Odor Surveys and Assessments

If you ever had an odor issue within your facility you can appreciate the difficultly in identifying the odors, the sources and responding to questions from employees. The professionals at 1Source have developed a specific protocol that has been successful in identifying odors and odor sources that are:

• external to a building, i.e not related to a buildings systems, or processes and occupants within a building
• internal to a building, i.e. related to a buildings systems, or processes and occupants within a building.

1Source professionals utilize their understanding of potential odor generating sources as the first step in resolution of the odor problem.

In order to assist in the resolution of odor issues, it is beneficial to gather some information to assist in determining what steps need to be taken and if sampling is needed. Questions such as the following should be answered prior to conducting any type of sampling or assessment.

• When odor is present, what are its boundaries?
• We know where the odor does not appear?
• What is the pattern associated with the odors presence?
• Are odors present above ceilings?
• What does the odor smell like? Intensity?
• Does weather affect the presence or intensity of the odor?
• Are odors present throughout an entire areas served by an AHU?
• Are odors present before employee’s come into building?
• Are HVAC systems shutdown overnight?
• Are there any janitor closets in the areas?
• Are odors present during the night?
• Are odors present over the weekends?
• Does everyone perceive the odor?

The perception of an odor within a building is a clear indication that there is a problem that must be resolved. It is important to note that while some odor causing compounds can be simply categorized as being a nuisance others are potential health hazards.

Need more information, or a proposal? Please click on Information Request, or contact Christian M. Schneider, CIH President at 888.873.9983 ext 14 or cschneider@1ssh.com.

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Summary of Odor issues

If you ever had an odor issue within your facility, you will know the difficultly in identification of a source(s) and cause(s). The following summary and recommendations have proven to be successful in the identification and mitigation of odor sources.

Chemical compounds from chemical products or microbiological activity typically cause odors. Odors can be perceived with olfactory senses even when the contaminant concentration cannot be detected by sensitive analytical instrumentation. Compounds that cause odors can oxidize and change chemically making their detection difficult and / or impossible.

The release of an intermittent odor from an indoor cause and source is generally regulated by a change in its pathway(s) and driving force(s). Driving forces determine the pathway from an odor source. Building pressure, system pressures, temporary or permanent blockages causing pressure build-up, HVAC systems, and the effects of weather conditions on a building are examples of driving forces.


Odors are from sources:

• external to a building, i.e. not related to a buildings systems, or processes and occupants within a building
• internal to a building, i.e. related to a buildings systems, or processes and occupants within a building

Outdoors

Outdoor entrainment can occur through:

• outdoor air intakes
• uncontrolled leakage due to negative building pressure and / or system pressure

Outdoor causes and sources can be extensive, but general categories include:

• Vehicle emissions
• Fugitive emissions from nearby facility(s)
• Fugitive emissions from other parts of facility
• Ground gases from soil contamination

Indoors
Indoor dispersion can occur via the HVAC system(s), and other controlled and uncontrolled airflow, which are caused by many factors.

Indoor causes and sources include:

• Building systems
  
  1. Sanitary sewage discharge and venting systems
   
  • Re-entrainment of vented gases (methane / hydrogen sulfide), this would tend to distribute odors throughout all areas served by an HVAC unit
  • Breach in vent stack / vent stack joints located within the structure (methane / hydrogen sulfide) intensity of odor would depend on system use, size of breach, draft within vent, pressure differential between vent pipe and surrounding area, back pressure caused by discharge flow volume variations and interception point flow restriction,
  • Broken seals around water closets and urinals
  • Dry or unsealed drain traps
  • Broken discharge pipe resulting in odor accumulation under the slab. Intensity of the odor would vary with building pressure in relation to under slab pressure, cracks in the concrete flooring, floor penetrations for conduits
  • Grease traps that are improperly maintained
  • Insufficient pitch of sanitary sewage lines under the floor

  2. HVAC systems

  • Condensation pan and drain
  • Wet insulation, in duct or mix box
  • Mold growth in the HVAC system and associated ductwork
  • Insufficient or excessive exhaust air
  • Entrainment of kitchen exhaust air
  • Fuel fired boilers

  3. Electrical systems

  • Overheating ballasts with melted insulation
  • New computers or other electronic equipment
  • Emergency generators

  4. Roofing

  • Breach in roof integrity which would allow water liquid flow and allow for the growth of bacteria and mold in the roofing system
  • Odors from chemicals, tar, and other products used during roof replacement

  5. Windows and walls

  • Water intrusion around windows resulting in hidden mold and bacteria growth and decomposition of materials
  • Water absorption and transfer through brick and mortar resulting in hidden mold and bacteria growth and decomposition of materials
  • Water intrusion around flashing etc resulting in hidden mold and bacteria growth and decomposition of materials

