Mold Remediation Glossary (S520 & AMRT Exam Terms)

150 terms from the ANSI/IICRC S520 world, written the way a technician would explain them on a job site. Search, filter by topic, or jump to a letter — every entry links to the page that goes deeper.

By the AMRTTraining.com team

Studying these? Drill them with the AMRT flashcards.

150 terms

A

Abrasive method

Methods

Sanding, wire brushing or blasting to remove growth that has penetrated a semi-porous surface such as framing. It generates heavy airborne debris, so it belongs inside full containment with HEPA filtration running.

See also: Attic mold remediation

ACACAmerican Council for Accredited Certification

Certification & licensing

An independent certification body offering credentials for indoor environmental consultants and mold professionals, including assessment-side roles the IICRC does not cover. Requirements come from ACAC directly.

ACHAir changes per hour

Engineering controls

How many times the air inside a containment is replaced in an hour. It is calculated from machine airflow and containment volume, and it is the number used to size equipment for a work area.

AFDAir filtration device

Engineering controls

A HEPA-filtered blower used to filter air inside a work area or to create negative pressure when exhausted outside it. The same machine can serve either role depending on how it is configured.

Air sampling

Verification & documentation

Drawing a measured volume of air through a collection device to estimate airborne spore levels. Indoor results are only meaningful when compared with an outdoor or unaffected-area reference taken the same day.

See also: PRV and clearance

Air scrubber

Engineering controls

A HEPA-filtered unit recirculating air inside containment to pull particles out of the work-area air. Scrubbing reduces airborne load during and after the dirty work; it does not by itself create negative pressure.

Airlock

Engineering controls

A two-flap or two-stage entry that keeps air from rushing straight into containment when someone passes through. It preserves negative pressure and keeps dust from puffing into clean space.

See also: Containment types explained

Allergen

Microbiology

A substance that triggers an immune response in sensitized people. Fungal spores, fragments and proteins act as allergens, which is why occupant sensitivity can drive containment decisions on an otherwise small job.

Amplification

Microbiology

Growth of a fungal population indoors beyond normal background levels. Amplification is what turns ordinary settled spores into a contamination problem, and it always traces back to a moisture source.

AMRTApplied Microbial Remediation Technician

Certification & licensing

The IICRC certification for technicians performing mold and microbial remediation, covering the topics in the ANSI/IICRC S520 standard. It is earned by completing an approved course and passing the AMRT exam.

Antimicrobial

Methods

The general term for products marketed to kill or inhibit microorganisms. In mold work they are optional supporting tools whose use, product and label directions all belong in the documentation.

APFAssigned protection factor

PPE

The level of protection a respirator class is expected to provide when used correctly within a full program. APF is how respirator options are compared when the exposure calls for a step up.

See also: PPE by Condition

ASDApplied Structural Drying

Certification & licensing

The IICRC certification focused on drying water-damaged structures — psychrometry, equipment placement and difficult drying situations. It builds on WRT and complements AMRT rather than replacing it.

Aspergillus

Microbiology

A very common indoor mold genus found in dust and on damp materials. Aspergillus and Penicillium are frequently reported together on lab results because their spores look alike under a spore-trap analysis.

See also: Mold biology basics

B

Bacteria

Microbiology

Single-celled organisms that become a primary concern in grossly contaminated water losses. Sewage work is treated as a bacterial and pathogen problem first, with fungal growth as the follow-on risk if drying is slow.

See also: Category 3 sewage remediation

Baseline sampleOutdoor control sample

Verification & documentation

The outdoor or unaffected indoor sample used as the reference for interpreting indoor results. Without a baseline taken the same day, an indoor spore count says very little on its own.

See also: PRV and clearance

Biocide

Methods

A product intended to kill microorganisms, used only in a supporting role and strictly according to its label. Killing growth does not remove the material, the fragments or the allergens.

