A prerequisite for the awarding of the GUT Publisher's Mark is membership of the Association of Environmentally-friendly Carpets. The GUT members undertake to comply with the environment-technical standards of production set by GUT. Both the production areas and the products are subject to regular monitoring by independent bodies.

GUT product testing covers four different areas:

• Bans on use. Cancer-causing materials must not be used.
• Testing for harmful substances. Harmful pesticides must not be detectable in the product.
• Emission test. Materials causing cancer or suspected of causing cancer must not be emitted.
• Smell test. The commodity tested shall only exhibit a low intensity new smell, typical of the product.

Currently there are no legal regulations governing materials brought into closed rooms.

Over the last few years the limits have been continually reduced and have reached a level today, which would make it reasonable to assume that there will be no further reduction. This is also the case because the value of 300 µg/m³ corresponds to the standard value of 300 µg/m³ for air in closed rooms recommended by Prof. Seifert, which is the target value in the case of permanent residence in the closed room. As testing is carried out on new products and the behaviour in decay is well known, falling short of the GUT limit automatically means that the tested article is generally recognised as safe indoors.

Following an application by the manufacturer, the test is carried out on freshly packaged goods. All commodities from one manufacturer are gathered together into groups of commodities under set criteria. 10% of currently listed commodities are subjected annually to a full test. Here every commodity group shall be recorded on the basis of at least one commodity. If there are no objections here, the validity of the licences concerned shall be extended for one year.

GUT carries out annual market checks alongside direct controls. Here commodities are selected in accordance with a previously set pattern (selection of such commodities - to be identified via the GUT Number -, which have not been covered in the direct controls).
GUT has drawn up an environment manual for member companies covering all the relevant activities of production.

It is established by one of the test bodies that a limit has been exceeded, a second analysis is automatically undertaken to ensure that no error of measurement or any other cause of trouble has led to the negative result. When the findings have been confirmed, the GUT Number is first of all cancelled and the manufacturer is invited to investigate the cause in co-operation with the testing body. If the cause can be established, a new sample is examined and the GUT Number reactivated once the test has been passed. The number of secondary tests shall in any case be increased from 10% to 15%. If the cause cannot be established or removed, the GUT licence loses its validity.

The companies are obliged to carry out emission tests at regular intervals and submit the results of these tests to the GUT.
All environment-related stages of production are covered in an in-house form. The GUT official uses this and the test certificates as a basis for his annual visits and technical support on site.