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How the Contamination Index Supports Better Indoor Air Quality Decisions


Indoor Air Quality
Indoor Air Quality

At a high-level, how is the Contamination Index Used?

The Contamination Index is a crucial component of survey analyses. It serves as a powerful tool for understanding and evaluating the presence of air-contaminating products and materials within a given space.

When conducting a survey analysis, it measures the levels of volatile organic compounds (VOCs) present in the air. Just a reminder: VOCs are gases emitted from various sources, such as building materials, furniture, cleaning products, and other common household items. These compounds can have adverse effects on indoor air quality and human health.

By utilizing insights provided by the Contamination Index, individuals, building owners, and air quality professionals can make informed decisions to improve the air quality in indoor spaces. It is a valuable resource for implementing effective mitigation strategies, enhancing occupant well-being, and creating healthier environments.

What role does the Contamination Index play in reporting Indoor Air Quality decisions?

The Contamination Index section of survey analysis reports provides valuable information about the specific types of contaminants found within tested spaces. It categorizes these contaminants and illustrates their approximate contribution to the total VOC level.

This breakdown helps to identify the predominant sources of air pollution in the environment under investigation. Each contamination index is comprised of three main source groups, building-related, lifestyle, and mixed building and lifestyle:

Building-Related Sources relate to construction projects.

Building-related sources of VOCs are often associated with the construction or renovation of a building. These sources are typically linked to the materials and products used in the building’s structure. After construction or renovation, the levels of VOCs from these sources tend to decrease significantly within a month. It is beneficial to flush the area with fresh air to expedite the dissipation of these VOCs, allowing for improved air quality.

The building-Related Sources category encompasses various sources commonly found in buildings, including coatings, PVC Cement, and freons.

  • Coatings: interior and exterior paints (including low or no VOC paints), varnishes, lacquers, some sealants, and other products that can be classified as a coating over a surface. There is some overlap between chemical compounds associated with coatings and those found in the fuel oil, diesel fuel, and kerosene category.

  • PVC Cement: used to join pieces of PVC pipe together, usually for plumbing.

  • HFCs and CFCs (or Freons): most often used as refrigerants for air conditioners and refrigerator/freezers and propellants for blown-in insulation, cushions, aerosol cans, etc.

Lifestyle Sources relate to indoor spaces.

Lifestyle sources of VOCs in indoor spaces are associated with the activities and belongings of the occupants. These sources include products and materials brought into the space, such as cleaning supplies, personal care products, and hobbies involving chemicals. Unlike building-related sources, lifestyle sources are relatively easier to identify and address. By identifying the specific products or activities contributing to VOC emissions, appropriate remediation measures can be implemented, such as choosing low-VOC alternatives or improving ventilation to reduce exposure and improve indoor air quality.

Lifestyle sources encompass a range of everyday items and activities, including personal care products, alcohol products, odorants and fragrances, dry cleaning solvents, and Medicinals. When testing commercial spaces, these categories are realigned and included in other source types.

  • Personal care products: soap, deodorant, lotions, perfumes, hair coloring supplies, nail care supplies, oral hygiene products, and many other personal care items.

  • Alcohol products: household cleaning products, antiseptic wipes, hand sanitizers, some solvents, reed diffusers, consumable alcohol, and some pharmaceuticals.

  • Odorants and fragrances: VOCs in this category can be found in scented candles, air fresheners, scented cleaning products, and personal care products.

  • Dry-Cleaning solvents: typical dry-cleaning methods employ the use of carcinogenic chemicals. This can include some upholstery and carpet cleaning products and services.

  • Medicinals: ointments and creams and topical first aid/pain relievers.

Mixed Building and Lifestyle Sources relate to both categories together.

Mixed building and lifestyle sources of VOCs can combine both categories. In some cases, further investigation may require determining the primary category to which the sources belong. For instance, there may be contributions from building-related and lifestyle sources in spaces that have undergone recent renovation or construction. These sources could include materials used in the construction or renovation process and products brought in by occupants. Identifying the specific sources and their respective categories is crucial for implementing appropriate mitigation strategies to improve indoor air quality.

Mixed building and lifestyle sources encompass a combination of building-related materials and products associated with everyday activities. This category includes toluene-based building materials, such as certain paints or adhesives, which can release VOCs during application and the curing processes. Substances like gasoline, fuel oil, diesel fuel, and kerosene, often stored in or used near buildings, can also contaminate the air.

