Polyacrylamide (PAM) in Water Treatment: Uses, Dosage, Specifications and Safety

Polyacrylamide (PAM; CAS 9003-05-8 for the nonionic homopolymer) is a water-soluble synthetic polyelectrolyte of typically 1 to 20 million g/mol that water plants dose as a flocculant, coagulant aid, filter aid and sludge conditioning polymer. PAM works at fractions of a milligram per liter, so dose basis and residual monomer decide most programs.

Drinking-water plants dose 0.05 to 0.3 mg/L (ppm) as a coagulation aid and 0.01 to 0.1 mg/L as a filter aid (Australian Drinking Water Guidelines, NHMRC), and 1 mg/L as product is the most common NSF/ANSI/CAN 60 maximum use level (NSF listings, 2026-10-21). PAM is one of the polymers in this reference of water treatment chemicals, each documented with the same identity, dose and compliance fields.

Three values frame every PAM program: the dose basis, the make-down strength (0.2 to 1 % active) and the US treatment technique of 0.05 % residual acrylamide dosed at 1 ppm (40 CFR 141.111).

The identity card below summarizes the attributes that define PAM.

Every value on this page is checked against primary sources (NSF listings, AWWA, CEN, EPA, NHMRC, WHO); see our methodology and fact-checking process.

What Is Polyacrylamide (PAM)?#

Polyacrylamide is a synthetic, water-soluble homopolymer or copolymer of acrylamide whose long chains, typically 1 to 20 million g/mol (EN 1407:2023, 4.1.3), bridge destabilized particles into settleable floc. The nonionic homopolymer has the repeating unit -(C3H5NO)x-, and anionic grades add acrylate units.

Dry PAM is a white or off-white powder of 0.5 to 0.9 g/cm³ bulk density that dissolves in cold water and gels at about 20 g/L (2 %) and above (EN 1407:2023).

Anionic, cationic or nonionic: how do polyacrylamide charge types differ?#

PAM comes in 3 charge types: anionic copolymers with sodium acrylate, cationic copolymers with quaternary esters such as ADAM-MeCl, and the nonionic homopolymer. A supplier rule of thumb (SNF Floerger, 2003) pairs anionic grades with mineral particles and cationic grades with organic particles and biosolids.

Cationic ester grades keep best below pH 6, preferably 5.5. WHO notes that anionic and nonionic residuals may sit 2 to 3 times below the theoretical acrylamide maximum, while cationic residuals may be higher. Grades by charge density are compared under anionic and nonionic polyacrylamide flocculants.

The table below compares the 3 charge types by identity, standard, target particles and food-steam status.

Powder, emulsion or solution: which polyacrylamide forms are supplied?#

PAM is supplied in 4 commercial forms: dry powder up to 90 % active, inverse emulsion at 20 to 55 % active (commonly 40 %), dewatered emulsion with under 6 % water, and Mannich solution at 4 to 6 % active. A standard emulsion holds about 30 % hydrocarbon oil and keeps free acrylamide below 1,000 ppm (0.1 %), special grades below 500 ppm (SNF emulsion handling guide, 2013). Handling of each form is set out under polymer flocculant forms.

The table below compares the 4 PAM forms by active content, packaging, storage and shelf life.

How Does Polyacrylamide Work as a Flocculant?#

Polyacrylamide flocculates by bridging: high-molecular-weight chains adsorb on several destabilized particles at once and tie them into large floc, while cationic grades add charge neutralization and patch flocculation. Bridging is favored by high molecular weight and low charge density.

Bridging needs gentle mixing: flocculation runs at a velocity gradient G of about 100 s⁻¹, against about 1,000 s⁻¹ for coagulation (SNF Floerger, 2003). Rapid mix, slow mix and G values are explained under coagulation and flocculation in water treatment.

Where Is Polyacrylamide Used in Water Treatment? Drinking Water, Sludge and Industrial Wastewater#

PAM is used in 3 water systems: drinking-water clarification and filtration, sludge thickening and dewatering, and industrial wastewater and RO pretreatment. Uses include clarification, lime softening, DAF, direct filtration, backwash water recovery and dewatering on belt presses, centrifuges, screw presses and filter presses.

