The Radiation Protection Act (StrlSchG) lists the relevant mineral primary raw materials in Annex 9 and the relevant residues in Annex 1.

If you duly notified the competent authority that a product exceeds the permissible levels and the competent authority has ordered measures for its use, you as the obligated party must inform the owner, the designer and the contractor within the meaning of the Building Code of the relevant federal state of any restriction ordered. If these persons are not known to you, the construction product must be provided with accompanying documents clearly stating the applicable use restrictions (cf. Section 135(4) StrlSchG).

One possible measure is to restrict the area for which the construction product can be used e.g. only for walls, floors or ceilings.

For construction products consisting of different admixed components (e.g. concrete, bricks), the proportion of the relevant ingredients can be limited to comply with the activity index of the resulting construction product.

If construction products are not used for the construction of buildings with indoor spaces regularly occupied by people, they can be placed on the market without the need to determine the specific activities mentioned above, but only with the aforementioned use restriction.

The manufacturer or the person placing the construction product on the market must notify the competent authority immediately if the effective dose likely to be emitted by the construction product exceeds the reference level.

Pursuant to Section 135(3) StrlSchG, the competent authority may order restrictive measures or prohibit the use of the construction product within one month after receipt of this notification.

The reference level for the effective dose from external exposure of members of the public in indoor spaces regularly occupied by people to gamma radiation from construction products is 1 millisievert per calendar year in addition to the effective dose from external exposure outdoors.

The reference level of 1 millisievert per calendar year is deemed to be complied with if the activity index determined does not exceed the level of 1.

External radiation exposure, which also includes terrestrial radiation, is caused by naturally occurring radioactive substances that are present in the soils and rock layers of the earth's crust and vary in concentration regionally. These stones and soils are important mineral raw materials for construction. Thus, radionuclides contained therein can transit into the construction products and contribute to external radiation exposure for persons using the respective buildings.

Pursuant to Section 5(5) of the Radiation Protection Act (StrlSchG), an indoor space regularly occupied by people is defined as follows:

'Indoor space regularly occupied by people: indoor space intended for more than just a passing stay of members of the public, for example in a school, hospital, kindergarten or for living.'

Section 5(6) of the Radiation Protection Act (StrlSchG) defines construction products as follows:

'Construction products: building materials, kits, components and installations manufactured to be permanently incorporated as wall, floor or ceiling constructions, including their claddings, of indoor spaces regularly occupied by people in buildings. This does not include finished products used for a small area and in a small amount, such as repair mortars and grouts.'

Before a construction product can be placed on the market, the specific activity of the radionuclides radium-226, thorium-232, or its decay product radium-228, and potassium-40 must be determined.

The specific activity of radium-226, thorium-232 and potassium-40 is measured by means of gamma spectrometry (DIN CEN/TS 17216:2018).

The following test standards/instructions containing specifications on how to prepare test specimens/test quantities are considered suitable reference methods by DIBt:

• DIN CEN/TS 17216:2018: Construction products – Assessment of release of dangerous substances – Determination of activity concentrations of radium-226, thorium-232 and potassium-40 in construction products using semiconductor gamma-ray spectrometry
• Measuring instructions for monitoring radioactivity in the environment and for detecting radioactive emissions from nuclear installations (only available in German: Messanleitungen für die Überwachung der Radioaktivität in der Umwelt und zur Erfassung radioaktiver Emissionen aus kerntechnischen Anlagen)
  Published by: German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety

or

• DIN EN ISO 18589-3:2007: Measurement of radioactivity in the environment – Soil – Part 3: Measurement of gamma-emitting radionuclides

Significant deviations from the measurement method used must be stated and justified in detail.

The Deutsche Akkreditierungsstelle GmbH or DAkkS (German website) is the national accreditation body of the Federal Republic of Germany. It acts under Regulation (EC) No 765/2008 and the Accreditation Body Act (AkkStelleG) in the public interest and is the sole accreditation provider in Germany. To obtain a list of test laboratories that you can contact to have the specific activity of the relevant radionuclides determined, you can use the DAkks database for accredited bodies.

The activity index must be calculated in accordance with Annex 17 of the Radiation Protection Ordinance (StrlSchV).

The Federal Office for Radiation Protection (BfS) pools expertise in the field of radiation protection, including effects and risks of ionising and non-ionising radiation, radiological accident management, monitoring of environmental radioactivity and medical and occupational radiation protection.