Indoor How Does Indoor Plants Get Carbon Monoxide (2026)

By Emma Johnson · November 25, 2021

Why This Question Matters More Than Ever

Indoor how does indoor plants get carbon monoxide is a question surfacing with alarming frequency in home safety forums, Reddit threads, and Google autocomplete — revealing widespread confusion about basic plant biology and household air hazards. The truth? Indoor plants do not absorb, metabolize, or remove carbon monoxide (CO) from indoor air — not even trace amounts. This isn’t a limitation of certain species; it’s a hard physiological boundary rooted in plant biochemistry. Yet millions continue placing peace lilies beside gas stoves or trusting spider plants to ‘clean’ garage workshops — creating dangerous false confidence. With CO poisoning causing over 400 U.S. deaths annually (CDC, 2023) and residential incidents rising during colder months when windows stay sealed, clarifying this myth isn’t just academic — it’s life-saving. Let’s dismantle the misconception, explain exactly what plants *do* with gases, and equip you with evidence-based strategies that actually work.

Plants and Gases: What They Actually Exchange (and What They Can’t)

Plants perform gas exchange primarily through microscopic pores called stomata — mostly on leaf undersides. During daylight, they take in carbon dioxide (CO₂) for photosynthesis and release oxygen (O₂). At night, most switch to cellular respiration: consuming O₂ and releasing CO₂. Crucially, carbon monoxide (CO) is chemically inert to plant metabolic pathways. Unlike CO₂, which binds to the enzyme RuBisCO in chloroplasts, CO lacks the molecular structure to engage with photosynthetic or respiratory enzymes in vascular plants. As Dr. Linda Chalker-Scott, Extension Horticulturist at Washington State University, confirms: ‘Plants have zero enzymatic machinery to break down CO. It’s like asking a toaster to brew coffee — the hardware isn’t designed for that function.’

This isn’t speculation. A landmark 2019 study published in Environmental Science & Technology tested 12 common houseplants (including pothos, snake plant, and areca palm) in controlled chambers exposed to 50 ppm CO for 72 hours — a concentration well above the EPA’s 9-ppm 8-hour exposure limit. Using laser-based gas chromatography, researchers detected no statistically significant reduction in CO levels compared to control chambers without plants (p = 0.87). Meanwhile, CO₂ levels dropped as expected — proving the plants were physiologically active, yet completely unresponsive to CO.

So where did the myth originate? Largely from misinterpretation of NASA’s famous 1989 Clean Air Study. That research demonstrated certain plants *can remove volatile organic compounds (VOCs)* like benzene, formaldehyde, and trichloroethylene — but CO was never tested, nor mentioned in the report. Over decades, ‘air-purifying plants’ became a marketing umbrella term, erroneously expanded to include CO despite zero scientific basis. Today, social media influencers compound the error with videos showing CO detectors ‘going quiet’ after adding plants — a classic case of confirmation bias, ignoring detector calibration drift or ambient temperature shifts.

The Real Danger: When ‘Plant Safety’ Creates False Security

Believing plants protect against CO isn’t harmless folklore — it actively undermines proven safety protocols. Consider this real-world case from the National Fire Protection Association (NFPA) 2022 incident database: A family in Minnesota installed six ZZ plants and a fiddle-leaf fig near their gas furnace, citing ‘natural air cleaning’ advice from a home decor blog. When the heat exchanger cracked, CO built up silently overnight. Their battery-powered CO detector had expired — and because they believed the plants were ‘handling it,’ they’d disabled the alarm’s low-battery chirp. All three residents suffered acute poisoning; the youngest child required hyperbaric oxygen therapy.

This illustrates the core risk: CO is odorless, colorless, and tasteless — and plants provide zero sensory or functional warning. Unlike VOCs (which may cause headaches or eye irritation at high levels), CO binds to hemoglobin 240x more tightly than oxygen, causing tissue hypoxia before symptoms appear. Early signs — dizziness, nausea, fatigue — mimic flu or stress, delaying evacuation. By the time someone feels ‘off,’ CO saturation may already exceed 30% — a critical threshold requiring immediate medical intervention.

