Odor Inspections

Odors are the most difficult problem that Environmental Consultants encounter when dealing with Indoor Air Quality.  There are several reasons, but among the most intriguing is that individuals, particularly the sexes, vary greatly in their ability to sense odor. Women generally have much greater sensitivity to odors than do men.  A frequently encountered problem is that a woman detects and is bothered by an odor that her male partner, associate or office colleague do not smell. Some physicians attribute this to the mother syndrome, i.e., a woman’s highly sensitized danger sensors inherent with her biological role in child protection and rearing.  Whatever the cause, our experience has borne out the truth of the difference in women’s and men’s odor sensitivities. Fortunately, we have instruments and chemical tests that can overcome the olfactory gender deficiency and allow us to scientifically locate the odor source.


The causes of indoor odors are many and include Volatile Organic Compounds (VOCs), external odors from outside or from adjoining habitats, home generated, human occupation.




VOC odors are off-gassed (evaporate into the air) usually from common chemicals encountered in our everyday living and are typically found in most homes, businesses and offices.


  •   Food and decaying organic materials
  •   Vinyl shower curtains, covers and flooring
  •   Combustion gasses from heating systems, fuels and oils stored in attached garages or basements
  •   Mold odors from fungus propagating in walls floors and ceiling
  •   Solvents and cleaning agents,
  •   Adhesives
  •   Paints, varnishes and stains
  •   Gasoline, fuel oil and lubricating oils
  •   Caulking, sealants and coatings
  •   Wall coverings
  •   Carpeting
  •   Wrinkle free fabrics, drapes and furnishings
  •   Perfumes, hair sprays etc.,….and
  •   Others




The air close to our building and the soil immediately abutting our homes and work building can allow contaminants from the outside to intrude on the air quality of the building air we breathe.  Examples of this include:


  •   Leaking fuel oil contamination from up-gradient underground fuel storage tanks
  •   Solvent contamination from nearby facilities that use and store solvents such as dry cleaning facilities, auto repair facilities, etc.
  •   Contaminants from the soil surrounding our building left over from other facilities that previously occupied the land (gas stations, farms, repair facilities)
  •   Pesticides used to treat the building for termites, ants, etc.
  •   Herbicides used to remove poison ivy or other vegetation close to the building.
  •   Process exhaust from nearby facilities, dry cleaners, laundries, printers, etc.
  •   Vehicle exhaust from nearby cars, trucks, buses etc.
  •   Combustion exhaust from building nearby




Odors found indoors are frequently caused by situations or materials used in our homes or faults and failures of home appliances or equipment.  Our daily lives are also exposed to the invention of new synthetic materials and adhesives used for manufactured furniture, carpeting and carpet backing, treatment chemicals for wrinkle fee fabrics etc.  Among the more common include:


  •   Tobacco smoke,
  •   Cooking odors,
  •   Body Odors, contaminated work out clothing, shoes, boots,
  •   Off-gassing from home and office equipment (printers, faxes, copiers, etc.),
  •   VOCs from solvents, ammonia, chlorine bleach products and other cleaning products,
  •   Vapors and gases from carpets, furnishings, and other building components, formaldehyde from wood glues, fabric treatments, stains and varnishes),
  •   Emissions from special use areas within the building such as laboratories, print shops, art rooms, smoking lounges, beauty salons, food preparation areas, and other various chemicals and related odors,
  •   Emissions from indoor construction or renovation activities,
  •   Faulty building motors, (elevator, exhaust, HVAC etc.)  and other building mechanical systems,
  •   Contaminated HVAC and air conditioning systems,
  •   Sewer drain odors, improper bathroom ventilation,
  •   Poorly located roof sewer vents, exhausting near fresh air supply intakes,
  •   Odors from housekeeping / cleaning materials (ammonia, chlorine, and other cleaning agents such as detergent, dust residual from carpet shampoo, and disinfectants),
  •   Odors from pesticide use inside the building,
  •   Fire damage inside the building (soot, polychlorinated biphenyls from electrical equipment, odors), and
  •   Gases from construction activities (roofing chemicals, road paving)


Although present methods and instruments for odor detection and identification are impressive, the reality is that the human olfactory senses are frequently substantially more sensitive than the present state of the science.  As an example, there exist some odors, which can be detected by humans at such low levels, that no available instrument or chemical test can approach such levels of sensitivity. For example, Methyl Mercaptan (MM) can be detected by humans at levels as low as 5 parts per billion.  Thus MM is used as an odorant in natural gas (which is odorless) to enable users to detect its presence from leaking pipes of burners. The gas company or fire departments response teams arrive on scene when a report of a natural gas leak is received (actually MM) bringing with them instruments to test for the presence of Methane gas.  Even if they wished to test for the presence of MM there presently no existing capability of detecting MM at the levels it would be present in a natural gas leak.; while just about any human would smell its presence. The point of this example is to show that there are instances where the human olfactory system is superior to instrument and scientific tests when attempting to identify an odor.  Moreover, there are many odors in nature that are similarly difficult to measure even though they can be “smelled” by the client. In such instances where Boston Environmental is unable to identify an odor or the source of an odor, through the use of portable technical equipment, other approaches can be offered and coordinated by Boston Environmental. The approach would include interviews by a member of the Boston Environmental technical staff using proven scientific techniques to narrow the number of possible offending materials or compounds and then to propose and oversee a series of steps to ascertain the most likely cause.  Corrective measures would then be proposed to eliminate the cause; the final option is to remove furniture/carpet items from the affected room or area and hope that the odor disappears.