In addition, lifestyle sources within this mixed category include items like mothballs and moth crystals, commonly used for pest control in clothing storage. These products can emit VOCs that can impact indoor air quality. Light hydrocarbons, which include compounds like lighter fluid or certain cleaning solvents and methylene chloride, found in paint strippers and certain industrial products, are also part of this mixed source category.

  • Toluene-based building materials: adhesives and glues used in construction and maintenance, arts and crafts; adhesive removers; contact cement; coatings (paint, polyurethane, lacquer, thinners); automotive products, including parts cleaners. Additional sources include gasoline and other fuels.

  • Gasoline VOCS: typically a result of off-gassing from gas containers and gas-powered equipment such as lawnmowers, snow blowers, and minibikes stored in attached garages or basements. This category does not include exhaust emissions. Additionally, gasoline VOCs can linger on clothing after refueling at a gas station. The gasoline category comprises chemical compounds also included in the light solvent category.

  • Fuel oil, diesel fuel, and kerosene are often found in garages and basements. These fuels are less volatile; they can linger long and produce a strong, unpleasant odor. This category does not include exhaust emissions. There is some overlap between chemical compounds associated with fuel oil, diesel fuel, and kerosene and those found in coatings.

  • Mothballs: naphthalene-based mothballs. It may be present with p-dichlorobenzene-based moth crystals.

  • Moth crystals: p-dichlorobenzene-based moth crystals. It may be present with naphthalene-based mothballs.

  • Light hydrocarbons: building materials; aerosol cans; fuel for cooking/camping lighters; refrigerants; natural gas; propellants; and blowing agents. Contains chemical compounds such as propane, butane, and isobutane.

  • Light solvents: Stoddard solvents; mineral spirits; some coatings like paints, varnishes, and enamels; wax remover; adhesives; automotive products; and light oils.

  • Methylene chloride: is found in automotive products; degreasing solvents; paint strippers; adhesive removers; aerosol propellants, and insecticides.

What are the key takeaways?

  • The Contamination Index severity classifications begin at normal and progress through moderate, elevated, high, and severe. These severity classifications are determined using statistical data from thousands of samples and health information specific to each contamination index category. They are not related to safety.

  • Each Contamination Index category has its severity scale values; no two categories have the same scale. You will notice that categories such as PVC cement and methylene chloride rise to higher severity ratings at a lower concentration than categories such as odorants, fragrances, or coatings. This is based on what is seen in a typical indoor space.

  • It is possible for a category listed in one source group (Building, Lifestyle, Mixed) to belong to another source group. For example, the coatings category is in the building source group because the largest contribution is typically wall paint. However, paint cans stored in the basement or garage could be considered part of the lifestyle sources group. Always consider all possible sources for a particular contamination index category.

  • Since there are many sources of VOCs, spaces can often become re-contaminated (experience excess VOCs) after the initial sources have been removed. Remodeling improvements and new products regularly affect the space. Occupants should take note of this fact and view indoor air quality as a continuous improvement process.

  • The concentrations reported for each Contamination Index category are approximate and may not incorporate/include all VOCs in your air sample.

In conclusion…

The Contamination Index is an essential tool that helps identify, evaluate, and address air pollutants. It empowers us to understand the composition of VOCs, compare air quality levels, and take appropriate actions to ensure cleaner and safer indoor environments. In addition to identifying and quantifying contaminants, the Contamination Index section suggests where these air-contaminating products and materials might be found. This feature assists in locating potential sources of pollution and enables targeted efforts to reduce or eliminate them.

We are readily available for questions regarding the Contamination Index or other Volatile Organic Compound Testing inquiries. Your satisfaction and understanding of our services are paramount, and we are committed to ensuring a positive and informative experience for you. Thank you for considering our expertise, and we look forward to the opportunity to serve you.


Full Credit is given to:

Lucinda (Cindy) Kyser. Cindy is a Project Manager at Enthalpy Analytical in Mount Pleasant, MI. Cindy excels in bringing indoor air quality projects to fruition, closely collaborating with clients, and navigating volatile organic compounds’ complexities. Her dedication to cultivating relationships and gaining knowledge to fulfill clients’ indoor quality testing needs is evident in her work. Thriving under pressure and seamlessly adapting to various roles based on company demands further amplifies her value to the team. Enthalpy Analytical relies on her expertise to deliver exceptional indoor air quality solutions for our clients.

Printed on August 1, 2023



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