Bulk sample

Verification & documentation

A piece of the actual material sent to the laboratory for analysis. It is used when identification matters more than a surface snapshot, such as confirming growth inside an assembly.

See also: PRV and clearance

C

Capillary action

Moisture

The way liquid water travels through the pores of a material, including upward against gravity. It explains why a slab leak shows up as damp drywall well above the floor line.

See also: Mold behind drywall

Category 1 water

Moisture

Water from a clean source with no significant contaminants, such as a supply line break. Category 1 can deteriorate over time as it contacts building materials and soils, so timing matters as much as origin.

Category 2 water

Moisture

Water carrying significant contamination that can cause illness on contact — appliance discharge and similar sources. Handling is stricter than Category 1, and delays push a Category 2 loss toward Category 3.

Category 3 water

Moisture

Grossly contaminated water that may contain pathogens and other harmful agents. It drives the strictest PPE, containment and disposal decisions, and porous materials in contact with it are generally removed.

See also: Category 3 sewage remediation

CECContinuing education credit

Certification & licensing

Credit earned from approved training that keeps a certification current. IICRC certifications are maintained with continuing education and the applicable renewal fees; confirm current requirements with the IICRC.

Certificate of Mold Damage Remediation

Verification & documentation

A closing document some states require the remediator to provide to the property owner after a mold job. Requirements and forms differ by state, so confirm the current version with the state agency.

Certified FirmIICRC Certified Firm

Certification & licensing

A company registration with the IICRC, distinct from an individual technician certification. Firms agree to the IICRC's requirements for certified companies; individuals still hold their own credentials.

CFMCubic feet per minute

Engineering controls

The volume of air a machine moves each minute. Rated CFM is measured under ideal conditions, so real airflow drops as filters load and ducting is added.

Chaetomium

Microbiology

A mold associated with wet cellulose materials such as saturated drywall and water-damaged wood. Like Stachybotrys, finding it generally indicates sustained wetting rather than brief elevated humidity.

See also: Mold behind drywall

Chain of custody

Verification & documentation

The signed record tracking every sample from collection to the laboratory. A broken chain of custody makes the result easy to challenge, which matters most on the jobs that end up in dispute.

See also: Documentation on a mold job

Cladosporium

Microbiology

One of the most common molds in outdoor air and a frequent indoor finding on damp surfaces. Because outdoor levels are usually high, indoor results are interpreted against an outdoor reference sample.

See also: PRV and clearance

Clearance

Verification & documentation

The determination that a work area meets the criteria set in the protocol and can be released. Clearance is best decided by someone independent of the contractor who performed the remediation.

See also: PRV and clearance

CMRCouncil-certified Microbial Remediator

Certification & licensing

An ACAC credential for professionals performing microbial remediation. It is a separate track from the IICRC's technician certifications, with its own eligibility and renewal rules.

CMRSCouncil-certified Microbial Remediation Supervisor

Certification & licensing

An ACAC credential for those supervising microbial remediation projects. Some state licensing programs recognize third-party credentials like this, so check the state agency before assuming it counts.

See also: Mold licensing by state

Colony forming unitCFU

Microbiology

The unit a laboratory reports when it grows a sample on culture media. A CFU count reflects organisms that survived and grew, so it describes viable contamination rather than everything present in the sample.

See also: PRV and clearance

Condensation

Moisture

Water forming on a surface that is colder than the dew point of the surrounding air. Chronic condensation on windows, ducts or rim joists is a moisture source that must be corrected, not just cleaned.

See also: Moisture control

Condition 1Normal fungal ecology

S520 & standards

An indoor area with fungal levels and species comparable to a clean, similar indoor space. Condition 1 is the goal of every remediation project — you are returning the building to normal, not sterilizing it.

Condition 2

S520 & standards

An area contaminated with settled spores and fungal fragments that migrated from a growth area, without active growth of its own. Condition 2 areas are cleaned rather than demolished, but they still belong inside the scope.

