If you’ve been running through Marathon and skipping those yellow gas-filled rooms, you’re probably leaving some of the easiest loot in the game behind. Tox clear events look dangerous, they feel risky, and if you don’t understand how they work, they can absolutely ruin your run.
Once you know the system, these rooms become one of the fastest and most consistent ways to build value early in a match. Today, I’m going to break down exactly how tox clear events work, how to clear them efficiently, and how to turn them into reliable, low-risk loot every time you drop in.
What are Tox Clear events?
Tox clear events are special loot rooms scattered across most maps in Marathon. You’ll recognise them instantly by the thick yellow toxic gas filling the room.
As you approach, the icon on your HUD will shift from a question mark to a square, signalling that it’s an active event location.
These rooms are essentially locked behind a mechanic. The gas prevents you from safely looting, forcing you to either clear it properly or take damage trying to brute force your way through.
The key thing to understand is this: these are designed to be quick, high-efficiency loot opportunities — not long engagements.
How to clear the gas (the intended method)
The main way to complete a tox clear event is by using a hazard override card. These keys are fairly common and can usually be found in side rooms, shelves, or higher-value loot areas across the map.
Once you have one, the process is simple:
Enter the tox clear room
Find the bright red computer console
Interact with it to repair it
Wait around 15 seconds for the gas to vent
Once the gas clears, the room becomes safe — but only for a limited time.
You’ll have about 30 seconds before the gas returns, which means you need to be quick and decisive with your looting.
How to loot efficiently
This is where most players lose value. Tox clear rooms are not about perfectly looting every container — they’re about speed and prioritisation.
Before you activate the console, take a second to scan the room and identify the best loot containers. Once the gas clears, move in a tight, efficient loop and grab everything you need without hesitating.
Most Tox Clear rooms only contain a handful of containers, so if you’re efficient, you can clear everything in under 20 seconds. The faster you move, the safer you are — and the less likely you are to get caught when the gas comes back.
The brute force method (mechanic’s kit)
If you don’t have a hazard override card, or you just want to play more aggressively, there’s another option. You can brute force tox clear rooms using a mechanic’s kit. When used, it instantly removes the toxic status effect and gives you around 30 seconds of immunity to the gas. This lets you ignore the console entirely and just run in, loot, and get out.
It’s fast and effective, but it comes at a cost. Mechanic’s kits are valuable, so you don’t want to waste them unless the loot is worth it or you’re pushing a high-tempo run.
Where to find tox clear rooms
Tox clear events appear across most maps and are commonly found around:
Major points of interest
Relay stations and compounds
High-value loot zones
Because of this, they can often become contested areas. While they are technically easy loot, they’re not always safe. If another player hears you clearing one, you can quickly find yourself in a fight.
Always stay aware of your surroundings while looting.
When you should (and shouldn’t) do tox clear
Tox clear rooms are best used early to mid-run. At this stage, your inventory still has space, and the extra salvage or materials can help you build momentum quickly.
They become much less valuable late into a run, when:
Your backpack is already full
You’ve likely had PvP encounters
The risk of getting caught is higher
At that point, the reward usually isn’t worth the risk. Think of tox clear events as efficient early-game boosts rather than late-game plays.
Pro tips to farm tox clear efficiently
If you want to consistently get value from tox clear events, keep these tips in mind:
Always carry at least one hazard override card
Learn the common spawn locations on your main map
Plan your loot path before activating the console
Prioritise speed over perfect looting
Stay alert for nearby players
Use mechanic’s kits strategically
Mastering these small details is what turns tox clear from a gamble into a reliable part of your run.
Tox clear events are one of the most overlooked systems in Marathon right now. They look dangerous, but once you understand them, they become one of the easiest ways to consistently build loot and improve your runs.
If you start integrating these into your route, you’ll notice your vault value climbing much faster — with very little extra risk.
And that’s the goal in Marathon. Efficient runs, smart decisions, and getting out with more than you came in with.