Item numbers for 'non-stock' or consumable items

In purchasing of non-stock consumable items, is it possible to avoid creation of item numbers?

For example, if we are purchasing an air-conditioner every year, the item specifications would change regularly (different model number, could be different brand) which would require a new item to be created. Or, for purchase of a ‘blue pen’, where we don’t need to track the specifications.

A consumable material is a material that is subject to a procurement transaction and whose value is recorded in the cost element or asset accounts. Consumable material is thus procured directly for an account assignment object. Examples of consumable materials are office supplies and computer systems or machines.

From SAP: Outlining Consumable Purchasing