The present invention relates to a system, and the method of application thereof, for washing and decontamination comprising nebulizing means (8) of a mixture of at least one first gas and at least one first liquid, and pressurizing means (1) of said first gas, wherein said pressurizing means (1) are in fluid communication with a first pressure-regulating valve (3) and with a second pressure-regulating valve (4), the first pressure-regulating valve (3) being in fluid communication with a first pressurized tank (5) through first inlet means (31) of said first gas, the first pressurized tank (5) being configured to contain the first liquid, and comprising first outlet means (30) of said first liquid to the nebulizing means (8) through a first valve (6), at a first pressure that is greater than atmospheric pressure, and wherein the second pressure-regulating valve (4) is in fluid communication with said nebulizing means (8), and is configured to pressurize the gas at a second pressure that is greater than atmospheric pressure.
