual compounds. The SBM-2008 puts no concern below 200 µg/m³. See the indoor air quality testing guide.

V

V/m (Volts per Meter)

The standard unit for AC electric field strength. The SBM-2008 threshold for "slight concern" is 1 V/m; ICNIRP sets its general public limit at 5,000 V/m. In practice, building biologists often prefer body voltage (in millivolts) because it captures actual coupled exposure.

VOC (Volatile Organic Compound)

A broad category of carbon-based chemicals that evaporate at room temperature, releasing gases into indoor air from paints, adhesives, flooring, furniture, and building materials. Some (like formaldehyde and benzene) are known carcinogens; others cause respiratory irritation or headaches at typical indoor concentrations. Testing can measure TVOC as a screening tool or identify individual compounds via lab analysis. See the VOC and formaldehyde testing guide.

µ

µW/m² (Microwatts per Square Meter)

The unit of power density used in building biology for RF radiation levels. The SBM-2008 puts no concern below 0.1 µW/m² for sleeping areas; above 1,000 µW/m² is extreme concern. Government limits in most countries sit between 2,000,000 and 10,000,000 µW/m², four to five orders of magnitude higher.

Looking Something Up?

For the full testing protocol, see the EMF assessment guide and the indoor air quality testing guide. For threshold values, see the SBM-2008 reference. For the philosophy behind it all, start with What Is Building Biology? Or, to have a professional handle the testing, see Find a Building Biologist.

The field has its own vocabulary. Once you know what the terms mean, the measurements make sense, and so do the next steps.