Why is `C Cl_(4)` used in fire extinguishers while `CS_(2)` cannot be used?

Explanation

`C Cl_(4)` is a heavy non-combustible liquid. When its vapour are sprayed on fire, they form and envelope arround fire and donot allow the air to come in its contact. Therefore `C Cl_(4)` is used at a fire extinguisher under the name pyrene. `CS_(2)` is a highly combustible liquid and, thus, cannot be used a fire extinguisher.
`CS_(2)+3O_(2)rarrCO_(2)+2SO_(2)`