Q:         My asbestos report says that I have 3% Chrysotile. What percentage is the limit so that I don't have to contact an abatement contractor?
A:         The OSHA limit is 0.1%, therefore you need trained workers with protective equipment to remove the asbestos. The percentage of asbestos is really not significant - it is still asbestos-containing at 0.01% or 90% - either way it is dangerous.

Q:         I've been told that I need to test my linoleum/carpet/ceiling tested for asbestos before having it removed. Why?
A:         Any contractor with workers must follow OSHA rules. OSHA requires that no employee be exposed to asbestos. If the home was built prior to 1980, there is a high likely hood that the materials used are asbestos. Linoleum (trade name) or Resilient Sheet Flooring, Carpet Glue, Floor Tile, Floor Tile Mastic, "Pop Corn" Ceiling material, Wallboard/Joint Compound, etc. are all products that typically contain asbestos.

Q:         If I have already removed my linoleum/carpet/ceiling, should I have it tested for asbestos anyways?
A:         A little late at this point. If it was removed by a non-asbestos removal professional, you may have created an air quality issue for you and those workers. To bring a little piece of mind, you might want to test the air. If it is positive, then it would make sense to have a professional asbestos abatement company come in and perform an environmental clean of the area.

Q:         How many samples should I take?

A:         The more the samples, the greater chance to prove or disprove the presence of asbestos. We suggest at least three (3) samples, at a minimum two (2).

Q:         I just received my lead report. What does it mean?

A:         Consult with the Department of Health Services. However, the HUD Guidelines "action levels" for Paint are 0.5% by weight = 5,000 ppm by Atomic Absorption Spectroscopy (AA) or 1.0 mg/cm2 by XRF.  Soils: EPA TSCA Section 403 Standard - January 2001 are > 400 ppm Hazardous in play areas. > 1,200 ppm Bare soil yard wide average. California Title 17 "Lead Contaminated Soil" - ≥ 400 - 1000 ppm Hazardous in bare soil in areas where children play. > 1,000 ppm Hazardous in all other areas.  Water: 15 ppb: US EPA "Action Level"

Q:         I have black mold growing on my wall(s). How dangerous is it?

A:         That depends on you or others in the home. Each of us react differently to molds. All molds are allergens. Some molds have mycotoxins that are harmful. You should consult with a doctor trained in this area.

Q:         I think I have mold, should I be worried?

A:         Yes, it may be a sign that water is making its way into the building envelope either from a faulty roof, water intrusion, condensation or a damaged pipe.

Asbestos Terms


The process of treating asbestos to reduce or remove its hazard potential. The three methods of abatement are removal, or taking the asbestos out; encasement, which is enclosing the asbestos behind or within an impermeable covering, and encapsulation, which is a process of "binding" the asbestos material with a liquid which subsequently dries and forms a "shell." Of the three methods, only removal is permanent!


Asbestos Hazard Emergency Response Act. Promulgated under TSCA, this regulation required schools (k-12 public and private non-profit) be inspected for asbestos. It also established training requirements for workers who would remove asbestos from the schools, and created the framework for Local Education Agencies (LEA's) to establish asbestos Management Plans. A subsequent rule, ASHARA, established that asbestos related work performed in public and commercial buildings would be performed by personnel whose training meets the AHERA requirements.

Air Monitoring

Collecting samples of air for the purposes of determining the quantity of airborne fibers. Depending upon the method of analysis, either all fibers are counted, or only asbestos fibers. Air samples are collected either in the breathing zone of workers (personal air samples) or in large areas. During an abatement project it is customary to have air samples taken outside the work area to ensure and document that the asbestos fibers did not migrate to unprotected areas.


A generic name given to a number of naturally occurring hydrated mineral silicates that possess a unique crystalline structure, are incombustible in air, and are separable into fibers. Asbestos includes the asbestiform varieties of chrysotile (serpentine), crocidolite (riebeckite), amosite (cummingtonite-grunerite), anthophyllite, actinolite, and tremolite.

Asbestos "Bulk" Sampling

Taking samples of materials to determine whether nor not it contains delectable asbestos. The EPA recommended method for analysis is Polarized Light Microscopy.