Condition 3

S520 & standards

An area with actual, active mold growth plus the spores and fragments that come with it. Condition 3 drives the heaviest engineering controls, the removal of affected porous materials and the strictest PPE on the job.

Conflict of interest

Verification & documentation

The problem created when the company doing the remediation also declares its own work clean. Independent verification is the standard answer, and some states address it in their licensing rules.

See also: Mold licensing by state

Containment

Engineering controls

The physical isolation of a work area using sheeting, sealed openings and controlled air pressure so spores and dust do not migrate into clean space. The level of containment scales with the contamination and the occupants.

See also: Containment types explained

Containment volume

Engineering controls

Length times width times height of the sealed work area, in cubic feet. Every airflow and equipment decision starts here, which is why it is the first field on any sizing calculator.

Contents remediation

Methods

Deciding item by item whether personal property can be cleaned reliably, needs specialty treatment, or has to be discarded. Porous, heavily contaminated and low-value items are the usual write-offs.

Controlled demolition

Methods

Removing contaminated porous materials deliberately and with minimal disturbance, inside containment with filtration running. It is the opposite of dry, uncontained tear-out that spreads spores everywhere.

See also: Mold behind drywall

Coveralls

PPE

Disposable full-body suits that keep spores and dust off skin and clothing and out of vehicles. Hooded and booted versions are used where overhead work or heavy debris is expected.

See also: PPE by Condition

Critical barrier

Engineering controls

The sheeting and tape that seal doors, vents, penetrations and openings so air only moves where you intend it to. Critical barriers are what make negative pressure achievable in the first place.

See also: Containment types explained

Cross-contamination

Methods

Spreading contamination from the work area into clean space via air, foot traffic, tools or contents. Containment, decon procedure and equipment cleaning exist almost entirely to prevent it.

See also: Containment types explained

D

Daily log

Verification & documentation

The day-by-day record of work performed, crew on site, equipment running, readings taken and any change in conditions. It turns a project into a defensible file instead of a memory.

See also: Documentation on a mold job

Damp wiping

Methods

Wiping non-porous and semi-porous surfaces with a detergent solution to lift contamination the vacuum leaves behind. Cloths are changed frequently so you are removing material rather than redistributing it.

See also: Mold remediation checklist

Decontamination chamber

Engineering controls

The attached anteroom where workers don and doff PPE so contamination is not tracked into clean space. On larger jobs it is built in stages with bagging and clean-side storage separated.

See also: Containment types explained

Detail cleaning

Methods

The systematic top-to-bottom HEPA vacuuming and wiping of every surface in the work area after removal is finished. It is the step that decides whether verification goes smoothly or you come back.

Dew point

Moisture

The temperature at which air becomes saturated and moisture condenses out. Any surface colder than the dew point will collect water, which is how cold-side framing and ductwork end up growing mold.

See also: Moisture control

Doffing

PPE

Removing PPE inside the decon chamber, rolling contaminated surfaces inward and bagging them, with the respirator coming off last. Careless doffing undoes everything the containment achieved.

See also: PPE by Condition

Donning

PPE

Putting PPE on in the correct order, on the clean side of the decontamination chamber, with a seal check on the respirator before entering. Order matters because it determines whether the seal survives.

See also: PPE by Condition

Double bagging

Methods

Sealing contaminated debris in one bag, wiping or bagging it again in the decon chamber, then carrying it out. It keeps the removal route from becoming the contamination route.

See also: Mold remediation checklist

Dry standard

Moisture

The moisture reading taken from unaffected material of the same type in the same building. It becomes the target the affected material has to reach before the job is considered dry.

Drying

Methods

Bringing affected materials back to a documented dry standard after removal and cleaning. Mold work is not finished when the growth is gone — it is finished when the materials and the air are dry.

E

Encapsulant

Methods

The coating product used in encapsulation. Applying it over uncleaned growth hides the problem instead of solving it, and it is one of the clearest signs of a job done badly.

