Long-Term Performance of Passive Volatile Organic Compounds (VOCs) Samplers for Indoor Air

Area of Science:

• Environmental Chemistry
• Air Quality Monitoring
• Analytical Chemistry

Background:

• Reliability of passive samplers for indoor volatile organic compounds (VOCs) measurement is crucial.
• Sampler performance depends on constant uptake rates under varying environmental conditions and exposure durations.
• Vapor intrusion (VI) assessments require accurate long-term air monitoring data.

Purpose of the Study:

• To evaluate the performance of passive samplers for measuring VOCs over extended exposure durations (1 week to 1 year).
• To assess the reliability of different passive sampler types, including Radiello®, SKC 575, and Waterloo Membrane Sampler™ (WMS™).
• To determine the suitability of passive samplers for long-term indoor air quality monitoring and vapor intrusion studies.

Main Methods:

• Phase 1: Evaluated charcoal-based, solvent-extracted passive samplers (Radiello® 130, white diffusive bodies) for 1 week to 1 year in a test house with known VI.
• Phase 2: Tested Radiello® 130 (yellow diffusive bodies), SKC 575 (with secondary diffusive cover), and WMS™ for 6 months and 1 year.
• Measured VOC concentrations and calculated %Bias against acceptance criteria (±30%).

Main Results:

• Chloroform %Bias exceeded ±30% after 4 weeks.
• Benzene, hexane, and trichloroethylene (TCE) were within ±30% bias for up to 3 months.
• Toluene and tetrachloroethylene (PCE) showed uniform uptake over 1 year.
• SKC 575 and Radiello® 130 (yellow) were acceptable for 6 months; WMS™ favored petroleum hydrocarbons.
• All tested samplers showed acceptable performance for specific compounds and conditions after 1 year.

Conclusions:

• Passive samplers can provide acceptable indoor air quality data for VOCs over exposure periods exceeding 30 days, up to one year for certain compounds.
• Sampler choice and compound volatility influence long-term monitoring reliability.
• Results support the use of passive samplers for long-term vapor intrusion assessments under defined conditions.