The “usage type” chemical inventory refers to the amount (quantity) of chemicals used or consumed in the facility during a month. 

In cases where a chemical was not used during the reporting month, it is still essential to report the chemical with zero usage in the chemical inventory upload to generate the Performance InCheck Report. This ensures that all input chemicals at the facility are captured in the report.

The advantage of using the usage type inventory is that it supports Root Cause Analysis (RCA) for non-conformities in outputs such as wastewater, sludge, air emissions, and products.

A simple method to calculate the usage quantity can be done using the formula below. (This formula captures not only the inventory that is used but also delivered and in stock).

Usage quantity = (Amount of the chemical product in stock at the start of the month + Amount of chemical product delivered in that month) – Amount of chemical product in stock at the end 

See examples on the Suppliers Roadmap to Zero