The quality assurance specifies inspections that in most cases are more extensive than those usually done in the production facilities. For example, biological parameters such as the absence of weeds and growth inhibitors are an integral part of the inspections. The emphasis placed on substrate structure is also unusual. Similarly, the quality assurance calls for retained samples that will allow for inspecting the quality of already delivered substrates as needed. The Quality and Testing Regulations also include the obligation to declare key properties of the substrates.
All the above underlines the advantages quality assurance offers to consumers and is consequently a selling point for producers.