If you’re measuring semi-reactive gases like ethylene oxide (ETO) or formaldehyde, SUMMA canisters can quietly set you up for false negatives.
Here’s the tradeoff in plain English:
SUMMA canisters (EPA TO-15): where they shine
Advantages
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Great for broad VOC screening (dozens–hundreds of compounds in one shot)
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Simple field logistics: grab sample, ship, analyze by GC/MS
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Useful for building IAQ investigations when you don’t know what you’re chasing
Disadvantages (big ones for reactive analytes)
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Some compounds don’t remain stable in a humid, mixed air matrix inside a canister
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Wall losses / reactions / hydrolysis can reduce the analyte before it ever reaches the instrument
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Storage time matters: the longer it sits, the higher the risk you’re measuring the canister chemistry—not the air
For ETO, this is especially important: ETO can react with water to form products like ethylene glycol and PEGs, and this is catalyzed by amines (e.g., ammonia) that are commonly present in air. In a workplace context—where you need confident answers at low concentrations—this is exactly how “non-detect” can become misleading.
Reactive sorbent sampling (tubes + pump or diffusive samplers): where it wins
Advantages
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Designed to lock the molecule in place immediately (capture/derivatize at the point of sampling)
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Better for time-weighted averages (the way exposures are actually evaluated)
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Much less prone to “it disappeared in the container” problems
How we approach it
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Formaldehyde & reactive aldehydes: we use DNPH derivatization (NIOSH 2018 / EPA TO-11A), the industry-standard approach for capturing reactive carbonyls.
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ETO at ppb levels: we further developed OSHA 1010, using HBr to derivatize ETO as bromoethanol. Practically, that means we can reach ppb sensitivity with:
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~8 hours using an SKC 575 diffusive sampler, or
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~4 hours with a pump + sorbent tube setup
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VOC screening without the cost of canisters: EPA TO-17
If your goal is VOC screening + quantitative measurements (similar to TO-15/SUMMA), our EPA TO-17 approach provides:
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Broad VOC coverage with quantitative results
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Lower total cost vs. canisters
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Simpler logistics: tubes are far easier/cheaper to ship than canisters
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True breathing-zone sampling using SKC Ultra Samplers, which is often what you actually need for workplace exposure assessments
Check out our VOC product line here
hs-ETO: ppb sensitivity, lower cost, no “canister loss” false negatives
For ETO specifically, we also offer hs-ETO measurements that deliver:
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PPB sensitivity
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Lower cost than SUMMA approaches
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Better confidence for reactive ETO because we avoid the canister-stability problem that can drive false negatives
Bottom line
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TO-15 + SUMMA cansiter: for stable VOCs and unknown screening
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Reactive sorbent methods: the right tool for ETO and aldehydes when you need reliable low-level results—especially for workplace decisions
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TO-17: strong option for VOC screening + quantification, with easier shipping and better breathing-zone applicability