Encapsulation

Methods

Applying a coating over a surface after it has been properly cleaned, usually to seal residual staining or bind remaining dust. It is a finishing step, never a substitute for removing growth.

See also: Attic mold remediation

Engineering controls

The physical measures that keep contamination inside the work area — barriers, negative pressure, HEPA filtration and controlled airflow. They protect occupants and crew without relying on anyone remembering a procedure.

See also: Containment types explained

Equilibrium moisture contentEMC

Moisture

The moisture level a material settles at when left in a given temperature and humidity. Materials do not dry below the EMC of the surrounding air, which is why controlling the space controls the drying.

See also: Moisture control

Eye protection

PPE

Non-vented or indirectly vented goggles worn with half-face respirators to keep dust and splashes out of the eyes. A full-face respirator covers this requirement in one piece of equipment.

See also: PPE by Condition

F

Fit test

PPE

The test that confirms a tight-fitting respirator actually seals to a specific worker's face. It is required before that worker relies on the respirator, and it is repeated on the schedule the regulation sets.

Full containment

Engineering controls

A sealed work area with negative pressure, HEPA-filtered exhaust and an attached decontamination chamber for entry and exit. It is the standard approach for larger Condition 3 areas and occupied buildings.

See also: Containment types explained

Full-face respirator

PPE

A tight-fitting respirator covering the entire face, protecting the eyes as well as the airway. It is chosen for heavier contamination, irritating products or work where debris is likely to fall.

See also: PPE by Condition

Fungal fragments

Microbiology

Broken pieces of hyphae and spores small enough to stay airborne for long periods. Fragments are part of what containment and HEPA filtration are designed to capture, and part of why aggressive dry demolition is avoided.

Fungi

Microbiology

The kingdom of organisms that includes molds, yeasts and mushrooms. Fungi feed by breaking down organic material, which is exactly why they colonize damp drywall paper, wood framing and dust inside buildings.

See also: Mold biology basics

G

GPPGrains per pound

Moisture

A measure of the actual weight of moisture carried in a pound of dry air. Unlike relative humidity, GPP does not move when temperature alone changes, so it shows whether air is genuinely drier.

H

Half-face respirator

PPE

A tight-fitting elastomeric respirator covering nose and mouth, fitted with particulate cartridges. It offers more protection than a filtering facepiece but leaves the eyes needing separate protection.

See also: PPE by Condition

HEPAHigh-efficiency particulate air

Engineering controls

A filtration rating for capturing very fine particles, used in vacuums, air scrubbers and negative air machines. HEPA filtration is what makes it acceptable to exhaust work-area air at all.

HEPA vacuuming

Methods

Vacuuming surfaces with a HEPA-filtered machine to capture settled spores, dust and debris. It is a source-removal step used before, during and after cleaning, not a finishing touch.

See also: Mold remediation checklist

HVAC isolation

Engineering controls

Shutting down and sealing the heating and cooling system serving a work area so it cannot distribute spores through the building. Skipping it can turn a one-room job into a whole-house job.

Hydrophilic fungi

Microbiology

Molds that need consistently wet materials to grow. Finding them usually points to a chronic leak or standing water rather than seasonal humidity, which changes both the scope and the moisture correction.

HygrometerThermo-hygrometer

Moisture

The instrument used to read temperature and relative humidity, and to calculate dew point and grains per pound. Readings inside containment, outside it and outdoors are logged to show conditions were controlled.

See also: Documentation on a mold job

Hyphae

Microbiology

The thread-like filaments that make up a mold colony and push into the material it grows on. Because hyphae penetrate porous substrates, wiping a surface rarely removes growth from drywall or insulation.

See also: Mold biology basics

I

IAC2International Association of Certified Indoor Air Consultants

Certification & licensing

An organization offering indoor air quality and mold inspection certifications, commonly held alongside home inspection credentials. It is independent of the IICRC, and its eligibility and renewal requirements are published by IAC2 rather than by any standards body.

