Abstract
<jats:p>Wood is a versatile building material that is actively used in construction. Considering its properties, wood is a combustible material and requires measures to improve its fire safety. This indicator is achieved directly by the use of flame retardants (hereinafter - OS). Today, the OS certification and assessment system is based on laboratory studies, while not taking into account the real conditions affecting the OS over many years of operation, such as climatic. The impact of negative factors on the OS may lead to its non-compliance with the stated requirements and established requirements. The paper presents the results of a study of the influence of the main climatic factors (increased air humidity, natural ultraviolet radiation (hereinafter - UV radiation), negative temperatures) on the fire-retardant effectiveness of impregnating compositions from different manufacturers intended for wood. Thus, it was found that the prepared samples treated with one of the five compositions after exposure to fire lost weight from 7.6 % to 10.8 %, which did not meet the declared parameters. It was also found that the most significant impact on the OS is exerted by the operating conditions of treated wood in conditions of high humidity. Based on the results obtained, recommendations were proposed for the use of OS operating in conditions of high humidity and the importance of annual monitoring of the state of fire retardant coatings was confirmed.</jats:p>