Agent Name

p-Toluenesulfonic acid

CAS Number




Major Category

Other Classes


Toluene sulfonic acid; 4-Methylbenzenesulfonic acid; 4-Toluenesulfonic acid; Benzenesulfonic acid, 4-methyl-; Benzenesulfonic acid, methyl-; Cyclophil P T S A; Cyzac 4040; Eltesol; K-Cure 040; K-Cure 1040; Kyselina p-toluenesulfonova [Czech]; Kyselina p-toluensulfonova [Czech]; Manro PTSA 65 E; Manro PTSA 65 H; Manro PTSA 65 LS; Methylbenzenesulfonic acid; Nacure 1040; TSA-HP; TSA-MH; Toluenesulfonic acid; Tosic acid; p-Methylbenzenesulfonic acid; p-Methylphenylsulfonic acid; p-Toluene sulfonate; p-Toluolenesulfonic acid; p-Tolylsulfonic acid; Toluene-4-sulphonic acid; ar-Toluenesulfonic acid (8CI); [ChemIDplus] UN2583; UN2585 (not more than 5% free sulfuric acid)


Benzenesulfonic Acid Derivatives


Colorless hygroscopic solid; [ICSC] Colorless to black solid with no or little odor; [CHRIS] Off-white crystals; [Integra MSDS]


Used in the chemical industry as a catalyst; also used in the manufacturing of textile dyes, drugs, cleaning agents, polymers, and paints; [HSDB] Used in photography (color bleaching); [] Used as a catalyst (with applications including resins in foundry cores), as a curing agent for resins, as a descaling agent (industrial metal cleaners), in electroplating bathes, plastics, dyes, pharmaceutical intermediates, food packaging adhesives, and as a coupling and wetting agent; [EPA ChAMP]


Corrosive to skin; [Quick CPC] High inhalation exposure of dust may cause pulmonary edema; [ICSC] A severe skin and eye irritant; [CHRIS] Absorbs moisture from air forming a highly acidic liquid; Commercial grades are aqueous solutions (minimum 65% with a maximum of 0.8% free sulfuric acid) and solids (90% and 95% pure); Highly irritating or corrosive to skin and eyes of rabbits; Not a skin sensitizer in guinea pig maximization test; [IUCLID] Causes severe burns; Inhalation may cause corrosive injuries to upper respiratory tract and lungs; Harmful by ingestion and inhalation; [Integra MSDS]

Exposure Assessment
Vapor Pressure

2.7E-6 mm Hg

Explanatory Notes

Melting point = 106-107 degrees C; [HSDB] The Guide in the Emergency Response Guidebook is for "Aryl sulfonic acids, solid, with more than 5% free sulfuric acid."

Reference Link

ICSC: p-Toluenesulfonic acid (max. 5% sulfuric acid)

Adverse Effects
Toxic Pneumonitis



Skin Burns

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information


Chemical Information

Search ChemIDplus

Related Information in HazMap

Industrial Processes with risk of exposure: