r/IndoorAirQuality

Ok so I've been wondering for a while why I feel so gassed at the gym. Lightheaded between sets, out of breath way faster than I should be, weirdly exhausted after easy sessions. I just figured I was out of shape.

Then I brought a CO₂ monitor.

Set it down, did my workout, checked back — the reading was stuck between 3,500 and 3,700 ppm the whole time. Not climbing, not spiking. Just sitting there. Which means the air was already that bad before I even walked in.

Quick context on what those numbers mean:

• Outdoor air is around 420 ppm
• Healthy indoor air should be under 1,000
• Above 1,400 your focus drops and breathing rate goes up
• Above 2,000 you get into headache / fatigue / dizziness territory

My gym was basically 9x outdoor levels. Almost double the headache zone. Wild.

It's a low-cost gym and I'm 90% sure they're running ventilation at the bare minimum to cut energy costs. So everyone in there is basically breathing recycled exhale for their entire session.

The monitor I used is one I actually built — getaeris.ca if anyone's curious. But honestly any decent CO₂ meter will do the job. Just check your gym. If you've been feeling gassed for no reason, it might not be you.

Went to see Devil Wears Prada 2 with my wife. Got there 50 minutes early, so we waited by the popcorn counter — crowded Friday night, people everywhere.

Set up my air quality monitor on the counter and let it run. The CO₂ climbed steadily the whole time we waited. By the time we walked into the actual theater (which was almost empty), the air in there was way better than the lobby.

I designed the monitor — it’s called the Aeris View, made it in Montreal: getaeris.ca

I just bought an older home, and have noticed the dust is uncontrollable. despite all our efforts of buying air purifiers(not nearly strong enough) so we bought industrial air scrubbers, and it just seems like the dist comes back in 3 days we've deep cleaned the house i have vacuumed the air for extended periods of time I have 2 intake fans constantly on sucking air out of the house replaced furnace filters monthly

Im worried long term always breathing this in will be a risk

I've been formulating home fragrance for a few years now and I'm constantly shocked at how much the industry gets away with. Most people assume a reed diffuser is just "scent in a bottle," but what you're breathing for 8+ hours a day matters. Here's the checklist I wish existed when I started:

Carrier oil disclosed - The base oil makes up ~70–90% of the bottle. If it just says "base" or "blend," that's a red flag. Look for specific oils: dipropylene glycol (DPG), fractionated coconut, or isopropyl myristate. DPG is petroleum-derived; not inherently unsafe, but worth knowing.

IFRA conformity claim - The International Fragrance Association sets safe-use limits for 170+ fragrance ingredients. Compliant brands will say "IFRA compliant" or "formulated to IFRA standards." No claim = no accountability.

No "fragrance" as a catch-all - Under EU regulations, 26 known allergens must be listed by name if present above 0.001% in leave-on products. If a label just says "fragrance" with no breakdown, assume they're hiding something — or they're simply not testing.

Phthalate-free statement - Phthalates (like DEP) are commonly used as fragrance fixatives and are classified as potential endocrine disruptors by the EPA. A good brand will explicitly state "phthalate-free." If they don't say it, ask them directly.
No synthetic musks (or disclosed) - Nitro musks like musk ambrette are banned in the EU. Polycyclic musks (like AHTN/Galaxolide) are still widely used and bioaccumulate in human tissue. IFRA hasn't banned them, but informed consumers increasingly avoid them.

VOC content or "low VOC" claim - Volatile organic compounds evaporate into the air at room temperature. California's CARB standards cap VOC limits in air fresheners at 3%. Some premium brands now publish actual VOC percentages - that's the gold standard.

Reed material disclosed - Rattan reeds are porous and diffuse evenly. Synthetic fibre reeds can release plasticisers as they absorb oil. Brands that care will specify the reed material. Most don't.

The honest truth: most labels won't pass all 7. But even passing 4–5 of these means the brand is paying attention. I'm not here to sell you anything — I just got tired of buying diffusers that were basically unregulated chemical dispensers sitting on my desk.

Happy to answer questions about any of these, or how to read a fragrance SDS (safety data sheet) if you want to go deeper.

TL;DR — Look for: named carrier oil, IFRA compliance, allergen disclosure, phthalate-free claim, synthetic musk transparency, VOC data, and reed material. If a label has none of these, it tells you everything.

Hi all,
We looked into whether houseplants can actually lower CO₂ indoors.Short version: they do absorb CO₂, but in typical home conditions (limited light, normal number of plants), the effect is very small. A lot of the “plants clean your air” idea comes from studies that don’t really reflect real living spaces. From what we found, ventilation still makes the biggest difference by far, and the biggest impact would be on humidity.

A blog article here if anyone’s curious:
https://aranet.com/en/home/blog/can-houseplants-lower-co2-at-home

Would be interesting to hear if anyone here has measured CO₂ changes with plants in the room.