As a conclusion from the data presented in reference 4 on the temperatures of sodium polyhydrofluoridesdecomposition, the only sufficiently accurate values are the ones presented for NaF·HF. The values ofdecomposition temperatures Тdec of all the other sodium polyhydrofluorides are approximate. In addition, if thecompounds have more than two molecules of HF, these values have rather problematic magnitude. A similar pictureoccurs in case of polyhydrofluorides of other alkali metals (AM – alcali metal). The reference 4,8 lists thedecomposition temperatures approximately equal to ~298 К for such compounds as NaF·3HF, NaF·4HF, KF·3HF,KF·4HF, CsF·3HF, CsF·4HF. We believe that the researchers took this value for the decomposition point because ofsufficiently fast decomposition of polyhydrofluorides and considerable growth of pressure of evolved HF.