See also: Mold inspector certification

IEPIndoor Environmental Professional

S520 & standards

The person who assesses the building, defines the extent of contamination and writes the protocol the remediator follows. Ideally the IEP is independent of the remediation contractor so the clearance decision carries weight.

See also: Mold inspector certification

IICRCInstitute of Inspection, Cleaning and Restoration Certification

Certification & licensing

The nonprofit body that develops restoration standards and issues technician certifications, including AMRT and the S520 mold standard. It certifies people and firms; it does not license contractors.

M

Makeup air

Engineering controls

The air that flows into containment to replace what the negative air machine exhausts. Without a controlled inlet the containment either collapses inward or pulls air from places you did not intend.

Manometer

Engineering controls

The instrument used to read the pressure differential across a containment barrier. Logging manometer readings through the job turns 'we had negative pressure' into something you can show later.

See also: Documentation on a mold job

May

S520 & standards

Wording that describes an allowable option with no obligation attached. A may statement tells you a method or material is acceptable in the right circumstances, leaving the choice to the person running the project.

See also: IICRC S520 explained

Media blasting

Methods

Using a propelled medium such as soda or dry ice to strip growth off framing and sheathing. It is fast on large timber areas but produces significant debris that has to be contained and cleaned up.

See also: Attic mold remediation

Medical clearance

PPE

The medical evaluation a worker completes before wearing a respirator, confirming they can do so safely. It comes before fit testing and is part of the employer's written respiratory protection program.

Moisture contentMC

Moisture

How much water a material holds, read with a moisture meter and compared against a dry standard from unaffected material of the same type. It is the number that tells you whether drying is finished.

Moisture log

Verification & documentation

The running record of moisture readings by location and date, including the dry standard used. It is how you prove materials reached dry rather than simply looking dry on the last day.

See also: Documentation on a mold job

Moisture meter

Moisture

A pin or pinless instrument used to compare suspect materials against a known dry reference. Pinless units scan quickly for mapping; pin meters confirm depth and give a defensible reading for the file.

Moisture source correction

Moisture

Fixing the leak, drainage failure or humidity problem that caused the growth. Without it, remediation is temporary — this is the step that separates a finished job from a callback.

See also: Moisture control

Mold

Microbiology

The common name for filamentous fungi that grow as visible colonies on damp organic surfaces. Mold needs moisture, a food source and workable temperatures — remove the moisture and the growth stops.

See also: Mold biology basics

Mold assessor

Certification & licensing

The role that inspects, samples and writes the protocol, kept separate from the remediation role in several state programs. The IICRC does not license assessors; states and independent bodies handle that credential.

See also: Mold inspector certification

MRSMold Remediation Specialist

Certification & licensing

An IICRC designation aimed at people directing and supervising mold projects rather than only performing the field work. Requirements and prerequisites are published by the IICRC.

MVOCMicrobial volatile organic compound

Microbiology

A gas given off by active microbial growth and the usual reason a building smells musty before anything is visible. An MVOC odor is a prompt to look for hidden moisture, not a measurement of contamination.

Mycelium

Microbiology

The mass of hyphae that forms the body of a fungus. When you see fuzzy growth spreading across the back of drywall or joist faces, you are looking at mycelium rather than individual spores.

See also: Mold behind drywall

Mycotoxin

Microbiology

A toxic compound some molds produce under certain conditions. Mycotoxins are one reason source removal beats killing growth in place, since dead material can still carry the compounds and the fragments.

See also: Mold biology basics

N

N95

PPE

A filtering facepiece respirator that removes most airborne particles when it seals properly. It is the entry-level respiratory protection for limited mold work and still requires fit testing and a written program.

See also: PPE by Condition

Negative air machineNAM

Engineering controls

An air filtration device set up to exhaust filtered air out of the containment, pulling the work area negative relative to the rest of the building. Sizing it correctly is a matter of volume and target air changes.

