- ▸ Scale inhibition: carbonate and sulfate scale control in boilers and cooling water
- ▸ Dispersant: suspended-solids and iron-oxide dispersion
- ▸ High-temperature treatment: stable threshold inhibitor for hot systems
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.
Request SDS →Hydrolyzed polymaleic anhydride (HPMA, CAS 26099-09-2) is a low-molecular-weight polycarboxylate (polymaleic acid) polymer. It is used in water treatment as a scale and corrosion inhibitor and dispersant, particularly under high-temperature and high-hardness conditions such as boiler and cooling-water systems.
Regulatory & registration requirements
- TSCA (US):
- REACH (EU): Not determined from public registry
- EC number: 607-861-7
TSCA Inventory flag XU: a substance exempt from reporting under the Chemical Data Reporting Rule (40 CFR 711) (EPA flag legend).
Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12
Frequently Asked Questions
What is hydrolyzed polymaleic anhydride (HPMA)?
HPMA (CAS 26099-09-2) is a low-molecular-weight polycarboxylate, essentially polymaleic acid, formed by hydrolyzing polymaleic anhydride. It functions as a threshold scale inhibitor, dispersant, and corrosion inhibitor in water-treatment systems.
What is hydrolyzed polymaleic anhydride used for?
HPMA is used in water treatment to control carbonate and sulfate scale in boilers and cooling water, to disperse suspended solids and iron oxide, and as a stable threshold inhibitor under high-temperature, high-hardness conditions. Its thermal stability makes it suited to hot systems where many polyacrylates degrade.
Why is HPMA used in high-temperature water systems?
HPMA is a low-molecular-weight polymaleic-acid polymer that remains effective as a threshold scale inhibitor at elevated temperatures, which is why it is applied in boiler and high-temperature cooling-water treatment. It also tolerates high water hardness.
How is HPMA supplied and what is its CAS number?
Hydrolyzed polymaleic anhydride is CAS 26099-09-2 and is typically supplied as an aqueous solution. Confirm active-solids content against the Certificate of Analysis; an SDS ships with each lot.
How do I buy HPMA in bulk?
RawSource supplies HPMA in drums, IBC totes, and larger bulk for water-treatment and dispersant applications. Request a bulk quote for current pricing, solids specification, packaging, and lead time.
What is the REACH and TSCA regulatory status of Hydrolyzed Polymaleic Anhydride (HPMA)?
Hydrolyzed Polymaleic Anhydride (HPMA) (CAS 26099-09-2) is listed as Active on the U.S. EPA TSCA Inventory; its REACH registration status is not determined from the public ECHA registry.