Chemical Agents

Chemical Agents are enemies who appear in later waves in Call of Duty: Modern Warfare 3 ' s Survival Mode. These enemies appear in Tier 2, 3, and 4 maps.

Overview
They have small green canisters on their backs that emit gas, which does no damage but slows the player and blurs the player's screen. These canisters make the click as a claymore so some players do confuse the two. The only time these canisters are deadly is when an already injured player tries to run away from enemies. They are usually placed by armories and or near the player. They also emit gas on death. They appear to have little armor. This is shown by the fact that they are particularly weak against most weapons, being of the same health as a medium trooper. They also appear to have gas surrounding them, which can allow a player to spot them before they set them off. The canisters themselves appear to not have any sort of sensor visible on them, and it just blows up when a player gets near it, releasing a sizable amount of gas. Another way to notice them is that their weapons possess a distinctive sound, which is the Modern Warfare 2's PP2000's firing sound. Overlord will not inform a player about Chemical agents unless the wave they are deployed is either the first wave they appear in during the game, or they set down their chemical mines.

The gas seems to have no effect on other enemies, even those without gas masks. Chemical Agents have gas masks and something that looks similar to an oxygen tank, containing gas. Chemical Agents will always use the PP90M1. They do not appear to use grenades, as they rely on their allies to utilize ordnance against a player.

Chemical Agents pose threats when working with other agents or other units, and it appears that they are more of a support unit rather than the mainline units that come after a player aggressively, as Chemical Agents, along with Claymore Experts, appear to take their time, planting chemical mines and Claymores around the map before engaging the player. Compared to most units, Chemical Agents do not work in conjunction with any unit consistently, rather working with whoever is there to protect them from the player, allowing them to set the mines down in areas.

These units will be deployed at wave 13 on Tier Two maps, and later on tier three maps, and early on tier four maps, so players should prepare for the possibility of running into chemical bombs in choke points or armories. These units, whilst functioning identically to their Claymore planting counterparts, are apparently better armed, as the PP90M1 is more effective at range, compared to the PM-9 used by the Claymore experts. One thing the players should be aware of the fact that enemy forces will deploy Claymore experts at the same time as Chemical Agents on later rounds, or early rounds, depending on the map the player is on, so players should be cautious about where they go, as the chemical mines will only slow them down, but claymores will most likely kill a wounded player who runs away from pursuing enemies.

Trivia

 * Chemical agents are the only units not to appear in a tier one map, as Riot Shield Juggernauts will be deployed at wave 26 in a tier one map, and Armored Juggernauts will come into play at wave 30.
 * Chemical agents share their model with some Inner Circle members in the post-train-crash part of "Mind the Gap".