- Primary Subject: Marathon
- Key Update: Tox Clear events require players to disable toxic gas using a Hazard Override Card to safely loot sealed rooms
- Status: Confirmed
- Last Verified: March 9, 2026
- Quick Answer: To complete a Tox Clear event in Marathon, use a Hazard Override Card at a nearby red terminal to vent toxic gas, giving about 30 seconds to safely loot the room.
While exploring the maps of Marathon, players will occasionally encounter special map events that offer additional rewards if completed.
Most of these events revolve around defeating enemies or interacting with objects in the environment, but the Tox Clear event is a little different.
Instead of traditional combat challenges, these events test players by placing them inside sealed rooms filled with dense yellow toxic gas that continuously deals damage.
Since the gas steadily inflicts heavy poison damage, players cannot safely loot the room unless they disable the hazard or find a way to withstand the damage long enough to collect the items.
Where Can You Find Tox Clear Rooms?
Tox Clear rooms can appear across several areas of Tau Ceti IV and are usually marked on the player’s HUD.
As you approach the location, the event icon will change to indicate that it is a Tox Clear event, helping you identify the hazardous room nearby.
Inside these chambers are several trunks and loot containers that often contain useful rewards. Players can find crafting materials such as salvage, faction upgrade resources, implants, cores, valuables, and occasionally more valuable equipment or weapons depending on the random loot generated during the run.
These rewards make Tox Clear rooms worthwhile to enter, as long as you have the equipment to survive the toxic gas.
How Do You Safely Complete the Tox Clear Event?
The safest way to complete the event is by using a Hazard Override Card, a special key item in Marathon that can be found while looting containers around the map, such as shelves in side rooms, storage areas, or even on defeated players.
Since Hazard Override Cards behave similarly to other keys in the game, players can extract with them and store them in their vault to use during a later run.
This makes it helpful to carry one into a match if you plan to tackle a Tox Clear event, as there is no guarantee you will find one during the same expedition.
After obtaining a Hazard Override Card, the next step is to locate the red computer terminal or laptop that controls the gas ventilation system.
This terminal usually appears somewhere close to the toxic chamber itself. In some cases it will be positioned just outside the building containing the gas-filled room, while in others it may spawn a short distance away within the same immediate area.
The laptop can be identified by its bright red casing and a symbol that matches the gas extraction devices inside the toxic room.
Interacting with this terminal while carrying a Hazard Override Card will activate the system and begin venting the toxic gas from the chamber.
The process takes a short moment to complete, after which the room becomes temporarily safe to enter. However, the ventilation does not last very long.
Once the gas clears, players typically have about 30 seconds before the toxic fumes begin filling the room again.
During this brief window, it is important to move quickly and open the available loot containers before the hazard returns.
Fortunately, most Tox Clear rooms contain only a handful of trunks and other moderate-value containers, meaning players can usually grab the loot quickly if they move efficiently.
Still, it is important to remain aware of your surroundings since other players may also be attracted to these high-value locations, which can turn the event into a dangerous PvP encounter.
Can You Complete Tox Clear Without a Hazard Override Card?
Although using a Hazard Override Card is the safest and intended method for completing the event, it is not the only option available.
Players can technically enter the toxic room without disabling the gas, but doing so immediately exposes them to a damaging toxin effect.
This poison gradually drains health and also weakens the effectiveness of healing items, making the situation extremely risky.
If the damage continues long enough, it can easily lead to death. There are a few ways to mitigate this risk if you decide to force your way into the room.
One of the most useful items is the Mechanic’s Kit, a consumable that removes the toxin status effect and provides temporary immunity to toxic damage for a short duration.
This allows players to briefly enter the gas-filled room and collect the loot without immediately taking damage.
Another helpful strategy involves using strong healing abilities or support tools such as the Triage shell’s medical drone, which can provide additional healing to offset the toxin damage while looting.
However, both methods require careful timing and preparation, since the toxic environment can easily overwhelm players who are not ready.
For more like this, stick with us here at Gfinityesports.com, the best website for gaming guides.