p-Xylene

Synonyms

1,4-Dimethylbenzene; 1,4-Xylene; 4-Xylene; Benzene, 1,4-dimethyl-; Chromar; Scintillar; p-Dimethylbenzene; p-Methyltoluene; p-Xylol; Benzene, p-dimethyl-; Xylene, p-; Xylene, p-isomer; [ChemIDplus] para-Xylene; [ICSC] Paraxylene; PX; [HSDB] UN1307

Category

Aromatic Solvents

Description

Colorless solid at low temperature; mp = 13-14 deg C; [Merck Index] Colorless liquid with a sweet odor; [CHRIS]

Sources/Uses

Permitted for use as an inert ingredient in non-food pesticide products; [EPA] Found in coal tar; Commercial xylene is a mixture of the o-, m-, and p- isomers; Used as a solvent, raw material, catgut sterilant, and in microscopy; [Merck Index] Used predominately to make purified terephthalic acid (PTA) and dimethyl terephthalate (DMT) which are used in polyester production; Also used as a solvent, for paints, in the printing trade, and in the production of di-paraxylene and herbicides; [HSBD]

Comments

A skin and eye irritant; May have CNS effects; An aspiration hazard by ingestion (may cause chemical pneumonitis); May have adverse effects on human reproduction or development, based on animal studies; [ICSC] May cause smarting and reddening of skin if spilled and allowed to remain on clothes; High vapor concentrations may cause mild smarting of eyes and respiratory system; May cause liver and kidney injury; [CHRIS] A local irritant; Inhalation of high concentrations may cause narcotic effects, severe coughing, and pulmonary edema; Ingestion may cause kidney and liver injury; [NTP] A skin irritant; Harmful by inhalation and skin absorption; May cause narcosis, lung irritation, chest pain, pulmonary edema, CNS depression, blood disorders, liver and kidney injury, and reproductive disorders; [Sigma-Aldrich MSDS] An OTO notation is recommended for p-xylene based on human and animal ototoxicity data." [2021 ACGIH] See "Xylene isomers."

Biomedical References

Xylenes (technical or commercial grades): 0.3 g/g creatine methylhippuric acids in urine at end of shift; [ACGIH TLVs and BEIs]

No

100 ppm

150 ppm

100 ppm

100 ppm

900 ppm

8.84 mm Hg

0.05 ppm

LC50 (rat) = 4,550 ppm4hr

Explanatory Notes

Odor threshold from CHRIS; The Guide in the Emergency Response Guidebook is for "Xylenes."

may ignite at ambient temp

Acute solvent syndrome

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Not classifiable

Not Classifiable

Diseases

Occupational diseases associated with exposure to this agent:

• Encephalopathy, chronic solvent
• Solvents, acute toxic effect

Processes

Industrial Processes with risk of exposure:

• Painting (Solvents)