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Indoor Environmental Quality Testing and Advisory Services

Leverage UL’s vast experience in indoor environmental risk management, indoor environmental quality and tenant retention for commercial properties.

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UL’s Indoor Environmental Quality Program

Tenant retention

Development of a corporate indoor environmental quality (IEQ) policy results in an important tenant retention tool. Demonstrating safe indoor environmental quality will encourage your clients to continue to do business with you.

Risk management

UL’s proactive and reactive IEQ programs demonstrate an impressive rolling due diligence process. Customers who manage what they measure have far lower exposure to liability than those who only address issues when they arise. Should any tenant or third party question your commitment to a safe and healthy workplace, you will have a formidable defense.

Make buildings more valuable

UL’s IEQ programs document improvements made over time. This results in a smoother due diligence process at sale. The cost of addressing IEQ is more than recovered at sale time when the documents demonstrate a high and improving standard of IEQ over the seller’s hold time.

UL’s IEQ services

Proactive and reactive indoor environmental quality inspections 

UL’s indoor environmental quality proactive monitoring program consists of an ongoing detailed investigation of the design and operating practices of a building’s air handling and distribution system. Using comprehensive air sampling data collected from repeat inspections at prearranged intervals, we analyze and evaluate changes in the indoor environmental quality over time.

The key to a successful indoor environmental quality proactive program is that one can quantify the results of implementing changes. Conversely, if we notice adverse trends in environmental quality over time, our reactive program can guide our customers to make modifications to correct the situation before building occupants complain.

Compliance and standards 

ASHRAE 188 compliance

According to the Centers for Disease Control and Prevention (CDC), in 2018 there were roughly 10,000 cases of Legionnaires’ disease reported in the United States, however the disease is likely underdiagnosed1. The majority of incidents occur in commercial buildings water systems, most often found in cooling towers. 

ASHRAE standard 188 specifically covers risk management for building water systems as it relates to Legionnaires’ disease. As stated in the Standard of Care, building owners who document compliance with this standard will significantly reduce their liability compared with those who do not. 

ASHRAE 188-2015

According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the ANSI/ASHRAE standard 188-2015, Legionellosis: Risk Management for Building Water Systems, “is intended for use by owners and managers of human-occupied buildings and those involved in the design, construction, installation, commissioning, operation, maintenance and service of centralized building water systems and components2.” 

UL provides both ASHRAE 188 and ASHRAE 188-2015 compliance testing services.

Mold monitoring programs for commercial building owners

Environmental concerns have come to play a major role in commercial real estate development and management. Among IEQ issues, concern about toxic mold has risen to present such a liability and perception concern that forward-thinking real estate property managers routinely have their buildings inspected as part of a Proactive IEQ Monitoring Program. 

California’s Toxic Mold Prevention Act multiplies building owners’ concerns about this issue, since it formally establishes mold as a substandard condition that should be disclosed during a real estate transaction. See below for some of the monitoring services we offer.

Floods (Clean, gray and black water)

Floodwaters do colossal damage to property. Wood swells and rots, wallboard can disintegrate, and most paper items are destroyed. The mud, soil, insects, small animals and refuse carried in by the water penetrate everything.

Many long-term problems manifest themselves weeks, months or years after the floods have receded. At the top of the list of future problems are those due to the ubiquitous molds. UL offers flood management support and recommendations should your property experience damage. We provide third party assurance that the flood remediation has been successful, which allows you to confidently prove that it is safe to reoccupy the area. 

Construction monitoring services

To protect new construction from mold, moisture or IEQ problems, and potential liability issues, UL offers a powerful mold, moisture and quality assurance program with 24/7 real-time monitoring stations.

Our remote monitoring stations help you verify construction activities do not negatively impact the health and productivity of tenants and employees working near a construction site. Monitoring stations will help you address issues before they lead to work shutdown. Give building occupants peace of mind that health and safety is a priority.