The table below compares PAM use by system, with dose basis, feed point, control and source.

Drinking water: coagulant aid and filter aid#

Drinking-water plants dose PAM at 0.05 to 0.3 mg/L (ppm) as a coagulation and flocculation aid and 0.01 to 0.1 mg/L as a filter aid, according to the Australian Drinking Water Guidelines (NHMRC). A polymer coagulant aid can cut the metal coagulant dose by 40 to 80 % (EPA Six-Year Review 4, 2024). Very-high-MW anionic PAM is generally the most effective coagulant aid, including in precipitation softening (Veolia water handbook, chapter 5). In the 2006 EPA Community Water System Survey, 16 % of surface-water systems serving 100 people or fewer used a polymer, against almost 57 % above 100,000; groundwater systems stayed at 3 % or less.

Where the metal coagulant does the TOC work, see enhanced coagulation and TOC removal.

Sludge thickening and dewatering#

Sludge plants dose PAM per dry tonne of solids on an active basis: 1 to 10 g/kg (2 to 20 lb/dry ton) on belt filter presses (EPA 832-F-00-057) and 2.5 to 20 kg/t (5 to 40 lb/dry ton) on centrifuges at 95 % solids capture (EPA 832-F-00-053). Polymer programs reduce sludge volume by 50 to 90 % against inorganic coagulants, according to the same handbook.

The 4 sludge types below show how belt press doses and cake solids differ (EPA 832-F-00-057).

• Raw primary sludge: 1 to 5 g/kg (2 to 10 lb/dry ton), cake 28 to 44 % TS.
• Raw waste activated sludge (WAS): 1 to 10 g/kg (2 to 20 lb/dry ton), cake 20 to 35 % TS.
• Anaerobically digested primary plus WAS: 2 to 8 g/kg (4 to 16 lb/dry ton), cake 18 to 44 % TS.
• Oxygen-activated WAS: 4 to 10 g/kg (8 to 20 lb/dry ton), cake 15 to 23 % TS.

Centrifuges take 7.5 to 15 kg/t (15 to 30 lb/dry ton) for digested primary plus WAS, and a rotary drum thickener example runs at 5 kg/t (10 lb/dry ton) active. Polymer selection by sludge type is covered under sludge thickening and dewatering polymers.

Industrial wastewater and RO pretreatment#

Industrial plants set the PAM dose by jar test, with the polymer fed to a flocculation tank after the coagulation tank. A standard jar sequence runs 250 rpm for 10 s, 40 rpm for 5 min and about 10 min of settling, then reads clarified turbidity, suspended solids and COD.

In one study, 2.5 mg/L of a cationic polyelectrolyte treated oily water at 70 to 280 mg/L oil, against 28 to 50 mg/L of alum (LAPSE 2019); a single-study result transfers to a plant only after a jar test on the actual effluent. Coagulant and polymer pairs by industry are listed under industrial wastewater treatment chemicals.

Ahead of reverse osmosis, PAM stays in the clarifier and filters, because cationic carryover fouls membranes.

How Is the Polyacrylamide Dose Calculated and Fed?#

The daily PAM feed equals dose x flow: 0.2 mg/L as product at 10 MGD (37,854 m³/d) is 16.7 lb/day (7.57 kg/d) of a 40 % active emulsion, or 6.7 lb/day (3.03 kg/d) as active. The formulas are lb/day = mg/L x MGD x 8.34 / purity (Florida DEP) and kg/d = mg/L x m³/d / 1,000 (EOCP).

The NSF/ANSI/CAN 60 maximum use level is stated as product, summed over all application points. The worked example below labels every input; all results are calculated.

Pumps, tanks and carrier water are covered under chemical feed systems.

How do you convert a polymer dose between product, active and dry solids?#

Multiply a dose as product by the active fraction for the dose as active; for sludge, divide the active polymer mass by the dry solids mass: lb/dry ton = 2,000 x polymer gpm x active fraction / (sludge gpm x solids fraction). The metric form is kg/t = 1,000 x polymer L/min x active fraction / (sludge L/min x solids fraction).