Certified Asbestos Consultant (CAC)

In California, an individual who by virtue of training, experience and passing a state administered test is certified to perform asbestos consulting activities.

Chain of Custody (COC)

A formal procedure for tracking samples and ensuring their integrity.

Clearance Inspections and Clearance Monitoring

After an abatement action has taken place, it is prudent to have the work area inspected by an person independent of the contractor. This clearance inspection should be visual and tactile in nature, and should ensure that no residual asbestos fibers are remaining. Following the successful visual/tactile inspection, air monitoring should be performed to determine that the airborne fiber concentration within the removal area is less than or equal to the ambient (i.e., outside) air.

Friable Asbestos

Asbestos containing material which can be crumbled to dust when dry, under hand pressure.

HEPA Filter

High Efficiency Filter Absolute - capable of capturing 99.97% of fibers at the 0.3-micron size range. This filter is used during abatement and clean-up activities to ensure that asbestos fibers are captured and not spread into the environment.

Phase Contrast Microscopy (PCM)

Method of analysis for air samples which is required by OSHA for the determination of exposures to workers. The method does not distinguish asbestos from non-asbestos fibers. Engineering controls and personal protective equipment (PPE) for workers performing asbestos related work are triggered by the results of PCM air samples. Sometimes this method of analysis is used for post abatement monitoring, particularly for projects preceding demolition of structures. In order to pass a project using PCM, the result(s) must be less than 0.01 fibers per cubic centimeter (f/cc).

Point Counting

If the PLM lab results show less than 1% (< 1%) it is subject to the OSHA regulation which states that a workman can not be exposed to construction material that contains greater than one tenth of one percent (0.1%). If the PLM sample results are reported as < 1% it still may mean that the sample is greater than 0.1%. Due to the limitations of the PLM, a Point Count is recommended for those samples that fall into this category of greater than 0.1% and 1%.

Polarized Light Microscopy (PLM)

EPA recommended method for analyzing materials for the presence of asbestos. The method is often supplemented with techniques to remove other physical and chemical components of the sample and thus make the asbestos more readily visible. EPA maximum allowable asbestos in a bulk sample is less than 1%. If the sample is 1% or greater, it is considered an Asbestos Containing-Material (ACM) and must be removed by a licensed asbestos removal contractor and disposed of in an EPA Class II hazardous dump.

Project Management

During abatement it is often prudent to have a professional representing the interests of the building owner to oversee the project.


Guidelines which a contractor will follow in removing or otherwise abating asbestos containing materials. In California asbestos specifications are written by Certified Asbestos Consultants.

Transmission Electron Microscopy (TEM)

Using a powerful electron beam microscope, it is possible to distinguish asbestos from other fibers which have been collected during air monitoring. AHERA requires this method for determining if a school is "clean" after an asbestos abatement action. Another TEM method, Yamate II, is more stringent than AHERA because it does not limit the size of fiber which is counted. Yamate II is often the method of choice for analysis in occupied buildings other than schools. The EPA requires that results be less than 70 structures per millimeter squared (s/mm2) to pass a school project.

Lead Terms


The process of treating lead pain t to reduce or remove its hazard potential. The three methods of abatement are removal, or taking the lead off the surface; encasement, which is enclosing the lead paint behind or within an impermeable covering, and replacement which is the process of removing the building component and replacing it with a new piece.

Air Monitoring

Collecting samples of air for the purposes of determining the quantity of lead dust. Air samples are collected either in the breathing zone of workers (personal air samples) or in large areas. During an abatement project it is customary to have air samples taken outside the work area to ensure and document that the lead dust did not migrate to unprotected areas.

Atomic Absorption (AA)

The method of analysis used to determine the percent of lead in paint chips, dust samples, soil and water. This is a laboratory (as opposed to field) method. The results are reported in parts per million (ppm) and/or in % lead for amount of material tested.

Chemical Symbol


Clearance Sampling

After a lead abatement action, it is customary (required by HUD) to take wipe samples of measured areas of the room to determine the residual levels of lead. The samples are analyzed by atomic absorption, and results are reported in micrograms per square foot. The current EPA recommendations for clearance are: Uncarpeted Floors - 10 µg/sq. ft.  Interior Window sills - 100 µg/sq. ft.  Window Troughs, wells - 400 µg/sq. ft.