Negative pressure

Engineering controls

Keeping air pressure inside containment lower than the surrounding space so air flows inward and leaves only through HEPA filtration. It is the single most important control for protecting the rest of the building.

Nitrile gloves

PPE

Chemical-resistant disposable gloves used for mold cleaning and product handling. Longer cuffs are taped to coverall sleeves so no skin is exposed at the wrist during dirty work.

See also: PPE by Condition

Non-porous material

Methods

Material such as glass, metal, hard plastic and finished tile that mold sits on but cannot grow into. These surfaces are almost always cleaned and kept rather than removed.

See also: Mold remediation checklist

Non-viable

Microbiology

Describes spores and fragments that are no longer alive but still present. Non-viable particles still matter for exposure and for clearance sampling, which is why remediation removes material rather than only killing it.

See also: PRV and clearance

Normal fungal ecology

S520 & standards

The background fungal load you would expect in a comparable clean indoor space. Every building has spores in the air and on surfaces; the point of remediation is returning to that background, not eliminating fungi.

NORMINational Organization of Remediators and Mold Inspectors

Certification & licensing

A membership and training organization offering mold inspection and remediation certifications and continuing education. Like ACAC, it is independent of the IICRC, sets its own eligibility rules, and publishes its own renewal requirements — confirm those with NORMI directly.

See also: Mold inspector certification

P

P100 filter

PPE

A high-efficiency particulate cartridge used on half- and full-face respirators. P100s are the usual choice for mold work because they capture spores and fragments and are not oil-sensitive.

See also: PPE by Condition

Pack-out

Methods

Removing contents from the work area for cleaning and storage off site. Documenting condition and location before anything moves protects both the customer and the contractor.

See also: Documentation on a mold job

PAPRPowered air-purifying respirator

PPE

A battery-powered blower that pushes filtered air into a hood or facepiece. Loose-fitting versions suit workers with facial hair or those who cannot pass a tight-fit test, and they are cooler over long shifts.

See also: PPE by Condition

Parasite

Microbiology

An organism that lives on or in a host and may be present in sewage-contaminated water. Parasites sit alongside bacteria and viruses in the contaminant list that drives Category 3 handling requirements.

See also: Category 3 sewage remediation

Penicillium

Microbiology

A widespread indoor mold genus associated with damp building materials and stored goods. Lab reports often group it with Aspergillus because the spores cannot be told apart by direct microscopy.

See also: Mold biology basics

Photo documentation

Verification & documentation

Dated photographs of pre-existing conditions, containment, removal, cleaning and final condition. Photos are the cheapest insurance on a mold job and the first thing anyone asks for afterwards.

See also: Documentation on a mold job

Poly sheeting

Engineering controls

The plastic film used to build containment walls, ceilings and critical barriers. Thickness is chosen for the job — heavier film for walls and traffic areas, lighter for covering surfaces and contents.

Porous material

Methods

Material such as drywall, ceiling tile, carpet pad and fibrous insulation that mold can grow into. Once contaminated, these are generally removed and discarded rather than cleaned.

See also: Mold behind drywall

Post-remediation verificationPRV

Verification & documentation

The process of confirming the work succeeded before demobilizing: visual inspection, checking that materials are dry, and any sampling the protocol calls for. Passing PRV is what closes out a mold project.

See also: PRV and clearance

PPEPersonal protective equipment

PPE

The respirators, suits, gloves and eye protection worn to limit exposure to mold, dust and cleaning products. Selection scales with the Condition, the contaminant and the work being performed.

See also: PPE by Condition

Pre-filter

Engineering controls

The coarse filter that catches large dust and debris before air reaches the HEPA element. Changing pre-filters on schedule is the cheapest way to protect airflow and extend HEPA filter life.

Pressure differential

Engineering controls

The measured difference in air pressure between the containment and the adjacent clean area. Measuring it — rather than watching the poly flutter — is what proves the containment is actually working.