  6. Floor systems

  • Cracks and floor penetrations allowing soil gases to enter the building. Intensity of the odor would vary with building pressure in relation to under slab pressure, cracks in the concrete flooring, and floor penetrations for conduits. Subsurface conditions and or pollution can be a source.
  • Floor penetrations between floors that allows transfer of odors from one floor to another
  • Raise flooring allows for collection of debris and rodents
  • Cabling channels in floor covered with steel plated. May dead end at an odor source, or receive and hold water
     
• Occupants
  
  1. Personal hygiene product use
   
  • Level of personal care
  • Perfumes and colognes

  2. Sabotages

  • Intentional release or application of an odor or irritant causing substance

  3. Food storage

  • Food storage in closets, desk drawers, and waste cans
     
• Processes
   
  • Processing equipment
  • Manufacturing equipment
  • Maintenance procedures / chemicals
  • Housekeeping
  • Trash storage and disposal systems
  • Loading docks
     
•  Furniture systems
   
  • Off-gassing of new furniture
  • Odors from stored or used furniture

In order to assist in the resolution of odor issues, it is beneficial to gather some information first to assist in determining what types of sampling and where the sampling needs to be conducted within the facility. Questions such as the following need to be answered prior to conducting any type of sampling or assessment.

• When odor is present, what are its boundaries?
• We know where the odor does not appear?
• What is the pattern associated with the odors presence?
• Is odor present above ceilings?
• What does the odor smell like?
• Does weather affect the presence or intensity of the odor?
• Is odor present throughout an entire areas served by an AHU?
• Is odor present before employee's come into building?
• Are HVAC systems shutdown overnight?
• Are there any janitor closets in the areas?
• Is odor present during the night?

Recommendations:

• Get answers to the above noted questions
• Begin keeping a log for a few weeks. This might allow us to look back at what was occurring in the building at that time.
• When odor is present shut down systems and conduct air sampling and olfactory evaluations to identify areas of low and high intensity. This will assist in focusing in on the point source, as contaminants tend to migrate in a rolling fashion from a source.
• Evaluate air prior to employees coming in to work.
• Conduct air sampling with various direct reading and sampling media.

Need more information, or a proposal? Please click on Information Request, or contact Chris Schneider, CIH, President at 888.873.9983, Ext 14 or cschneider@1ssh.com

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What Smells?

Whenever an unfamiliar odor is perceived within a building, it conjures up a level of concern that the air quality is poor and the air is unhealthy. Odors do not equal unhealthy air. This is rarely the case. Unfortunately, if just one employee believes it, you now have a problem. Legitimate or not, it has to be addressed. If you have ever had an odor issue within your facility, you will know how difficult it is to identify a source and a cause.

This is especially true when the odors are intermittent, or move around from area to area within the building. Please remember that finding the source of an odor and resolving the problem require a well-planned approach and time for implementation.

HINT: Do not do air sampling to identify compounds. Why? Typically, odor-causing compounds have very low odor thresholds and will not be detected by analytical equipment. In other words, in many cases your nose can detect the presence of compounds before sampling can! Some instruments may be used later in the investigation.

There are several steps to resolving odor issues. The first is to meet with employees and develop a list of trends and possible sources. With this information, an Odor Event Log is developed for employees to log in characteristics of the odor over several weeks. Input from employees is critical not only because it may be accurate, but also because the process empowers the employees to be part of the solution. Second, review the input from the employees along with the Odor Event Log to identify any possible trends related to day of week, time of day, weather conditions (wind, sun, clouds, humidity, rain, etc) processes in the building, etc. Looking for trends is important, as the release of an odor from an indoor source is generally regulated by a change in its pathway and driving forces. If you cannot identify any trends, review the information with several people including the employees who are affected. At this point you might choose to retain a consultant with significant experience in odor investigation to assist.

Third, based on the characteristics of the odor episodes, you should now begin to investigate building systems that could be contributing to the problem. For example, if the odor is sweet or aromatic you might want to look at possible entrainment from outdoors, or for moisture sources under impervious flooring (ceramic, vinyl, etc.), as trapped moisture allows for the growth of bacteria that can release organic compounds.

HINT: Remember to look under and behind walls, flooring and ceilings. You might need to do some destructive removal of materials in order to get to possible sources. Remember, it is as important to rule out sources as it is to find the actual source.

Although most of an odor investigation can be accomplished by looking and smelling, there typically will be a need for instrumentation to measure pressure differentials or to measure certain gases like methane or organic compounds to track down an exact emission point.

HINT: For more information, visit our website at www.1ssh.com and go to the Odor web page under Indoor Air Quality Management. There you will find additional information.

Please contact Harry M. Neill, CIH, Vice President, at 888.873.9983, ext 15, or hneill@1ssh.com to discuss any questions or to request a proposal.

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Located near Philadelphia, our professional staff assists clients throughout Pennsylvania, New Jersey, Delaware, Maryland, the mid-Atlantic region and across the nation. 1Source Safety and Health, Inc., 140 S. Village Ave., Suite 130, Exton, PA 19341