Stations monitor for pollutants, nuisance odors and occupant perceptions of health risk. Receive real-time alerts if you need to address pollutant levels.

Asbestos and lead surveys and operations and maintenance (O&M) programs

There is no safe level of asbestos exposure, and products containing asbestos have not been completely banned from import or installation into current buildings. That is why many federal, state and local regulatory agencies throughout the nation are requiring owners and operators to conduct surveys for asbestos-containing materials prior to major retrofits or demolition. 

We are finding that agencies are enforcing this rule more strictly and failure to meet these requirements often results in fines and other penalties. 

Regulations for asbestos testing vary by location. To find out if UL is licensed to operate in your state, please visit to get started.

Additional indoor environmental quality testing services

The following is a listing of additional field tests and samples that UL often performs during indoor environmental quality inspections and are available to our customers on an as-needed basis. 

  • Airborne particulates
  • Airborne mold constituents
  • Surface mold
  • Lead and copper in drinking water
  • WaterScreen® (comprehensive drinking water screening)
  • Legionella
  • Air handling unit(s) inspection
  • Volatile Organic Compounds – full spectrum identification
  • Formaldehyde
  • Datalogging – carbon dioxide, carbon monoxide, temperature, relative humidity
  • Miscellaneous gases (nitrogen dioxide, sulfur dioxide and hydrogen sulfide)
  • Electromagnetic field (EMF) screening

Note: these are just some of the more common tests and samples we conduct in commercial buildings. We can meet client sampling needs for many situations based on your unique field characteristics.

Industrial hygiene services

UL offers a wide range of industrial hygiene monitoring services and consulting for building owners to document occupational exposures.

Due diligence inspections and property condition assessments

Building purchasers frequently retain UL to review buildings during the due diligence period. Some or all of the above services can be included in these inspections.


Indoor Environmental Quality

Topics include:

  • IEQ basics
  • Mold in commercial buildings
  • Asbestos issues
  • Lead hazards
  • HVAC operation and maintenance
  • Temperature and psychometrics
  • Air filtration

Health and safety

Topics include:

  • Site assessments and audits
  • OSHA compliance
  • Hazard communication and SDS
  • Emergency response
  • Ergonomics in the workplace
  • Lock out/tag out
  • Electrical safety
  • Personal Protective Equipment (PPE)
  • Welding, cutting, brazing/arc flash
  • Confined space entry

WaterScreen® drinking water testing 

WaterScreen is UL’s proprietary water quality test designed to provide a comprehensive and economical analysis of a building’s drinking water, which confirms its suitability as a healthy potable source. Our in-house laboratory analyzes all samples using only validated science-backed methodologies, such as:

  • Microbial analysis
  • Ion chromatography
  • Inductive coupled plasma mass spectroscopy
  • Titration methods

Our WaterScreen analysis compares your samples with the relevant EPA Maximum Contaminant Level for drinking water.

WaterScreen benefits 

WaterScreen offers several benefits to our customers including:

  • Better risk management and reduced liability
  • Healthier and safer work environments
  • Enhanced employee/tenant relations
  • Third-party certification of building status
  • Proof of due diligence for liability protection
  • Marketing advantages for tenant retention

We present our analysis results in a clear format along with a helpful interpretation of the findings.

WaterScreen services serve as a valuable addition to the UL proactive indoor air quality program with no extra labor charges since we are already in the building, or along with your compliance program for ASHRAE standard 188, Legionellosis: Risk Management for Building Water Systems. Alternatively, UL offers WaterScreen as a standalone drinking water monitoring service.

Legionella testing and risk assessment

We designed out sampling protocol to ensure accuracy, avoid ambiguity, protect customer confidentiality and to aid in diagnosis of contaminated water systems.


  1. CDC: Legionella: About the Disease 

  2. ANSI/ASHRAE Standard 188-2018, Legionellosis: Risk Management for Building Water Systems

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