Acids & Salts Available — Bulk Only

Polyaluminum Chloride (PAC)

CAS 1327-41-9 · Formula Aln(OH)mCl(3n-m)

A pre-hydrolyzed aluminum coagulant for drinking-water and wastewater treatment, removing turbidity, color.

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HS Code
2827.32
At a Glance
Material Family
Acids & Salts
Record Type
Pure compound
Primary Role
Coagulation / Flocculation
Functional Roles
Safety & Handling
Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

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HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
2827 . 32
Chapter 28
Inorganic chemicals; compounds of precious metals and rare-earth metals
Heading 28.27
Internationally harmonized (WCO HS)
Subheading 2827.32
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
1327-41-9
Molecular Formula
Aln(OH)mCl(3n-m)
Synonyms & Trade Names
PAC PACl Poly aluminium chloride Polyaluminium chloride Basic aluminum chloride Aluminum chloride hydroxide
Full Description

Polyaluminum chloride (PAC, PACl, CAS 1327-41-9) is a pre-hydrolyzed, high-efficiency aluminum coagulant for drinking-water and wastewater treatment. Because it is already partially neutralized (basic), it coagulates over a wider pH range than alum, works better in cold or low-alkalinity water, consumes less alkalinity, and produces less sludge.

Polyaluminum Chloride: Applications & Grades

PAC is dosed as a primary coagulant for turbidity, color, and organics removal and for phosphorus control. Its performance is set by two numbers: % Al2O3 (strength) and basicity (degree of pre-neutralization) — higher basicity means less pH depression and better cold-water flocculation. Drinking-water grades meet NSF/ANSI 60 and AWWA B408.

PAC vs Alum

PAC (general form Aln(OH)mCl3n−m) is pre-hydrolyzed during manufacture, so the reactive aluminum species already exist before dosing — coagulation starts immediately and depends less on water temperature and alkalinity than alum:

Polyaluminum chloride (PAC) Aluminum sulfate (alum)
Effective pH Wide (≈5–9) Narrower (≈5.5–7.5)
Typical dose Lower (pre-hydrolyzed) Higher
Alkalinity use Low — less pH depression High — often needs pH correction
Cold-water performance Strong Weaker
Sludge volume Lower Higher

For the conventional alternatives, see aluminum sulfate and ferric chloride. PAC and these coagulants are often paired with a polyacrylamide flocculant as the bridging aid for clarification and dewatering.

Grades Compared

Match the grade to your water temperature, alkalinity, and feed system:

Grade Al2O3 Basicity Form Best for
Standard liquid PAC 10–12% 40–65% Solution General potable & wastewater coagulation
High-basicity PAC 10–18% 65–83% Solution Cold / low-alkalinity water, minimal pH drop
Spray-dried PAC 28–30% Powder Dry feed, freight-sensitive shipping

Applications by Sector

  • Drinking water. Turbidity and natural-organic-matter removal with low residual aluminum and minimal pH adjustment.
  • Municipal & industrial wastewater. Primary coagulation, phosphorus removal, and clarification ahead of flocculation and dewatering.
  • Paper. Sizing, retention, and pitch control.
  • Oil/water & process streams. Emulsion breaking and solids removal.

Switching from alum or need a specific basicity? Send your water temperature, alkalinity, and dose on an RFQ for the right PAC.

Regulatory & registration requirements

  • TSCA (US):
  • REACH (EU):
  • EC number: 215-477-2

Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12

Frequently Asked Questions

What is polyaluminum chloride (PAC) used for?

PAC is a pre-hydrolyzed aluminum coagulant for drinking-water and wastewater treatment — turbidity, color, organics, and phosphorus removal. It coagulates over a wider pH range than alum, performs better in cold water, uses less alkalinity, and makes less sludge. RawSource supplies NSF/ANSI 60 grades.

PAC vs alum — what’s the difference?

PAC is partially pre-neutralized (“basic”), so it depresses pH far less than alum, needs less or no supplemental alkalinity, flocculates better in cold/low-alkalinity water, and generates less sludge — usually at a lower dose. Alum is cheaper per pound. Many plants switch to PAC for performance and reduced chemical handling.

What do Al2O3 % and basicity mean for PAC?

Al2O3 % is the aluminum strength (dose basis); basicity is how pre-neutralized the product is (higher = less pH drop, better cold-water performance). A high-basicity PAC suits cold or low-alkalinity water; a standard PAC suits general use. Match both to your water on the RFQ, and bracket the dose with a jar test before committing to bulk volume.

How is PAC supplied in bulk?

RawSource supplies polyaluminum chloride as liquid (10–18% Al2O3) in bulk and totes, or spray-dried powder (28–30%) in supersacks, under CAS 1327-41-9. Grade, Al2O3/basicity, packaging, and MOQ confirmed at quotation against the CoA. Submit a bulk RFQ.

What is the REACH and TSCA regulatory status of Polyaluminum Chloride (PAC)?

Polyaluminum Chloride (PAC) (CAS 1327-41-9) is subject to U.S. TSCA Inventory requirements; supplying it into the EU requires valid REACH registration ((EC) No 1907/2006). RawSource cannot verify a third-party supplier's registrations — buyers should require documented TSCA and REACH compliance for their jurisdiction and volume (EC 215-477-2).

Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.