Principles of mold remediation

S520 & standards

The core sequence every mold job follows: protect health and safety, document conditions, control the contaminant, physically remove the contamination and correct the moisture problem that caused it.

See also: IICRC S520 explained

Psychrometry

Moisture

The study of air and its moisture properties — temperature, humidity, dew point and vapour pressure. Mold work uses it to judge whether conditions will let materials dry or keep feeding growth.

R

Reciprocity

Certification & licensing

Whether one state accepts a licence or credential issued by another. It varies widely in mold programs, so a licence in one state should never be assumed to travel — confirm with the receiving agency.

See also: Mold licensing by state

Reference guide

S520 & standards

The companion material that explains the reasoning behind a standard. A reference guide gives background, examples and detail, but it does not create requirements the way the standard itself does.

See also: IICRC S520 explained

Relative humidityRH

Moisture

The amount of moisture in the air compared with the maximum that air could hold at its current temperature. RH shifts with temperature alone, so it is read alongside dew point rather than on its own.

See also: Moisture control

RemediationMicrobial remediation

Methods

The controlled process of removing mold contamination, cleaning affected surfaces and correcting the moisture source so the space returns to a normal fungal ecology. Removal, not disinfection, is the core of it.

Remediation protocol

S520 & standards

The written instructions from the assessor describing what has to be removed, cleaned, contained and verified. The protocol defines the outcome; the contractor's scope of work describes how that outcome will be delivered.

Remediation work plan

S520 & standards

The project-specific document written before work starts that sets out sequence, containment design, PPE, monitoring and verification. It is the plan the crew works from and the record a reviewer reads afterward.

See also: Mold remediation checklist

Remediator

S520 & standards

The contractor or technician who performs the physical mold work: containment, source removal, cleaning and drying. The remediator executes the protocol; assessing the building and clearing it are separate roles.

Required CFM

Engineering controls

The airflow needed to hit a target number of air changes in a given containment volume. Work it out before you load the truck rather than guessing from how many machines fit through the door.

Respiratory protection program

PPE

The employer's written program covering respirator selection, medical evaluation, fit testing, training, maintenance and recordkeeping. Handing out respirators without one is a common compliance failure on mold jobs.

S

S520ANSI/IICRC S520 Standard for Professional Mold Remediation

S520 & standards

The consensus industry standard describing how professional mold remediation should be planned, contained, performed and verified. It is the document the AMRT exam is written from, and the source of the Condition 1/2/3 language remediators use on every job.

See also: IICRC S520 explained

Scope of work

S520 & standards

The contractor's written description of the areas, materials, methods and engineering controls included in the project. A clear scope is what keeps change orders, clearance disputes and occupant expectations under control.

Semi-porous material

Methods

Material such as wood framing, concrete and masonry that can often be cleaned by HEPA vacuuming, damp wiping or abrasive methods. Extent of penetration decides whether it stays or goes.

See also: Attic mold remediation

Shall

S520 & standards

In standards language, a mandatory requirement. When a document says a remediator shall do something, that step is not optional and deviating from it is a departure from the standard rather than a judgment call.

See also: IICRC S520 explained

Should

S520 & standards

In standards language, a recommendation rather than a requirement. A remediator can deviate from a should when the situation justifies it, but the reasoning belongs in the file so the decision can be defended later.

See also: IICRC S520 explained

Source containmentLimited containment

Engineering controls

A small barrier built directly around a localized work area, typically without a full decontamination chamber. It suits small, well-defined jobs where the crew is in and out quickly.

See also: Containment types explained

Source removal

Methods

Physically removing contaminated material and the growth on it rather than trying to kill it in place. It is the central principle of professional mold remediation and the reason spraying alone is not remediation.

Spore

Microbiology

The microscopic reproductive unit a mold releases to spread. Spores are present in normal indoor and outdoor air, travel easily on air currents and clothing, and are the particle containment is designed to hold.