Housing and Urban Development; the Federal agency which is currently in charge of public housing. HUD has published guidelines for the testing and risk assessment of lead in public housing, aimed toward reducing lead poisoning primarily in children and women of child bearing potential.

Naturally occurring mineral which has been proven to have severe health effects if breathed or ingested. Only tetraethyl lead (i.e., the kind of lead used in gasoline) is known to be readily absorbed by the skin.

Lead Based Paint

Paint (also putties, glazes and other surface coatings) which contain a "dangerous" amount of lead. Under current regulations paint with greater than 600 parts per million is no longer manufactured for household use, but it is still available for marine and other exterior use.

Lead Inspection

The process of inspecting a building or dwelling to determine the presence of lead in the painted surfaces. The determination of "lead" is different for HUD than it is for OSHA. HUD defines "lead paint" as having greater than 1 microgram per square centimeter of surface or .5% by weight; OSHA has no threshold limit: any delectable lead in a paint makes it lead paint as far as worker exposures are concerned. Lead inspections are performed by XRF, paint chip analysis, or a combination of both.

It is considered a lead-based paint and a hazard if disturbed if it contains lead as follows:

    • 0.5% by weight or 5,000 ppm (parts per million) or 1.0 mg/sq. cm (milligrams per centimeter squared)

Considered to be lead contaminated if:

    • It is 400 ppm or greater in children's play areas
    • It is between 400 ppm and 1,000 ppm in bare ground areas in a yard
    • It is 1,000 ppm in any bare ground area.

Lead in the air comes under OSHA regulations for workers.

    • 50 µ/sq. meter (micrograms per meter squared) This is called the personal exposure limit with an 8-hour time weighted average (TWA).
    • 30 µ/sq. meter is the OSHA "Action Level" (at this point you must start protection procedures).


Lead content in dust is regulated by two (2) sources:

    • EPA, TSCA (Toxic Substance Control Act), their limits are as follows:
      • Equal to or greater than (> =) 40 µg/sq. feet floors
      • >= 250 µg/sq. feet window sills.
    • California Title 17
      • >= 50 µg/sq. feet for interior floor surfaces
      • >= 250 µg/sq. feet for interior horizontal window surfaces
      • >= 800 µg/sq. feet for exterior floor and exterior horizontal window surfaces.


Lead in water is regulated by the US EPA and an action level of 15 ppb (parts per billion).


As stated XRF is recorded in the field and the maximum allowable lead in paint is less than 1.0 mg/sq. centimeters (milligrams per centimeter squared).

California OSHA (Cal/OSHA), Federal OSHA, EPA, DHS, DOSH regulations require lead sample collection, XRF contractors & workers and consultant monitors and supervisors be certified by the department of health services (DHS) and OSHA.

Project Management

During abatement it is often prudent to have a professional representing the interests of the building owner to oversee the project.

Guidelines for a contractor to following in removing or otherwise disturbing lead paint.

Mold Terms

Source: Soil, dead organic debris, hay, food. Also reported from wet building materials. Considered as indicator of extra moisture conditions.  Harmful Effects to Humans: Allergy type I (Hay fever, asthma, Humidifier Lung).

Source: Soil, dead organic debris, food, textiles. Plant pathogen, most commonly found on weakened plants, house dust, carpets, damp spots around showers and window frames, any areas of condensation. Harmful Effects to Humans: Allergy types I and type III (Hay fever, asthma Woodworker's Lung, Apple store hypersensitivity, Chronic Sinusitis). Some species are known to produce mutagenic toxins. May cause skin and nail infection. Deep infections are reported from sensitive persons.

Source: Soil and decomposing plant material. Harmful Effects to Humans: One species, Arthrinium sphaerospermum, reported as an allergen.

Source: This is a group of over 3000 fungal genera producing ascospores as a result of sexual reproduction. These spores are liberated in high moisture conditions.  Parasitic on plant parts or Saprophytic on decaying cellulose rich substrates and on building materials. These spores are variable in shape and size based on fungal genus. Some common ascospores are from Xylaria, and Peziza like macro fungi, which may be growing around or indoor underneath the carpet. Presence of numerous ascospores may be considered as indicative of high moisture conditions.  Harmful Effects to Humans: Highly variable, depends on genus and species, and on health conditions of occupants inside the building. It may vary from Allergy to Toxicity and human infection. If any specific types of ascospores are reported in large numbers than attention should be paid for advanced identification. Many species are known to be responsible for damaging building material.

