Analyzing Volatile Organic Compounds and Semivolatiles

Volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) are chemicals that can evaporate into the air we breathe. Some VOCs and SVOCs can have short- and long-term health effects, so testing air, water, soil and consumer products for these compounds is important to protect human health.

This detailed article provides an in-depth overview of VOC and semivolatile testing methods, applications, reasons for analyzing these compounds, and health impacts.

What are VOCs and Semi-Volatiles?

Volatile Organic Compounds

VOCs are organic chemicals that easily evaporate at normal room temperature. This means they readily get into the air and can be inhaled. Common sources of VOCs include paints, adhesives, cushions, carpeting, cleaning products, building materials, office equipment, dry-cleaned clothing, graphics, glues, solvents, fuels, and many other products used every day.

Some examples of hazardous VOCs include:

Benzene – Found in tobacco smoke, gasoline, glues, cleaners, and plastics. Linked to cancer and organ damage.
Toluene – Used in paint thinner, fingernail polish, lacquers, and adhesives. Causes headaches and dizziness.
Xylenes – Found in gasoline, paints, and solvents. Irritates eyes, nose, throat, and skin.
Formaldehyde – Used in pressed-wood products and insulation. Probable human carcinogen.
Chloroform – Found in chlorinated water. Suspected carcinogen.
Ethylene glycol – Used in antifreeze, brake fluid, paints. Toxic if ingested.

Other common VOCs include acetone, tetrachloroethylene, and methyl chloride. There are thousands of VOCs derived from petroleum, plants, cleaning agents, refrigerants, and more.

Semivolatile Organic Compounds

SVOCs are organic compounds that do not readily evaporate at room temperature due to having lower vapor pressures and higher boiling points than VOCs.

Some examples of hazardous SVOCs include:

Phthalates – Used to make plastics more flexible, found in toys, food packaging, cosmetics. Linked to endocrine disruption.
Pyrethroids – Common pesticides toxic to the nervous system.
Polycyclic Aromatic Hydrocarbons (PAHs) – Released from burning oil, gas, coal and waste. Carcinogenic.
Polychlorinated Biphenyls (PCBs) – Formerly used as coolant and insulating fluids. Probable human carcinogen banned since 1979.
Organochlorine Pesticides – Includes DDT, chlordane, dieldrin. Many banned due to toxicity and persistence.

Testing air, surfaces, dust, and materials for SVOCs can identify sources of exposure, like pesticide application or PCB-containing old fluorescent light ballasts. SVOCs are found in hydraulic fluids, paints, solvents, lubricants, adhesives, pesticides, flame retardants, cleaners, and other products.

Why Test for VOCs and Semivolatiles?

Monitor Indoor Air Quality

Testing indoor air, dust, and surfaces for VOCs and SVOCs can identify sources of exposure and contamination. This allows corrective actions to be taken to improve indoor air quality by eliminating VOC/SVOC sources, increasing ventilation, or utilizing air cleaning technologies. VOCs also influence indoor chemistry and can lead to the formation of harmful secondary pollutants like formaldehyde.

Assess Health Risks

Many VOCs and SVOCs are classified as toxic or hazardous substances capable of causing short-term and long-term health effects. Testing helps evaluate potential risks and facilitates risk reduction by enabling the identification and elimination of VOC/SVOC sources. This is especially pertinent for sensitive populations like children and the elderly.

Ensure Regulatory Compliance

There are regulations limiting the VOC and SVOC content of consumer products and emissions from industries. Testing is conducted to demonstrate compliance with rules like EPA’s National Emission Standards for Hazardous Air Pollutants (NESHAP). VOC regulations also apply to architectural coatings and motor vehicle fuels.

Evaluate Abatement

Testing is used to monitor the effectiveness of VOC removal and remediation at contaminated sites such as Superfund sites and brownfields. VOC/SVOC sampling helps determine if cleanup goals have been achieved. Technologies like vapor intrusion mitigation can also be evaluated.

Analyze Consumer Products

Many consumer products contain and emit VOCs and SVOCs. Testing helps identify potential exposures and health risks. For example, VOC testing of building materials like carpets and furniture allows selection of low emitting products. Toy and children’s product testing can identify banned phthalates.

Workplace Safety

VOC/SVOC testing facilitates occupational exposure monitoring to protect workers in industries that utilize solvents, pesticides, adhesives, fuels, and other VOC/SVOC-containing products. It helps evaluate hazards and the effectiveness of exhaust ventilation.

Site Assessments

Testing soil, groundwater, and air helps locate VOC/SVOC contamination during environmental site assessments and identify responsible parties for cleanup. VOCs like benzene and toluene from buried petroleum tanks are common concerns.

Fire Investigation

Many ignitable liquids like gasoline, lighter fluid, and paint thinners contain VOCs. VOC testing can detect accelerants and facilitate arson investigations after fires.

Many VOCs and SVOCs can impact human health

Acute Effects

Headaches, dizziness, nausea
Eye, nose and throat irritation
Skin irritation
Liver, kidney, and CNS damage

Chronic Effects

Cancer (leukemia, lymphoma, liver, breast, kidney)
Neurotoxicity (cognitive and motor deficits)
Endocrine disruption (reproductive and developmental effects)
Organ damage (lungs, liver, kidneys)

Health impacts depend on the VOC/SVOC, level and duration of exposure, and individual susceptibility. Sensitive populations like children, the elderly, pregnant women, and those with existing medical conditions are at increased risk.