See also: Mold biology basics

Spore trap

Verification & documentation

The cassette an air sample is drawn through so spores land on a slide for counting under a microscope. It reports both viable and non-viable particles, which is why it is common for clearance.

See also: PRV and clearance

Stachybotrys chartarum

Microbiology

The mold most often called black mold in the press. It favours chronically wet cellulose materials like drywall paper, and its presence signals a long-running moisture problem rather than a one-off spill.

See also: Mold biology basics

StandardConsensus standard

S520 & standards

A document developed through a formal consensus process that sets out what practitioners are expected to do. Standards use shall and should language and are treated as the benchmark a competent contractor is measured against.

See also: IICRC S520 explained

Standard of care

S520 & standards

The level of work a competent, qualified remediator is expected to deliver on a similar project. In mold work the published standard is widely treated as that benchmark, which is why departures need documentation.

See also: IICRC S520 explained

State mold license

Certification & licensing

A government permission to perform mold assessment or remediation for compensation in a given state. A license is issued by a state agency; a certification is issued by a private body — they are not interchangeable.

See also: Mold licensing by state

Surface sampling

Verification & documentation

Collecting material from a surface to identify what is growing or settled there. It answers what is present at that spot, not how much is in the air, so it complements rather than replaces air sampling.

See also: PRV and clearance

Swab sample

Verification & documentation

A surface sample collected with a sterile swab, often used on irregular or textured surfaces where tape will not sit flat. Results identify what is present rather than quantify airborne exposure.

See also: PRV and clearance

T

Tape lift

Verification & documentation

A surface sample taken by pressing clear adhesive onto a surface and sending it to a laboratory. It is quick and cheap for confirming whether visible staining is actual fungal growth.

See also: PRV and clearance

Thermal imaging camera

Moisture

A camera that shows surface temperature differences, often revealing where moisture may be hiding. It points you to the spot; a moisture meter is what confirms whether the material is actually wet.

V

Vapor barrier

Moisture

A material that strongly resists moisture moving through an assembly as vapour. Used correctly it keeps damp air out of a crawlspace or wall cavity; used on the wrong side it traps moisture and feeds growth.

Vapor retarder

Moisture

A material that slows, rather than stops, vapour movement through an assembly. The distinction matters when you are deciding whether a wall or crawlspace can dry toward the inside after a mold job.

Viable

Microbiology

Describes spores or fragments that are still alive and capable of growing if given moisture. Culture-based lab methods report viable organisms, which is only part of what is present in a contaminated space.

See also: PRV and clearance

Virus

Microbiology

An infectious agent that can be present in grossly contaminated water. Viruses are one reason Category 3 work uses stricter PPE, stricter containment and disposal of affected porous materials.

See also: Category 3 sewage remediation

Visual inspection

Verification & documentation

The walkthrough confirming no visible growth, no visible dust or debris, and no remaining moisture problems before release. It is the first and most important part of verification, before any sample is taken.

See also: PRV and clearance

W

Waste manifest

Verification & documentation

The record of what contaminated material left the site and where it went. On most mold jobs debris is ordinary construction waste, but the disposal record still belongs in the project file.

See also: Documentation on a mold job

Water activityAw

Microbiology

A measure of how much water in a material is actually available to microorganisms. Water activity, not just moisture content, determines whether a given surface will support fungal growth.

See also: Moisture control

WRTWater Damage Restoration Technician

Certification & licensing

The IICRC certification covering water categories, drying principles and restoration fundamentals. It is the prerequisite for AMRT, so the mold class assumes you already understand moisture behaviour.

X

Xerophilic fungi

Microbiology

Molds able to grow where relatively little water is available. They are often the first colonizers on a slightly damp surface, appearing long before a material is wet enough to read obviously on a meter.

See also: Moisture control

Z

Zipper doorZip wall / zipper access

Engineering controls

An adhesive zip strip installed in poly sheeting to create a sealable entrance. It lets crews pass in and out without cutting new openings and re-taping the barrier each time.

See also: Containment types explained

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