Source: Cosmopolitan genus with approximately 200 known species. Soil, decaying plant debris, compost piles, stored grain, water-damaged building materials. Due to rapid multiplication of spores produced in large numbers, this group is difficult to manage in water damaged buildings. A. versicolor is most frequently reported species from wet cellulose rich surfaces inside the building and from air and from dust accumulations. Indicator of moisture conditions. Harmful Effects to Humans: Hay fever, asthma, allergic bronchopulmonary aspergillosis, allergic fungal sinusitis, Humidifier lung, Malt worker's lung, Compost lung, Wood trimmer's disease, straw hypersensitivity, Farmer's lung, Oat grain hypersensitivity. A. fumigatus is most common species known to cause fungus ball, invasive infection, sinusitis and bronchopulmonary aspergillosis. A, niger is common species, a frequent agent of aspergilloma able to cause swimmers' ear and invasive disease. A. flavus is rare species but can cause nasal and sinus infections. Produces aflatoxin which is a potential human carcinogen. A. versicolor is most frequently reported species from indoor buildings and is rarely a cause of infection in humans.

Source: Saprophytes and plant pathogens (including mushrooms and other macro fungi), gardens, forests, woodlands. They are spores produced from a group of fungi called Basidiomycetes. These may be parasitic on plants (Rusts and Smuts) or saprophytic on decaying woods, dung and soil (Mushrooms). Many of them cause white and brown rot of wood. Serpula lacriman (old name Poria incrassata) is well known aggressive agent of dry rot causing rapid destruction of structural wood of buildings and is always a major concern for construction engineers.  Harmful Effects to Humans: Hay fever, asthma, lycoperdonosis (puffball spores), mushroom culture hypersensitivity. Mushroom toxicosis in case of ingestion of poisonous mushrooms. Some yeasts are basidiospore producers and may cause opportunistic infection in humans.

Source: This is a group of spores similar in morphology. Plant debris and soil. Plant pathogens of numerous plants, particularly grasses. Harmful Effects to Humans: Bipolaris is occasionally reported for causing different types of phaeohyphomycosis from normal and from immunosensitive patients. Hay fever, asthma, allergic fungal sinusitis.

Source: Soil, stored and transported fruit and vegetables. Plant pathogen and saprophyte on flowers, leaves, stems, fruit. Harmful Effects to Humans: Hay fever, asthma, Winegrower's Lung.

Source: Parasite of higher plants, causing leaf spot. Harmful Effects to Humans: Not studied.

Source: Soil, seeds, cellulose substrates (causes wood decay), dung, woody and straw materials, water-damaged sheetrock and paper materials. Harmful Effects to Humans: Hay fever, asthma, skin and nail infections, A few species may cause Onychomycosis. A few species may cause opportunistic invasive disease.

Source: Soil of many different types, plant litter, plant pathogen, leaf surfaces, old or decayed plants, shower curtains, dirty refrigerators, moist window frames, generally, damp environments, often discoloring indoor paint, paper, and textiles. A few species can be considered as indicator of excessive moisture conditions inside the building.  Harmful Effects to Humans: Hay fever, asthma, Hot Tub Lung, moldy wall hypersensitivity. Rarely cause chronic subcutaneous infection.

Source: Plant debris, soil, facultative plant pathogens of tropical or subtropical plants. Harmful Effects to Humans: Hay fever, asthma, allergic fungal sinusitis, mycotic keratitis, corneal infections.

Source: Plant debris, soil, textiles, paper products. Secondary invader of damaged plant tissue, cosmopolitan, Common on water damaged dry wall and wood products. Harmful Effects to Humans: Hay fever, asthma, skin infections.

Source: Soil, saprophytic or parasitic on plants. Many species are important plant pathogens, requires extremely wet conditions, often in humidifiers and in buildings with water intrusion. Harmful Effects to Humans: Hay fever, asthma.  A few species produce toxins, which may be harmful to sensitive persons.