In a worked example, 3 gpm (11.4 L/min) of solution at 0.25 % active fed into 100 gpm (378.5 L/min) of sludge at 2 % solids gives 7.5 lb/dry ton (3.75 kg/t) as active (calculated). For other flows, the dosage and feed rate calculator converts the dose to kg/d and lb/day.

How is polyacrylamide made down and activated?#

PAM is made down in 5 steps, from activation at 0.2 to 1 % active (dry) or 0.5 % active (emulsion) to injection at 0.1 to 0.25 % active; neat emulsion is never fed. The 5 steps are listed below.

1. Check the dilution water: free chlorine below 4 mg/L, hardness up to about 400 mg/L.
2. Temper the water: heat it below 4 °C (39 °F), keep it under 38 °C (100 °F) and under 30 °C (86 °F) for emulsion inversion.
3. Activate the polymer: 0.2 to 1 % active for dry grades; 0.5 % for emulsions (5 g/L active equals 10 to 15 g/L commercial product), with hydraulic emulsion units at 414 kPa (60 psi) or more.
4. Age the solution: about 30 min for wastewater, or 1 to 4 h of gentle mixing for drinking water (NHMRC).
5. Dilute to 0.1 to 0.25 % active and inject.

Mixer types and aging tanks are covered under polymer make-down and activation.

How Is Polyacrylamide Dosing Controlled?#

Plants control PAM with 5 measurements: jar tests, settled and filtered turbidity, filter headloss, cake and filtrate or centrate solids, and capture. The 5 measurements and what each shows are listed below.

• Jar tests set the dose; a 0.5 % polyacrylamide stock keeps for 1 week (Irish EPA).
• Settled and filtered turbidity show the drinking-water result.
• Filter headloss rises fast when a filter aid is overdosed.
• Feed, cake and filtrate total solids are sampled at least once per shift on belt presses (EPA 832-F-00-057).
• Centrate and cake solids set centrifuge dose, feed rate and scroll speed against 95 % capture (EPA 832-F-00-053).

Polymer stock and mixing speeds follow the jar test procedure.

What happens when polyacrylamide is overdosed?#

Overdosing restabilizes particles by charge repulsion and, with a filter aid, clogs filters. Overdosing also raises the acrylamide load. The US treatment technique caps the product of dose and monomer content at 0.05 % monomer dosed at 1 ppm (40 CFR 141.111).

What Is Polyacrylamide Compatible With? Coagulants, Oxidants and Antiscalants#

PAM is compatible with the metal coagulants it follows, but it degrades or fouls with 4 groups: oxidants, ferrous iron, hard or alkaline water for cationic grades, and anionic antiscalants. The 4 groups are listed below.

• Metal coagulants, such as polyaluminum chloride (PAC), go in first; PAM follows after pH adjustment.
• Oxidants and free chlorine in dilution water degrade the chains, and ferrous iron at 0.5 ppm degrades a PAM solution after about 2 h (SNF emulsion handling guide, 2013).
• Hard or alkaline water hydrolyzes cationic esters, and emulsions from different suppliers are never mixed (the same guide).
• Anionic RO antiscalants gel with cationic polymer carryover or aluminum and iron into a gum-like foulant that needs repeated alkaline EDTA cleaning (DuPont FilmTec Reverse Osmosis Technical Manual).

The acrylamide monomer reacts with strong oxidizers and may polymerize violently on melting (NIOSH). Other incompatible pairs are listed under water treatment chemical compatibility.

Which Standards Cover Polyacrylamide? NSF/ANSI/CAN 60, AWWA B453 and EN 1407/1410#

Four documents govern PAM for drinking water: NSF/ANSI/CAN 60 for health effects, ANSI/AWWA B453-24 for product quality in North America, and EN 1407:2023 and EN 1410:2023 in Europe. The table below compares them by scope, edition and key requirement.

What is the NSF/ANSI/CAN 60 maximum use level for polyacrylamide?#

No single NSF/ANSI/CAN 60 limit exists for PAM: maximum use levels are product-specific, and 1 mg/L as product appears on 2,599 of 4,114 product-function rows, followed by 3 mg/L (946 rows) and 3.5 mg/L (229 rows) (NSF listings, 2026-10-21). Product MULs range from about 0.2 to 160 mg/L (NSF listing tally, 2026-10-20) across 177 companies and 3,544 products (company plus trade designation).

