Discoloration differs under topic wet heat condition, and under dry-heat condition the usefulness, offers the wet heat discoloration Characteristic constituent and the wet heat discoloration indicator to detection of wet heat condition.The settlement means bismuth compound and sulfur chemical compound, being the wet heat discoloration Characteristic constituent which contains the binder and the organicity composition, the wet heat discoloration Characteristic constituent which features that resin acid value contains the resin of 50 or more as an aforementioned binder.According to the wet heat discoloration indicator which uses the wet heat discoloration Characteristic constituent of main invention of the effect, whether or not the wet heat condition which is suited for sterilization treatment the occasion where autoclave sterilization is executed is obtained it is possible to judge accurately whether or not or sterilization treatment completed securely under wet heat condition.課題 湿熱条件下と乾熱条件下で変色の程度が異なり、湿熱条件の検知に有用な、湿熱変色性組成物及び湿熱変色インジケータを提供する。解決手段 ビスマス化合物、硫黄化合物、バインダー及び有機溶剤を含有する湿熱変色性組成物であって、前記バインダーとして樹脂酸価が50以上の樹脂を含有することを特徴とする湿熱変色性組成物。効果 本発明の湿熱変色性組成物を用いた湿熱変色インジケータによれば、高圧蒸気滅菌を実施する際に滅菌処理に適した湿熱条件が得られているかどうか又は湿熱条件下で確実に滅菌処理が完了したかどうかを正確に判断することができる。