Hyphal Fragments

Source: They are filamentous septate or aseptate vegetative structures of molds where spores are born in characteristic patterns. Identification of major groups of fungi is based on the morphology of hyphae. Harmful Effects to Humans: Presence of hyphae on a bulk surface may indicate the possibility of mold growth and production of more spores on the suspected surface. Hyphal growth is initial major component of colony forming units in viable cultural analysis of molds that confirms the presence of mold growth on a culture plate.

Source: Plant litter, soil, many types of plants and trees. From chronically wet cellulose rich substrates. Harmful Effects to Humans: Recently reported as toxinogenic. Some researchers consider this as species of Stachybotrys echinata.

Source: These are not true molds and are commonly called as slime molds. Decaying logs, stumps and dead leaves, particularly in forested regions.  Reported from football grounds and can be a concern for players.  Harmful Effects to Humans: Hay fever, asthma.

Source: Decaying plant material and soil. Common in outdoor environment. Harmful Effects to Humans: Hay fever, asthma.

Source: These are plant pathogens also called mildew. Spores are common in outdoor environments. Harmful Effects to Humans: Not well known.

Source: Large group of around 200 species. Cosmopolitan in nature.  Soil, decaying plant debris, compost piles, fruit rot, spoiling food and milk products. Associated with indoor wall checks, aerosols, carpet, wallpaper, and interior fiberglass duct insulation, P. glabrum has been isolated from diesel fuel.  Harmful Effects to Humans: Hay fever, asthma, Cheese washer's lung, Woodman's lung, moldy wall hypersensitivity. Many species produce toxins and other volatile microbial compounds with pharmaceutical importance. Some species are known to cause type I and type III allergy to sensitive persons. P. marneffi is only known species from Asia which may cause human infection.

Source: Common on dead leaves of more than 50 different plants, especially leaf fodder. Soil, grasses. Harmful Effects to Humans: Common in outdoor environment.  No cases are known from humans or animals.

Source: This is common mold found associated with spoiling food, decaying fruits and vegetables and dung. Also plant pathogenic. Harmful Effects to Humans: Primary cause of Zygomycosis among immunocompromised persons. Allergy types I and III. Respiratory problems, peprika splitters' lung.

Source: Soil, food; building materials, such as drywall, paper, and wood. Isolated from carpet dust samples.  Harmful Effects to Humans: No mycotoxins are known. Only one common species is able to degrade Arsenic compounds from the surfaces and release free Arsenic in the air which may be poisonous to the exposed person if inhaled. Skin nail and pulmonary infections are reported from immunocompromised persons.

Source: Soil and many kinds of trees and plants.  Harmful Effects to Humans: Not studied.

Source: Soil, decaying plant substrates, decomposing cellulose (hay, straw), leaf litter, and seeds; water-damaged sheetrock, paper, ceiling tiles, wallpaper, and insulation backing etc. Known to produce toxins in the presence of acute moisture and cellulose rich substrates inside the buildings. Harmful Effects to Humans: One species; S. chartarum var. atra is known as toxigenic among animals eating contaminated straw. It does not grow at human body temperature therefore not clearly associated with human infection. Therefore, our knowledge of human pathogenicity is still restricted to research level for this fungus. A few cases of Stachybotrys mycotoxicosis have been reported as human toxicosis resulting into skin infections, cough, rhinitis, nosebleeds, itching or burning sensation in mouth, throat, nasal passages and eyes, cold and flu symptoms, headache, general malaise, fever.

Source: Soil, wood, decaying vegetation. Some species found on leaves are plant pathogens. Harmful Effects to Humans: Hay fever, asthma.

Source: Leaf bases and stems just above the soil on many kinds of plants and trees. Harmful Effects to Humans: Not studied.

Source: Soil, dead herbaceous stems, wood, grasses, sugar beet root, groundnuts and oats. Harmful Effects to Humans: Hay fever, asthma.

Source: Soil, wood, plant parts, more common on pine needles. Harmful Effects to Humans: Toxicity is not well known. Rarely causing Keratitis to Human.

Source: Soil, dung, paint, grasses, fibers, wood, decaying plant material, paper, textiles, and water-damaged building materials, such as gypsum board. Harmful Effects to Humans: Hay fever, asthma.