The MUL follows the monomer content: EPA's 2024 review cites a lot with 760 mg/kg residual monomer certified at 0.6 mg/L. The 2020 text of the standard sets total allowable levels of 1.0 mg/L (dry) and 4.0 mg/L (emulsion), based on 1 mg/L of polymer at 0.05 % acrylamide. MULs and listing footnotes are covered under NSF/ANSI/CAN 60 certification.

49 US states require NSF/ANSI/CAN 60 through legislation, regulations or policies (NSF survey of ASDWA members), and 9 of 13 Canadian provinces and territories do (NSF, 2019).

What do AWWA B453-24, EN 1407:2023 and EN 1410:2023 specify?#

ANSI/AWWA B453-24 is the current North American polyacrylamide standard on the AWWA standards list (read 2026-10-20) and includes a residual monomer requirement; its predecessor B453-19 took effect on 2019-12-01 and revised B453-13. B453 sits beside B451-23 for polyDADMAC and B452-20 for EPI-DMA polyamines in the coagulation group of the AWWA B-series standards.

EN 1407:2023 covers anionic and nonionic PAM and EN 1410:2023 cationic PAM, both in solid commercial form for water intended for human consumption; no separate EN exists for nonionic PAM. CEN approved EN 1407:2023 on 2023-08-14.

How Is Residual Acrylamide in Polyacrylamide Regulated?#

Drinking-water rules regulate the residual acrylamide monomer (CAS 79-06-1), not the polymer: the US sets a treatment technique of 0.05 % monomer dosed at 1 ppm, while the EU, WHO and Australia set water values of 0.10, 0.5 and 0.2 µg/L. Acrylamide is not dosed; it is the unreacted monomer left in the product.

The table below compares the acrylamide rules and listings that apply to PAM, with their type (status 2026-10-21).

Polymer aids beside coagulants and disinfectants are shown under drinking water treatment chemicals.

How much residual acrylamide does certified polyacrylamide contain?#

Certified PAM contained a median of 49 mg/kg residual acrylamide in 307 NSF analyses from 2019 to 2021, with a 90th percentile of 260 mg/kg and a maximum of 760 mg/kg, against the 500 mg/kg that the 0.05 % treatment technique allows (EPA Six-Year Review 4, EPA-815-R-24-023, February 2024).

EPA's worst case is 0.5 µg/L of acrylamide from the polymer plus 0.05 µg/L from contact materials, 0.55 µg/L in total, and EPA decided not to revise the rule. Conventional treatment does not remove acrylamide (WHO), which detects it down to 0.032 µg/L by GC. The table below compares NSF monomer data by period.

Is there an MCL for acrylamide in drinking water?#

No: acrylamide has no MCL in the US; 40 CFR 141.111 sets a treatment technique of 0.05 % residual monomer dosed at 1 ppm, and the MCLG is zero. Each system certifies annually in writing to the State, relying on manufacturer or third-party certification. Values elsewhere are stated in µg/L, never mg/L.

Is Polyacrylamide Toxic? Safety, Handling and Storage#

Polyacrylamide polymer has no harmonized CLP classification, and 89.24 % of ECHA C&L notifications for the homopolymer report "not classified"; the hazard driver is residual acrylamide, harmonized Carc. 1B (H350) and Muta. 1B (H340). A minority self-classify it as H302 (10.5 %), so the delivered product's SDS governs.

Acrylamide carries the harmonized (CLP Annex VI) statements H301, H312, H315, H317, H319, H332, H340, H350, H361f and H372, and IARC Group 2A. NIOSH lists an OSHA PEL of 0.3 mg/m³ TWA [skin] and a REL of 0.03 mg/m³ TWA [skin] for acrylamide. Spills are extremely slippery. Containment and materials by chemical are covered under chemical storage tanks.

The table below summarizes PAM storage and handling data.

What does a polyacrylamide safety data sheet (SDS) cover?#

A PAM safety data sheet gives classification, storage, exposure and transport data for one product, which differ by form and supplier. Check the 4 items below against the delivered grade.

1. Confirm the product name, charge type, CAS number and active content against the certificate of analysis.
2. Compare the residual acrylamide statement with the 0.05 % treatment technique.
3. Check the storage section against the temperature range of the form.
4. Read section 14 for the transport classification of the delivered form.

