Propane in Your Van: The CO PPM Numbers You Must Know

Cooking with propane inside a van feels normal. Millions of van lifers do it every day. But carbon monoxide — a colorless, odorless gas — builds up fast in a small enclosed space. According to the CDC, CO kills approximately 400 Americans every year and sends over 100,000 to emergency rooms. In a standard cargo van with poor ventilation, a single propane burner can push CO levels past 70 PPM in under 10 minutes. That's the number where the danger becomes real. This post breaks down exactly what CO PPM levels mean for van life propane safety, when to worry, and what you can do right now to protect yourself on the road this summer.

What Does CO PPM Actually Mean for Van Lifers?

PPM stands for parts per million. It measures how many molecules of carbon monoxide are mixed into every million molecules of air. A higher PPM means more CO — and more risk. Think of it like food coloring in water. A drop in a swimming pool is fine. A drop in a glass of water is a problem. Your van is a very small glass. The CDC says the air you breathe every day has about 0.1 PPM of CO — essentially nothing. OSHA sets its safe work limit at 50 PPM over an 8-hour workday. The CPSC says CO alarms built to the UL 2034 standard don't have to sound until CO holds at 70 PPM for 1 to 4 hours — or 150 PPM for 10 to 50 minutes. That means a standard alarm-only detector could stay silent while the air in your van is already making you sick. That's not a flaw in the alarm — it's how the standard was written. But for a 60-square-foot van interior, those thresholds aren't protective enough. See Carbon Monoxide PPM Levels Explained: What's Safe, What's Dangerous for a full breakdown of what each CO level does to your body. Takeaway: PPM is the number that tells you how much CO is in your air — and most van lifers never see it because their detector has no screen.

How Fast Does Propane Cooking Build Up CO in a Van?

Propane burns clean when it has plenty of oxygen. But your van doesn't have plenty of oxygen — especially with the doors closed and a vent fan off. When propane combustion is incomplete, it produces carbon monoxide instead of the safer carbon dioxide. The smaller the space and the less airflow, the faster incomplete combustion happens. A standard full-size cargo van has roughly 200 to 250 cubic feet of interior space. One medium propane burner running for five minutes in that sealed space can produce enough CO to push levels past 35 PPM — the point OSHA considers the upper safe limit for continuous exposure. Keep cooking for 15 to 20 minutes with windows cracked but no active ventilation, and you can easily hit 100 to 200 PPM. At 200 PPM, the CDC says a healthy adult will experience headache, dizziness, and nausea within two to three hours — and someone asleep may never notice the symptoms escalating. Van lifers often cook, eat, and then go to sleep in the same small space. The CO that built up during dinner doesn't just disappear. See Carbon Monoxide Poisoning While Sleeping: The Real Risk for why sleeping through CO exposure is especially dangerous. Takeaway: Propane cooking in a van can reach dangerous CO levels faster than most people expect — especially when ventilation feels adequate but isn't.

What CO PPM Numbers Should Van Lifers Actually Watch?

Here are the numbers that matter — and what to do at each one. Below 35 PPM is the safe zone. OSHA and the CDC consider this acceptable for ongoing exposure. If your detector shows a reading here while cooking, your ventilation is working. 35 to 70 PPM is the caution zone. You won't feel sick right away, but something is off. Open a door, turn on your roof fan, and find the source. Don't sleep in this range. 70 to 150 PPM is the alarm zone. This is where the CPSC says standard CO detectors should eventually trigger. You'll likely feel a headache coming on. Get outside immediately and leave doors open. Above 150 PPM is the danger zone. According to UL 2034 testing standards, at 150 PPM a CO alarm must sound within 50 minutes. But by then, symptoms can be severe. NIOSH classifies 1,200 PPM as immediately dangerous to life and health — a level that can be reached in a sealed van with a running generator in minutes. The problem is that alarm-only detectors give you a binary signal: fine or alarm. They can't tell you you're sitting at 60 PPM for three hours straight. A detector with a live PPM display changes that completely. The 70 PPM Standard Was Designed to Alarm Late — Here's Why That's a Problem explains why the 70 PPM standard was designed for homes, not vans. Takeaway: The PPM numbers that matter most for van lifers are 35, 70, and 150 — each one signals a different level of urgency.

Does Propane Itself Set Off a CO Detector?

This surprises a lot of van lifers. Raw propane — the gas leaking from a loose fitting or a forgotten valve — does not trigger a standard CO detector. CO detectors only measure carbon monoxide. They do not detect propane, methane, or natural gas. That matters because a propane leak before any flame is lit is actually the more explosive risk. Propane is heavier than air, so it sinks to the floor of your van and pools there. If it reaches your van's electrical system or an ignition source, the result isn't CO poisoning — it's fire or explosion. See Is Carbon Monoxide Heavier Than Air? Where CO Actually Collects for how CO and propane behave differently in an enclosed space. A CO-only detector gives you no warning at all about a raw propane leak. That's a real gap for van lifers who use propane for cooking and heating. A 3-in-1 detector that monitors CO, methane, and propane separately protects you from three different threats instead of just one. Some van lifers also use propane heaters overnight in cold weather. That's arguably more dangerous than daytime cooking, because you're asleep and CO builds up slowly while your body can't respond. If you run any propane appliance overnight, a live PPM detector is not optional — it's essential. Takeaway: CO detectors don't detect raw propane — so a CO-only alarm leaves van lifers exposed to both an invisible gas leak and slow CO buildup.

What Should Van Lifers Do Right Now?

• Always run your roof vent fan on exhaust mode when cooking with propane — not just cracked windows.
• Check your current CO detector: does it show a live PPM number, or just an alarm light? If it's alarm-only, you're flying blind.
• Never use a propane stove or heater while sleeping — cook, ventilate for 20+ minutes, then close up for the night.
• Learn the 4 numbers: 35 PPM (safe limit), 70 PPM (caution), 150 PPM (alarm), 1,200 PPM (immediately life-threatening).
• If you run a propane heater overnight in cold weather, place a CO detector at sleeping height — about 4 to 5 feet off the floor.
• After any propane cooking session, open both doors for at least 10 minutes before closing up — even if everything 'seems fine.'
• Consider a 3-in-1 detector that monitors CO, methane, and propane — raw propane leaks won't trigger a CO-only alarm.

You've put real time and money into your van build. It deserves the same attention to air safety as everything else. A detector that only beeps doesn't tell you anything useful — you need to see the actual PPM number to know if your ventilation is working or if last night's dinner is still lingering in your air. That's exactly what the AirShield™ 3-in-1 Portable Carbon Monoxide Detector was built for. It shows live CO, methane, and propane readings on a bright OLED screen, runs on 100–240V so it works anywhere in the world, and carries full UL listing. If you're heading out this summer, it's worth having one on board before you leave. You can find it at airshield.store.