Fire-retardants serve to improve the reaction-to-fire performance of solid timber or wood-based materials treated with them. Through treatment with the fire-retardant, the solid timber or wood-based materials can be used in areas in which use of building materials classified as not easily flammable ('schwerentflammbar') is required. The fire-retardant can be applied to the solid timber or wood-based materials in a downstream process through painting, spraying, dipping or vacuum–pressure impregnation.

Regulatory framework

Classification of the reaction-to-fire of construction products is relevant to ensure fulfilment of the regulatory safety levels, cf. Model Building Code (MBO), Sections 3 and 14 in conjunction with Section 26.

DIBt grants national technical approvals (abZ)/general construction technique permits (aBG) for fire-retardants for timber/wood-based materials to improve their reaction-to-fire performance unless the test methods set out for the granting of a national technical test certificate (abP) are applied (cf. MVV TB, Section C 3, no. C 3.4), because there are no Technical Building Rules nor generally recognised technical rules for such products/applications.

European Technical Assessments (ETAs) can also be issued for fire-retardants. For applications comprising fire-retardants, the relevant provisions of the federal states following MVV TB, Section A 2.2, no. A 2.2.1.2 referring to Annex 4, Section 14 apply.

Please refer to the Technical Building Rules, cf. in particular:

• MVV TB, Part A 2.2, no. A 2.2.1.2 'Regulatory requirements, assignment of classes, use of construction products, application of construction techniques'

• MVV TB, Section A 2.2, no. A 2.2.1.3 Classified building materials and components, execution rules (referring to DIN 4102-4:2016-05)