Worse, some ‘CO-safe’ plant recommendations inadvertently increase risk. Placing moisture-loving plants like ferns or calatheas in basements or utility rooms can elevate humidity near gas appliances, accelerating corrosion of heat exchangers and increasing CO leakage potential. Similarly, dense foliage around furnace vents restricts airflow, causing incomplete combustion — the primary source of residential CO.

What Does Work: Evidence-Based CO Mitigation Strategies

If plants don’t help, what actually reduces CO risk? A layered, engineering-first approach — validated by the U.S. Consumer Product Safety Commission (CPSC) and Underwriters Laboratories (UL). Here’s your actionable, non-negotiable protocol:

Install UL-certified CO alarms on every level of your home, especially outside sleeping areas. Choose units with digital displays showing real-time PPM levels — not just binary alerts. Replace every 5–7 years (per manufacturer specs).
Schedule annual professional inspection of all fuel-burning appliances (furnaces, water heaters, stoves, fireplaces) by a certified HVAC technician. Request combustion analysis — measuring flue gas CO levels and draft pressure.
Maintain ventilation integrity: Never block vents, flues, or exhaust ducts. Use range hoods vented outdoors when cooking with gas. Crack windows for 10 minutes daily during winter to dilute accumulated gases — even 0.5 ACH (air changes per hour) reduces CO buildup by ~40% (ASHRAE Standard 62.2).
Eliminate high-risk behaviors: Never run generators, grills, or camp stoves indoors or in attached garages. Avoid idling cars in closed garages — CO can seep into living spaces within minutes.

Curiously, while plants don’t remove CO, some *do* support overall indoor air quality in ways that indirectly reduce CO exposure risk. For example, English ivy (Hedera helix) significantly reduces airborne mold spores (NASA study), and since mold growth often coincides with poor ventilation — a key CO risk factor — maintaining healthy plants can be part of a holistic air management strategy. But this is correlation, not causation. Never substitute plant care for CO monitoring.

Plants That Do Remove Harmful Gases (And Which Ones Don’t)

While CO remains off-limits, plants demonstrably process other airborne toxins — but effectiveness varies wildly by compound, concentration, and environment. Below is a peer-reviewed comparison of removal efficiency for common indoor pollutants, based on meta-analysis of 17 studies (including NASA, University of Georgia, and Wageningen University research):

Pollutant	Primary Source	Most Effective Plant(s)	Removal Efficiency^*	Key Limitation
Formaldehyde	New furniture, laminate flooring, adhesives	Snake Plant (Sansevieria trifasciata), Golden Pothos (Epipremnum aureum)	60–78% reduction in 24h (small chamber, 100 ppb)	Requires soil microbes — hydroponic setups show <7% efficacy
Benzene	Plastics, synthetic fibers, tobacco smoke	Peace Lily (Spathiphyllum wallisii), Gerbera Daisy (Gerbera jamesonii)	50–65% reduction in 24h (small chamber, 50 ppb)	Effectiveness drops >80% in real rooms vs. lab chambers (UGA, 2021)
Trichloroethylene (TCE)	Dry-cleaned clothes, paint removers	Chrysanthemum (Chrysanthemum morifolium)	72% reduction in 24h (small chamber, 30 ppb)	Plant shows phytotoxicity above 100 ppb — dies before removing high concentrations
Carbon Monoxide (CO)	Fuel combustion (furnaces, stoves, generators)	None — no plant demonstrates measurable uptake	0% — no detectable reduction in any controlled study	CO binds irreversibly to hemoglobin in humans but has no biological interaction with plant enzymes
Carbon Dioxide (CO₂)	Human respiration, poor ventilation	Areca Palm (Dypsis lutescens), Rubber Plant (Ficus elastica)	10–15% reduction per plant/hour (in sunlit rooms)	Only during daylight photosynthesis; negligible at night

^*Based on standardized chamber tests (1m³ volume, 24-hour exposure). Real-world room-scale efficacy is 10–20% of lab results due to air mixing, surface adsorption, and HVAC systems (University of Georgia, 2021).

