FIELD: units for monitoring temperature and time conditions of steam sterilizers, manufacture of indicators changing their color at integral action of definite temperature and pressure of water vapor during preset interval of time. SUBSTANCE: composition contains mixture of aminosulfonic acid (ureasulfonate, or thiourea, or guanidine) registering components which is just pH-indicator or mixture of pH-indicators changing its color in acid zone. Urea-sulfonic acid (sulfuric acid), sulfamic acid, sulfanilic acid or metanilic acid may be used as aminosulfonic acid, Basic urea sulfonates (sulfanilurea, urasulfane, etc.) or thioreas (badional, etc.) or guanidine sulgin, etc. ) as well as acid urea sulfonates (sulfanilic acid urea, etc.) or thioreas (sulfamic acid thiourea, etc.) or guanidine (sulfamic acid guanidine, etc. ) may be used salts aminosulfonic acid. One of the following pH-indicators or their mixture may be used as registering component in proposed composition; bromophenol blue, methyl yellow, methyl orange, bromochlorophenol blue, Congo red, alizarin red and bromocresol green. EFFECT: avoidance of toxic components in reaction products; reduced rate of hydrolysis, if necessary, of components; retaining final color of composition during extended period of time. 8 cl
