With the mass balance method, current levels of harmful chemicals, such as hydrofluorocarbons and chlorofluorocarbons, can be calculated and best predictions of future levels formulated. This information enables environmental scientists to better evaluate the rate of global warming based on the usage of emissions that contribute to the depletion of the ozone layer.

The mass balance method is employed to determine the difference between the starting amount and the ending amount of a substance such as refrigerant gas. How much of the chemical was in daily use and how much of it was discharged into the air may then be determined.

Adding the amount of chemicals entering a process plus the different avenues used by those chemicals, for example waste or accumulation, we arrive at an equation used for the mass balance method. The end result equates to the final amount of substance entering the global atmosphere. If we use refrigerant gas as an example, we take the starting amount, transformation through the cooling process and the waste amount.

By using a mass balance method, a facility is tracking the amount of substances used for a specific function. It is broken down by how much enters the system, how much leaves the system and how much is stored within the system. This approach is used when it is necessary to account for pollutants.

Certain chemicals have been identified as harmful and contributors to the deterioration of the stratospheric ozone layer, air pollution and global warming. The EPA requires the use of the mass balance method to track chemicals such as methyl bromide, carbon tetrachloride, methyl chloroform, hydrofluorocarbons and chlorofluorocarbon.

In simple terms, the mass balance method can be defined as inputs = output plus accumulation. The mass balance method is critical in designing and analyzing processes, such as refrigerant gas as it moves its way through various systems, including air conditioning, heating ventilation and AC or refrigeration. Whatever substances or chemicals enter or leave a system must be accounted for.

There is a strict reporting procedure under the mass balance method. Facilities must report venting of hydrofluorocarbons and chlorofluorocarbons, including total inventory at the beginning and end of the reporting period, any purchases and any capacity changes.

There are several factors used in the mass balance method. The type and number of cooling equipment machines that are used, the refrigerant type used in each system, leak rates and total refrigerant discharge. Mass flows that might otherwise have been difficult to measure are identified in the equation, such as evaporated substances or parts of a chemical reaction.