Frequently Asked Questions

Can any plant — even rare or tropical species — absorb carbon monoxide?

No. Extensive screening of over 200 plant species — including Dracaena cinnabari (Socotra dragon’s blood tree), Welwitschia mirabilis, and Rafflesia arnoldii — found zero CO uptake capability. This is universal across angiosperms, gymnosperms, and ferns. Evolutionarily, plants never developed CO metabolism because atmospheric CO concentrations remained below 0.1 ppm for 300 million years — too low to select for such a trait.

My CO detector went off, then quieted after I watered my plants. Does that mean they’re working?

No — this is almost certainly coincidence or instrument artifact. CO detectors use electrochemical sensors that can temporarily desensitize after high-concentration exposure or fluctuate with humidity/temperature shifts. Watering plants raises local humidity, potentially triggering sensor drift. Always treat a CO alarm as a genuine emergency: evacuate immediately, call 911, and have professionals inspect appliances — never assume plants resolved the issue.

Are there any ‘CO-resistant’ plants I should avoid near gas appliances?

There’s no such thing as CO-resistant plants — all are equally unaffected by CO exposure. However, avoid moisture-loving species (e.g., Boston fern, maidenhair fern) near furnaces or water heaters, as excess humidity accelerates metal corrosion. Also avoid fast-growing vines like English ivy on exterior flues — they can obstruct venting. Prioritize low-maintenance, drought-tolerant plants (snake plant, ZZ plant) in utility areas for practicality — not air cleaning.

What’s the fastest way to remove CO from a room if the alarm sounds?

Immediate evacuation is the only safe action. Once outside, call emergency services. Do NOT attempt DIY removal: opening windows helps, but CO disperses slowly (half-life in air is ~4–6 hours). Professional remediation requires combustion analysis, flue inspection, and appliance repair. Never re-enter until cleared by fire department or certified technician — CO can linger in wall cavities and ductwork.

Does activated charcoal or bamboo charcoal remove CO?

No. Activated charcoal effectively adsorbs VOCs, odors, and some heavy metals, but its pore structure doesn’t bind CO molecules. CO requires catalytic oxidation (like in car catalytic converters) or specialized metal-organic frameworks (MOFs) — neither present in consumer charcoal products. Relying on charcoal bags for CO protection is dangerously ineffective.

Common Myths

Myth #1: “Snake plants absorb CO at night.”
False. Snake plants perform Crassulacean Acid Metabolism (CAM), opening stomata at night to uptake CO₂ — not CO. Their nocturnal gas exchange involves only CO₂ and O₂. CO remains entirely uninvolved.

Myth #2: “More plants = safer air, especially for babies and pets.”
While plants improve humidity and reduce some VOCs, stacking dozens of plants won’t lower CO risk. In fact, overcrowded rooms with poor ventilation may trap CO more effectively. For infants and pets — who are more vulnerable to CO due to higher metabolic rates — reliance on plants instead of alarms is particularly hazardous.

Conclusion & Your Next Step

Indoor how does indoor plants get carbon monoxide reveals a critical gap between popular belief and botanical reality: plants play no role in CO mitigation. This isn’t a shortcoming of horticulture — it’s a testament to evolutionary specialization. Plants evolved to manage CO₂, O₂, and water vapor, not industrial combustion byproducts. Confusing these roles puts lives at risk. So today, take one concrete action: grab your phone and check the manufacture date on every CO alarm in your home. If any unit is older than 5 years, order replacements immediately — UL-certified models cost under $35 and are the single most effective CO defense available. Then, place your snake plant proudly on the living room shelf — not as a gas filter, but as a vibrant, proven ally against formaldehyde and a symbol of thoughtful, science-informed living. Your lungs — and your loved ones’ — will thank you far more than any myth ever could.