Frost—resistant profile is a profile designed for use in areas with an average monthly air temperature in January below minus 20 °C (the control load during durability tests is minus 55 °C).

Form stability is the property of profiles to retain their shape under the influence of operational and other loads.

Durability of profiles is a characteristic (parameter) of profiles that determines their ability to maintain operational properties for a given period, confirmed by the results of laboratory tests and expressed in conditional years of operation (service life).

Durability, color characteristics (according to the coordinate method), the adhesion strength of the decorative coating with the base profile are determined according to the methods approved in accordance with the established procedure.

When determining the durability indicator, the values of low-temperature loads during testing should not be higher:

minus 45 °C — for normal profiles;

minus 55 °C — for frost-resistant profiles.

Resistance to the action of chemical media is determined according to GOST 12020 and methods approved in accordance with the established procedure.

The reduced resistance to heat transfer of profile combinations is determined according to GOST 26602.1.