1. Water makes basic effect of extinguishing that's

cooling of burning subjects

Water extinguishing flaws are:

water freezing on negative temperatures;
brings damages for equipment and buildings;
person extinguishing electrical equipment can be shocked;
water badly moistens some filamentary (волокнистый) and solid substances;
water isn’t effective for extinguishing of some material like oil, oil products, metals.

2. Foam can be chemical (carbon dioxide bubbles) and air-mechanical (air bubbles).

Foam extinguishing effect is cooling of the upper layer and isolation of burning material from the air.
The foam is not applied for extinguishing of
electrical equipment under voltage and
active substances (potassium (K), sodium (Na), carbon bisulfide (H2S)) which react with CO2

Fire extinguishers

3. Carbon dioxide (CO₂) removes oxygen to stop a fire and it is used generally for extinguishing of electrical equipment.

• It is environmentally friendly and leaves no residue.

• Extinguishers with CO₂ are usually used in contamination-sensitive places (computer rooms, labs, food storage areas)

!BUT: Carbon dioxide extinguishing in closed rooms increases concentration of CO₂ dangerous for life.

5. Dry chemical (powder) extinguishers

+Powder cloud creates protection from heat radiation and works to interrupt the chemical reaction of fire.

In the air of closed rooms high dust content appears
The powders have weak cooling effect that makes possible repeated inflaming.

Fire Class	Geometric Symbol	Pictogram	Intended Use	Mnemonic
A	Green Triangle		Ordinary solid combustibles	A for "Ash"
B	Red Square		Flammable liquids and gases	B for "Barrel"
C	Blue Circle	in	Energized electrical equipment	C for "Current"
D	Yellow Decagon (Star)	ik	Combustible metals	D for "Dynamite"
K	Black Hexagon 1	S	Oils and fats	K for "Kitchen"