Tag Archives: residential homes

Indoor Air Quality (IAQ) Testing Services (including chemicals / carcinogens like Formaldehyde) Available – Fast Onsite Results!

Formaldehyde NFPA Diamond from MSDS (Material Safety Data Sheet)

Formaldehyde NFPA Diamond from MSDS (Material Safety Data Sheet)

ScanTech Technical Consulting performs indoor air quality tests including particulate matter in the air (residential and commercial) in the 0.5 – 2.5 micron and 2.5 micron + range  (PM 2.5 and PM10) in order to evaluate how clean your air is with respect to dust and other fine particles. We also offer formaldehyde and VOC levels testing due to chemicals used in the manufacture of pressed wood flooring, lumber, laminates, glues and other adhesives in your home and factory/office.

More information on formaldehyde can be found here:


We can also test for VOCs, (Volatile Organic Compounds) CO2 (Carbon Dioxide) levels and O2 oxygen levels in your home to check ventilation quality. Datalogging over time available to show trends and measure the effects of HEPA filtration and electrostatic air ionization units.

Our background in organic and environmental chemistry, epidemiology, advanced microbiology, medical geology  and human physiology makes us uniquely qualified to answer your concerns regarding the invisible environment you breathe every day.

July 2016 ruling by the EPA on the emissions of formaldehyde of wood products produced or imported into the United States:


The following tables and information are from:

Health Effects Notebook for Hazardous Air Pollutants

To convert concentrations in air (at 25°C) from ppm to mg/m3: mg/m3 = (ppm) × (molecular weight of the compound)/(24.45) For formaldehyde which is CH20: 1 ppm = 1.23 mg/m3.

Explanation of Formaldehyde Levels

Formaldehyde Regulatory and Health Levels Comparison

Formaldehyde Regulatory & Health Levels Comparison

AIHA ERPG–American Industrial Hygiene Association’s emergency response planning guidelines. ERPG 1 is the maximum airborne concentration below which it is believed nearly all individuals could be exposed up to one hour without experiencing other than mild transient adverse health effects or perceiving a clearly defined objectionable odor; ERPG 2 is the maximum airborne concentration below which it is believed nearly all individuals could be exposed up to one hour without experiencing or developing irreversible or other serious health effects that could impair their abilities to take protective action.

ACGIH STEL–American Conference of Governmental and Industrial Hygienists’ short-term exposure limit expressed as a time-weighted average exposure; the concentration of a substance which should not be exceeded at any time during a workday.

LC50 (Lethal Concentration50)–A calculated concentration of a chemical in air to which exposure for a specific length of time is expected to cause death in 50% of a defined experimental animal population.

NIOSH IDLH–National Institute of Occupational Safety and Health’s immediately dangerous to life or health limit; NIOSH recommended exposure limit to ensure that a worker can escape from an exposure condition that is likely to cause death or immediate or delayed permanent adverse health effects or prevent escape from the environment.

NIOSH REL–NIOSH’s recommended exposure limit; NIOSH recommended exposure limit for an 8- or 10-h time-weighted average exposure and/or ceiling.

OSHA PEL–Occupational Safety and Health Administration’s permissible exposure limit expressed as a time-weighted average; the concentration of a substance to which most workers can be exposed without adverse effect averaged over a normal 8-h workday or a 40-h workweek.


Entry Routes and Factors Affecting Indoor Radon Levels in Homes

Many people wonder how radon gas levels could be present in Dallas / Fort Worth Metroplex DFW area – how does it get inside your home and affect your health and safety?

The fact is that all parts of the Earth, regardless of geography, have some level of background radiation due to nuclear disintegrations of naturally occurring radionuclides (radioactive isotopes) including uranium in the soil, water and air. On average, rocks contain only about 1-3 ppm of uranium, though some species have as much as 100 ppm. These are typically metamorphic minerals such as granite, black shale, schist, gneiss, phosphorites, some sedimentary rock (including limestone in some cases) with a high phosphate content and metamorphic rocks derived from these rocks.

On average worldwide, the radioactive concentration of U-238, Thorium-232 and Radium-226 are ~0.65 pCi (picoCuries) per gram though this can vary significantly in very localized areas.

Radon geology home construction

Radon Intrusion Paths into Home

The major source of indoor radon is soil gas transported by pressure-induced convective flows (as shown in the illustrations) with potential entry points marked. Radon transport is enhanced when the base of the building is under significant negative pressure. Homes built on soils with higher radon release (based on soil type, porosity, pore volume, water content, etc.) and convection based transport are typically more sensitive to atmospheric factors such as temperature, wind and barometric pressure. Radon movement through soil can also occur through diffusion or both diffusion and convection.

Homes built on soils with a higher clay content (as opposed to those with sandy / gravelly soils) tend to have lower radon gas levels, but there may be trade-offs with higher moisture levels which can give rise to issues with mold, dust mites and general structural deterioration.

What are the major entry routes into your home?

1) Cracks in concrete slabs

2) Spaces behind brick veneer walls that rest on uncapped hollow-block foundations.

3) Pores and cracks in concrete blocks.

4) Floor wall joints.

5) Exposed soil as a sump.

6) Drain tile, if drained to an open sump.

7) Mortar joints.

8) Loose fitting pipe penetrations.

9) Building materials including some rocks and other decorative stones such as marble and granite.

10) Drinking / tap water.

11) Open tops of block walls.


Atmospheric Factors with Radon Levels in Homes

Atmospheric Factors with Radon Levels in Homes (Animated Graphic)

What factors affect indoor radon overall?

1) Low ventilation rates.

2) The nature of soil permeability. (by diffusion / convection mechanisms)

3) Construction materials used. Can be a significant factor in natural stone where Radium-226 concentrations are elevated. (exceed 1 pCi/gm or 1 picoCurie per gram) Emanation depends on radium density and material porosity.

4) Home water supply.

5) Meteorology (such as temperature, pressure and humidity) and the local geology of the environment.

6) Soil radon production rates based on radioactive material composition (most in the U.S. have base radon concentrations between 200 – 2000 pCi/L)

7) Cracks and fissures in the underlying geology

8) Building substructure (slab on grade, pier and beam, basement, etc.)