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General
Systematic name	3,3′-Bis[N,N-bis(carboxymethyl)aminomethyl]-o- cresolsulfonephthalein tetrasodium salt
Molecular formula	C31H28N2O13SNa4
Molar mass	760.59 g mol−1
CAS number	[6318-43-7]
Properties
Solubility in water	Fully miscible
Melting point	195°C (368 K)
Flash point	Greater than 93.3°C (200°F)
R-phrases	, , , , ,
S-phrases	, , , , ,
NFPA 704
Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa)

Xylenol orange is an organic reagent, most commonly used as a tetrasodium salt as an indicator for metal titrations. 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.