Chloroxylenol (PCMX, 4-Chloro-3,5-Dimethylphenol) Storage & Tank Compatibility

Storing Chloroxylenol (PCMX, 4-Chloro-3,5-Dimethylphenol)? Start Here

Chloroxylenol, widely known by the abbreviation PCMX, is the chlorinated phenolic antiseptic 4-chloro-3,5-dimethylphenol, with the formula C₈H₉ClO and a molecular weight of about 156.61. In pure form it is a white to off-white crystalline solid with a characteristic phenolic odor, only slightly soluble in water but freely soluble in alcohols and alkaline solutions. It is a broad-spectrum antimicrobial that works by disrupting microbial cell walls and enzyme function, which is why it anchors so many antibacterial soaps, wound cleansers, household antiseptics, and hospital disinfectants. In commerce it is rarely handled as the dry solid; instead it travels as a dilute aqueous, soap-based, or alcohol-bearing concentrate. Those solutions are what fabricators actually need to store, and their relatively mild, water-based chemistry is the reason a properly selected polyethylene tank is usually a sensible containment choice.

Storing Chloroxylenol (PCMX) Solutions in HDPE and XLPE Tanks

The honest answer depends heavily on the form. Polyethylene resistance charts rate phenol itself as resistant in HDPE at ambient temperature and cresols as satisfactory near room temperature, so the dilute aqueous, alkaline, and alcohol-based PCMX antiseptic and disinfectant solutions that dominate real-world use are generally well handled by HDPE and crosslinked polyethylene. That is why we list HDPE / XLPE as Conditional rather than fully recommended. The caveats are real: concentrated phenolics can swell, soften, and stress-crack polyethylene, some chlorinated phenolic derivatives are flagged as not recommended on resistance charts, and elevated temperature worsens any solvent-polymer interaction. For routine commercial PCMX formulations, store near ambient temperature, confirm the specific resin and gasket grade against the manufacturer's chemical resistance data, and verify the active concentration. Used within those limits, a quality PE tank with compatible fittings is a practical and economical option for chloroxylenol-based products.

Material compatibility at a glance

Chloroxylenol (PCMX) is a chlorinated phenolic antiseptic that is almost always stored and shipped as a dilute aqueous, alkaline, or alcohol-based solution rather than as the neat solid. In those formulations a quality polyethylene (HDPE or XLPE) tank is a practical, economical storage option at ambient temperature once concentration and resin grade are confirmed. 316 stainless steel and Viton (FKM) are dependable for wetted metal and elastomer parts. Avoid bare carbon steel and aluminum, which the phenolic and alkaline chemistry can attack, and treat concentrated phenolic stock with extra care because concentrated phenolics can stress-crack polyethylene.

Ratings: S suitable · C conditional / limited · U unsuitable. Verify against the cited resistance charts and your concentration/temperature before specifying.

The safety that actually matters

• Treat chloroxylenol as a skin and eye irritant and a skin sensitizer; the GHS classification includes causes skin irritation (H315), may cause an allergic skin reaction (H317), and causes serious eye irritation (H319), so wear chemical-resistant gloves and splash goggles.
• It is harmful if swallowed (H302); avoid ingestion, do not eat or drink in the work area, and provide handwashing facilities.
• The solid is combustible (flash point about 135 C / 275 F); keep it away from strong heat, sparks, and open flame, and control dust during transfer of the powder.
• Avoid contact with strong oxidizers, which can react with the phenolic, and keep it away from bare carbon steel and aluminum surfaces.
• Provide eyewash and emergency shower access, and ensure adequate ventilation when handling concentrated solutions or the dry powder.
• Confirm tank, gasket, and fitting compatibility for the specific formulation and concentration before filling, and keep storage near ambient temperature for the most reliable polyethylene service.

Common questions

Can I store chloroxylenol (PCMX) in an HDPE or XLPE tank?

For the dilute aqueous, alkaline, or alcohol-based antiseptic and disinfectant solutions that PCMX is normally sold as, generally yes at ambient temperature, which is why we mark HDPE / XLPE as Conditional. Concentrated phenolic stock is more aggressive and can stress-crack polyethylene, so verify the concentration, resin grade, and temperature before committing.

What is the NFPA 704 rating for chloroxylenol?

Supplier safety data sheets report Health 2, Flammability 1, and Instability 0, with no special hazard. CAMEO Chemicals does not carry a dedicated entry, so this profile comes from manufacturer SDS data and matches the GHS irritant classification.

Is chloroxylenol flammable?

The pure crystalline solid is combustible rather than readily flammable, with a high flash point near 135 C (275 F), giving it an NFPA flammability rating of 1. It needs significant heating before it will ignite, but you should still keep it away from heat, sparks, and flame and control powder dust.

What materials should I avoid with chloroxylenol solutions?

Avoid bare carbon steel and aluminum, which the phenolic and alkaline chemistry can attack, and keep it away from strong oxidizers. Confirm elastomer choices, since phenolics and alcohols soften some rubbers; 316 stainless steel and Viton (FKM) are dependable options for wetted parts.