红棕色结晶性粉末。易吸湿。易溶于水，不溶于无水乙醇。210℃分解。最大吸收波长580nm。二甲酚橙作为指示剂常配成0.2%的水溶液使用，pH>6.3时，呈现红色；pH<6.3时，它呈现黄色；ph=pka=6.3时，呈现中间颜色。二甲酚橙与金属离子形成的配合物都是红紫色，因此它只适用于在pH<6的酸性溶液中。

中文别名：二甲苯酚橙;二甲酚桔黄，3，3′-双[N，N-二(羧甲基)氨基甲基]邻甲酚磺酰酞，邻甲酚磺酰酞-3，3′-双甲基亚氨基二乙酸，二甲酚橙四钠盐;XO指示剂

Xylenol orange is an organic reagent, most commonly used as a tetrasodium salt as an indicator for metal titrations. When used for metal titrations it will appear red in the titrand and yellow once it reaches its endpoint. Historically, commercial preparations of it have been notoriously impure, sometimes consisting of as little as 20% xylenol orange, and containing large amounts of semi-xylenol orange and iminodiacetic acid. Purities as high as 90% are now available.

常温,12个月