I suggest you create an expense account to track the amount you lose for a waste inventory item. What you need to do next is to add a service to the Products and Services page.
Follow these steps to create the expense account:
Click the Accounting tab.
Set the Account Type to Expenses, then choose whichever is closest to the Detail Type.
Enter a name.
Hit Save and Close.
Next up, you need to create a service to link this expense account. Here's how:
Highlight the Sales tab.
Select Products and Services.
Enter a name.
Change the Income account to the expense account you created above.
Click Save and close.
At this point. you can create a sales receipt with the service you recently created. Under the Amount column, type in the total amount for the damaged inventory items in question. This will count as a loss for your business.
You may need an additional app to do so. For any output of a process, you can specify the output item as waste. Based on the percentage of waste items and non-waste items, the app will calculate a yield for your process. This helps you to evaluate materials from different suppliers, for example, to determine which gives you the best outputs in your manufacturing. Waste items go into inventory like any other inventory item, so that they can be tracked and used later as needed.