What Are the Alternatives to Polyacrylamide?#

The 3 main alternatives to PAM are polyDADMAC, polyamine (Epi-DMA) and natural flocculants such as chitosan; activated silica is a fourth, older option. The table below compares them by identity, role, MUL, standard and monomer rule.

Polyacrylamide vs polyDADMAC#

PolyDADMAC is a low-molecular-weight cationic coagulant that neutralizes charge, while PAM is a high-molecular-weight flocculant that bridges. Veolia's water handbook guidance for cationic coagulant polymers is that below 10 NTU the polymer alone usually cannot clarify, from 10 to 60 NTU an inorganic coagulant plus cationic polymer works best, and above 60 NTU the polymer alone is normally sufficient. Grades and MULs of the cationic coagulant are on polyDADMAC.

Polyacrylamide vs polyamine (Epi-DMA)#

Polyamine is a cationic coagulant, not a bridging flocculant, and carries a parallel US monomer rule: epichlorohydrin 0.01 % dosed at 20 ppm, beside acrylamide 0.05 % at 1 ppm (40 CFR 141.111). Its most common NSF/ANSI/CAN 60 MUL is 10 mg/L, ten times that of PAM. The epichlorohydrin rule is detailed under polyamine (Epi-DMA) coagulant.

Polyacrylamide Grades, Suppliers and Sourcing#

PAM is produced by makers that include AECI Mining Chemicals, Kemira and SNF, plus NSF-listed blenders, in dry, emulsion, dewatered-emulsion and Mannich grades. Distributors and producers by region are listed under water treatment chemical suppliers.

The table below lists PAM makers named in listings and datasheets, alphabetically.

Listed alphabetically; no company is a partner of this site and none pays for inclusion.

Buyers check the NSF listing for the exact trade name and facility, because each MUL belongs to one product.

How is polyacrylamide priced and quoted?#

PAM is quoted per pound, per gallon or per wet ton of product, so two offers compare only after converting each to cost per kilogram of active polymer. A Yonkers centrifuge specification called for 40 to 50 % active emulsion (EPA 832-F-00-053).

Quote factors are charge, form and active content, package, annual quantity, freight distance, contract term and documents such as the NSF certificate.

Public procurement records show what buyers paid at a given date and place; they include delivery and local terms and are not a current price.

Each award holds for one specification and date, so send one specification and request quotes for water treatment chemicals on the same active basis.

Where Does Polyacrylamide Sit Among Flocculants for Water Treatment?#

Polyacrylamide is the polymer family behind 4 flocculant class pages: cationic, anionic and nonionic grades, emulsion and dry forms, and make-down. All polymer types are compared under flocculants for water treatment.

Other uses of polyacrylamide outside water treatment#

Polyacrylamide also serves in food wash water and erosion control, both outside this reference. 21 CFR 173.315 allows PAM at up to 10 ppm in fruit and vegetable wash water with at most 0.2 % monomer, a food rule rather than a water-treatment limit, and erosion-control and stormwater PAM sits outside the scope of this site.

Polyacrylamide FAQs#

Is polyacrylamide a coagulant or a flocculant?#

PAM is a flocculant and coagulant aid: it bridges particles that a primary coagulant has already destabilized. The primary chemicals PAM follows are compared under coagulants for water treatment.

Is polyacrylamide the same as acrylamide?#

No: acrylamide (CAS 79-06-1, C3H5NO, 71.08 g/mol) is the monomer, a harmonized Carc. 1B substance, while polyacrylamide is the polymer that carries traces of it as a residual.

How long does polyacrylamide keep in storage?#

Dry PAM keeps over 3 years unopened, emulsions 6 months at 5 to 30 °C (41 to 86 °F), and Mannich solutions 4 weeks; a 0.5 % jar-test stock keeps 1 week (Irish EPA).

Is polyacrylamide used inside boilers?#

No: PAM has no internal boiler-water use and serves only in makeup clarification; 21 CFR 173.310 lists only the anionic acrylamide-sodium acrylate resin. Internal boiler polymers are covered under all-polymer and chelant boiler programs.