This is a highly dangerous and potentially explosive combination. Here's why:

* Chlorine is a strong oxidizer: It readily reacts with other substances to release oxygen, creating a highly reactive environment.

* Petrol (gasoline) is highly flammable: It contains hydrocarbons that ignite easily.

Mixing chlorine and petrol can lead to:

* Fire: The chlorine's oxidizing properties can cause the petrol to ignite spontaneously.

* Explosion: The rapid reaction between chlorine and petrol can generate significant heat and pressure, leading to a detonation.

* Toxic fumes: The reaction can produce toxic and harmful gases, such as chlorine gas and carbon monoxide.

Safety Precautions:

* Never mix chlorine and petrol under any circumstances.

* Store chlorine and petrol separately in well-ventilated areas.

* Always follow the manufacturer's instructions for handling and storing these substances.

* In case of accidental mixing, evacuate the area immediately and call emergency services.

If you suspect that chlorine and petrol have been mixed, do not attempt to handle the mixture yourself. Seek professional help immediately.