Non-product raw material output will mostly be disposed of as solid waste. Only in those rare cases where the company’s product is gaseous (industrial gases, perfume), will it be found in the air. More common is a liquid product (beer, milk) that goes down with wastewater.
For a first estimate, company internal calculation percentages for scrap can be used to estimate the non-product output of raw materials. Eventually, with more detailed material flow balances, scrap percentages may need adjustment. The reasons why raw materials do not become products are manifold and well worth study.
Product returns, obliteration, repackaging for other countries or specified customer requests, quality control, production losses, spoilage, wastage, decay in storage, shrinkage, etc. are some of the causes of waste generation that call for measures to increase production efficiency, which may be profitable both from an economic and ecological point of view.