VOC and SVOC Testing Methodology

Various well-established analytical methods are used to test environmental, air, product, liquid and solid samples for VOCs and SVOCs:

VOC Testing Methodology

EPA Method TO-15 – Whole air samples are collected in specially prepared and evacuated stainless steel canisters. The canisters are sent to a lab where they are analyzed via gas chromatography/mass spectrometry. Hundreds of VOCs can be identified and quantified at very low concentrations. TO-15 is the EPA standard method for assessing VOCs in indoor air quality investigations.

EPA Method TO-17 – Air is sampled by pulling it through sorbent tubes containing materials that capture VOCs. The tubes are sent to a lab where VOCs are desorbed using heat then analyzed via gas chromatography with mass spectrometry detection. TO-17 has lower detection limits than TO-15 for many compounds.

Direct Interface Gas Chromatography – This technique allows real-time monitoring of VOCs in air. An analytical system connected directly to a sampling point provides VOC measurements within seconds rather than waiting hours or days for lab results. While less sensitive than TO-15 or TO-17, it provides immediate quantitation useful for locating VOC sources or monitoring hazardous atmospheres.

Photoionization Detectors (PIDs) – PIDs use an ultraviolet lamp to ionize VOCs which generates a current proportional to their concentration. Battery-operated handheld PIDs provide real-time, on-the-spot VOC measurements. They are relatively inexpensive, simple to use, and intrinsically safe for monitoring flammable VOCs. However, they do not differentiate between types of VOCs and have detection limits in the parts per million (ppm) range.

SVOC Testing Methodology

EPA Method TO-13 – Air is pulled through sorbent cartridges or tubes to trap SVOCs. The sorbents are sent to a lab and analyzed using either gas chromatography/mass spectrometry or liquid chromatography/mass spectrometry with additional sample preparation. This sensitive technique can detect SVOCs like PCBs and pesticides at parts per trillion (ppt) levels.

GC/MS Analysis – Liquid, solid, or wipe samples collected in the field are sent to a lab where SVOCs are extracted using solvents, concentrated, and injected into a gas chromatograph interfaced to a mass spectrometer. The GC/MS identifies and quantifies specific SVOCs. Ultrasonic or Soxhlet extraction methods are commonly used.

GC/ECD Analysis – A gas chromatograph equipped with an electron capture detector (ECD) allows detection of halogenated SVOCs like PCBs, dioxins, and some pesticides at extremely low concentrations down to parts per quadrillion (ppq). Sample preparation is critical to minimize interferences.

LC/MS Analysis – Liquid chromatography separates non-volatile SVOCs then identification is performed by mass spectrometry. LC/MS methods can analyze higher molecular weight SVOCs not amenable to GC/MS.

Applications of VOC and SVOC Testing

VOC and SVOC testing via TO-15, TO-17, GC/MS, LC/MS, and other methods are applied across many fields:

Indoor Air Quality Assessments

Testing indoor air, materials, and dust helps locate VOC/SVOC sources and identify contaminants impacting air quality in homes, offices, schools, and other buildings. Mitigation strategies can then be implemented.

Industrial Hygiene

VOC/SVOC testing is commonly used for occupational exposure monitoring and health hazard evaluation at manufacturing facilities that use paints, adhesives, degreasers, fuels, pesticides, and other chemical products containing volatile and semivolatile organics.

Environmental Site Assessments

Soil, groundwater, ambient air, and soil gas are tested during Phase I and Phase II site assessments to identify VOC/SVOC contamination and sources, often due to petroleum hydrocarbon spills and releases. This helps determine cleanup responsibilities.

Building Materials Testing

The emissions and content of VOCs/SVOCs in building products and furnishings are evaluated via chamber testing and chemical analysis. Low VOC-emitting materials can then be selected to enhance indoor environmental quality.

Consumer Products Testing

Chemical analysis and emissions testing of consumer goods is conducted to evaluate potential VOC/SVOC exposures from products like cleaners, air fresheners, paints, glues, toys, electronics, and clothing.

Contamination Control

VOCs/SVOCs are common contaminants in cleanrooms during electronics and pharmaceutical production. Stringent monitoring and control are required to prevent product contamination. Testing also facilitates healthcare sterility assurance.

Fire Investigation

Ignitable liquids leave VOC residue after fires. Testing fire debris and samples with GC/MS and other methods can provide proof of incendiary accelerant usage suggesting potential arson.

Remediation System Monitoring

Testing air and soil during and after VOC removal by vapor mitigation, dual phase extraction, or bioventing provides data to evaluate remediation system performance and determine if cleanup goals have been achieved.

And Finally

VOCs and SVOCs are prevalent yet potentially hazardous compounds in our everyday environments and products. Analytical testing facilitates the detection of these chemicals at trace levels and enables proactive identification and reduction of contamination sources. VOC/SVOC analysis provides actionable environmental intelligence to improve public health and safety by limiting human exposures through better-informed control strategies. The science behind VOC/SVOC testing continues advancing with higher precision methodology and greater sensitivity at parts per quadrillion or lower.

VOC testing provides peace of mind. Knowing that you or your business has taken proactive steps to ensure a healthy environment can relieve stress and contribute to overall well-being. In summary, VOC testing is not just a regulatory requirement or a health precaution; it is an essential practice for maintaining a safe and healthy environment in both residential and commercial buildings.

VOCs, SVOCs and Odors

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